THE EVOLUTIONARY SIGNIFICANCE OF MENTAL ILLNESSES

  What we call mental illness today may have, at one point, been integral to the evolution of the human brain or human beings in general. That’s what several recent studies suggest when their findings are taken together. Research has definitively shown for years that autistic people can commonly display inordinately good memory, an affinity for mathematics, an artistic talent or any number of other bizarrely acute skills. A sizable contingent of people also shows autistic traits without actually being diagnosed as autistic. For that matter, schizophrenia has been found to be a possible side effect of our own sophisticated evolution, and the fact that autism or its characteristics show up exponentially more frequently than schizophrenia in the global population bears significance. Schizophrenia, mind you, affects only around one percent of Americans, characterized by hallmark symptoms like hallucinations, delusions, confused speech and general lack of control over thought. The symptoms usually start to manifest between ages 16 and 30, and their onset is gradual, slowly increasing in severity. Men are known to be more susceptible than women, and some schizophrenia patients actually start to harm themselves and become violent. Some researchers pontificate that schizophrenia is a latent condition that gets triggered by an event that occurs in a person’s life within the aforementioned age range. These days, at least, there’s adequate medication for managing and treating it, and administration of said medication, as well as its manufacture, is informed by a superior comprehension of the complex neurology thereof.     According to an October 2017 study, 79 percent of schizophrenia’s origin is genetically determined. More recently, a new study published by Australian scientists in NPJ Schizophrenia shows a genetic pathway to schizophrenia and finds it to consist of 97 genes that correlate with genetic shifts in the brain region where schizophrenia is most observable. These findings support an age-old theory that schizophrenia could be an evolutionary side effect. Experts from the Florey Institute for Neuroscience and Mental Health, which is based in Parkville, Australia, argue that their findings here and now bolster those of a 2008 study published in Genome Biology, which basically stated that the brain eventually evolved to a point at which no further evolution could improve cognitive capability, which yielded an increase in metabolic processes that now sometimes err as psychiatric conditions including but not exclusive to schizophrenia. A co-author on the new study, named in an impossible stroke of irony Professor Brain Dean, said, “Though this is not fully understood, our data suggests the frontal area of the brain is severely affected by such changes,” referring to 566 genetic changes discovered in the very regions of the brain that exhibit schizophrenic traits. “There is the argument that schizophrenia is an unwanted side effect of developing a complex human brain and our findings seem to support that argument.” So, if schizophrenia marks the overstep of our brain’s evolution, could autism be the attempt to circumvent this evolutionary obstacle? The autism spectrum is known for enhancing normal human abilities and proclivities at the expense of social skills, to say the least, but it’s important to note that current research shows that many people who aren’t diagnosed with autism exhibit autistic traits. Some of them might be diagnosed as such if they were tested, but some of them might not be. They’re unaware of their proximity to the spectrum, and they often consider their unique traits an advantage. It’s becoming an increasingly accepted idea that we are all, in fact, on the autism spectrum to some extent. Genetic research supports this, showing that autistic traits have been part of the active human genome for a very long time.     Studies show certain autism genes in the primate genome as well, believed to predate the yet-to-be-understood bifurcation that yielded the human branch. Autism genes have been dated as being arguably over 100,000 years old, and studies suggest they’re exponentially more hereditary than schizophrenia genes. Even though a third of autism cases are chalked up to spontaneous mutations, autism typically shows frequent recurrence in certain families. This suggests that autism actually has an evolutionary purpose and is being selected — naturally. Vitamin D was scarcely understood until the 1990s, but since then, we’ve been learning a great deal about it, including its pertinence to brain development. A new animal study published on March 20 links the amount of vitamin D in a mother’s diet to her child’s behavior. Lots of clinical trials have illustrated a correlation between vitamin D deficiency during pregnancy and specifically the birth of an autistic child. This finding has been proven in studies from more than one country. One study even showed newborn babies growing up to develop autism after their mothers were found to be vitamin D deficient and compared them to siblings didn’t develop autism. [researchpaper 리서치페이퍼=Cedric Dent 기자]

NEW RESEARCH MAY DEBUNK ESTABLISHED FACTS IN EVOLUTION

  The world-renowned, American paleontologist from Harvard, Stephen Jay Gould, published his book, Wonderful Life: The Burgess Shale and the Nature of History, in 1989, and in it, he focused primarily on the evolution of animal life in the Cambrian Period, a dispensation of the Paleozoic Era. He broached parts of the subject by presenting readers with the hypothetical scenario in which time is rewound to the beginning of evolution and asking whether or not evolutionary events would all occur exactly the same way they did in our reality. He, instead, suggested that rebooting evolution would actually subject life to all the same variables as before and, thus, practically guarantee innumerable differences in how evolution would play out. Gould gave the scientific community a deeper picture of how probability factored into evolutionary history in that book, spurring the idea seen in many a movie or TV show today wherein one travels to the past trepidatiously with the fear that, should he or she so much as step on a butterfly, it could change the course of history and humanity’s future as a result. Genetic mutations and recombination constitute the variability of behaviors and phenotypic features that living organisms have, and these things account for that “Gouldian” view of natural selection. Natural selection is like a Brita filter, and all those variables are like water; theoretically, selection “purifies” the variables, at least in the sense that it solves for gene expressions that yield the greatest reproductive advantages for each species. Today, though, there are many biologists out there who disagree with this mode of thinking and, instead, embrace “convergent evolution.” This is the concept that unrelated organisms are all evolving toward some singular perfection — that there’s an ideal organism still yet to be realized by natural selection and that every species of living organisms on this planet is just a different attempt at reaching that ideal being. This “ideal” condition is typically thought to be ideal for immediate environments, mind you, not ideal the world over, so take two very different animals from very different environments and note how they have similarly adapted to their respective environments like bats and whales. Bats and whales are both naturally adept at echolocation; they don’t see with their eyes but, rather, hear how sound reverberates off of objects around them in order to “see” where those objects are. They don’t forget their surroundings easily, and they are two animals who hear better than anyone else on the planet despite existing in extremely different environments. The driving idea behind convergent evolution is that there are only a few ideal ways to adapt to any given environment, and if you look at natural selection that way as an evolutionary biologist, you can theoretically predict how an animal will evolve over time. In that case, if you time-travel to the past and accidentally step on the very first butterfly to ever exist, a very similar insect will eventually come to fruition anyway because the butterfly was already representative of a favored set of features naturally selected for that environment. Recently, a study along these lines was published in Current Biology finding further evidence that convergent evolution might actually be the optimal way to view natural selection. Several publications covering scientific news have picked it up already, talking about how stick spiders evolved in the Hawaiian Islands evolving in ways similar to other spiders elsewhere. Part of the significance of that location (the Hawaiian Islands) is that islands are always viewed as natural evolutionary labs because of their natural isolation. The target insects mostly have gold, dark or white bodies to camouflage them from birds and other predators, and the research team used their DNA to figure out how they evolved over time. Ancestors were apparently gold, yet dark and white spiders have repeatedly been produced from those gold ancestors six and two times respectively. It suggests that the environment is determining to a large degree what features will be selected, and in that environment, selection will usually be the same; however, it’s not ruling out the contribution of probability.     Other scientists recently traced the evolutionary history of tropical forests in general on this planet and found interesting insights that they think may inform the fight against global warming. Even though all tropical forests might look the same on the surface, they differ greatly. Only four percent of any tropical forest tree species can actually be found on all three continents that bear tropical forests, which are South America, Asia, and Africa. Palm fronds, for example, are ubiquitous to the point of being found not only in South American tropics but also in Asia, yet you still can’t find them in African forests. All these environments, mind you, differ in small but distinct ways — small because they’re still all tropical but distin [researchpaper 리서치페이퍼=Cedric Dent 기자]

WHAT WE DO AND DON’T UNDERSTAND ABOUT GENES

  So-called pseudogenes become unable to code for proteins at a certain point, and natural selection has been said in the past to acknowledge them. A new study reaffirms this notion but adds that natural selection influences said pseudogenes. The study was conducted by experts from Moscow State University out of the Faculty of Bioengineering and Bioinformatics, and it was published in Genome Biology and Evolution. To this day, mind you, it remains a broadly embraced consensus that genes are the building blocks of life in much the same way that atoms are the building blocks of matter. In spite of this, both scientists and philosophers are coming to doubt how pertinent genes are to the holistic understanding of biology. In lieu of the centrality of genes to this subject for more than a hundred years now, the scientific community has never managed to reach a universally acceptable, unchanging definition of what a gene even is. They’ve always tried to correlate its working definitions with human characteristics being explained by genes, but there’s never been any legitimate success in that regard. The accepted comprehension of genes thus far has been, instead, in relation to how determinative they are of those characteristics, and even that hasn’t been consistent on issues like hereditary diseases. This is why University of Exeter Professor Staffan Müeller-Wille and Max Planck Institute Emeritus Scientific Member for the History of Science Hans-Jörg Rheinberger have just written a new book, The Gene: From Genetics to Postgenomics, in which they analyze the inconsistencies of how genes have been understood over time. In the recent history, they focus at least in part on how technology has made it possible to sequence entire genomes in very short time and at very little cost. They also look at the study of biomolecular systems and the gradual evolution thereof.     “The most important insight associated with the discovery of the gene in the early 20th century was that the order in which genes operate does not reflect the order in which the human (or plant or animal) body develops,” write Müeller-Wille and Rheinberger for The Conversation in discussing the topics of the new text they’ve co-authored. “One gene is not linked to one physical trait — many genes control many traits. Likewise, a single trait is often controlled by hundred [sic] of genes forming complex networks of interaction.” The Moscow study looks just at natural selection’s role in pseudogenes encoding proteins. There are times when protein plays a less significant role in the adaptation and survival of a living organism perhaps due to environmental changes for example. Regardless of the circumstances, whatever mutations occur in the gene coding for that specific protein suddenly become no longer germane to the functions of that organism overall. “Scientists have known for a long time that, after a gene undergoes a harmful mutation, e.g. a nonsense mutation, it stops working and turns into a pseudogene,” according to Nadezhda Potapova, one of the Moscow study’s co-authors and a postgraduate in the Faculty of Bioengineering and Bioinformatics. “In this case, negative selection (the one that removes harmful mutations from the population) stops applying to it, and nonsynonymous mutations (the ones that cause the replacement of one amino acid in a protein with another) start to accumulate in the gene at the same speed as synonymous ones (the ones in which amino acids are not replaced),” Potapova adds. “Previously, this was indirectly referred to in many works with individual examples, but no full-scale research of the effect of nonsense mutations has been ever conducted before.” Now, a human genome consists of between 53 and 100 non-functioning alleles, and about 21-27 of those alleles were switched off specifically because of nonsense mutations. They’re called nonsense mutations because they can deprive a gene of its purpose and function; it’s a kind of mutation that yields terminating codon occurrence, and at terminating codons, protein synthesis just stops. Nonsense mutations can happen by way of insertions, replacements or even deletions of whole nucleic acid bases in the genetic code. It’s the large number of alleles that involve nonsense mutations that made scientists consider the possibility that there might be more sense to this than we give these mutations credit for. The research team studied Zambian population genomes from Drosophila melanogaster and found them to consist of 35 nonsense mutations on average. They focused on nonsense alleles that popped up due to the replacement of a single nucleotide. Their findings reveal that negative selection, which is the selective reduction of the rate at which a specific feature of the target population occurs) didn’t impact those facets of the flies’ coding genes, yet natural selection did to a minimal degree. They suspect this might have to do with alternative splicing, which is another way to read the same region of DNA by shifting the start and end points of the loci being read. “We used Drosophila melanogaster genomes. Based on it, we managed to confirm that nonsense mutations actually switch off single exon genes (i.e. the genes that contain no introns cut out during protein synthesis), and they start to accumulate both synonymous and nonsynonymous mutations at the same speed. In multi-exon genes (genes with several introns) only the exon with the mutation seems to be left out, and the others remain under the influence of negative selection, though slightly weakened,” Potapova explains. [researchpaper 리서치페이퍼=Cedric Dent 기자]

THE INSIGNIFICANCE OF PARENTING IN DEVELOPING CHILDREN’S PERSONALITIES

  One of the biggest fears most common to expecting parents is that they will unwittingly ruin their children as people in some way. No one wants to raise a sociopath or stunt a child’s ability to mature into a well-adjusted adult, so it’s common to spend lots of time during the pregnancy worrying about how to parent the child with respect to any of a variety of issues. Research shows, of course, that genetics determines far more of who a child will grow up to be than we used to think, and as we learn more and more about just how much this is the case, it’s beginning to beg the question: does parenting have a meaningful effect? Daniel Engber, a family writer for Slate, suggests that parenting doesn’t matter much as long as you don’t deviate from the ways in which you’re likely to parent. This can seem like an almost teleological statement, but he backs it up with scientific research. On the other hand, though, there are a lot of personality traits that are influenced by hidden forces other than genetics, which suggests that parenting could still play every bit as large a role as you’re inclined to think in the first place. Those same forces can be so random that they may also serve as a reason why parenting, once again, seems to become insignificant. Everyone can agree that a child can’t just simply be left to his or her own devices, but the development of a child’s personality is an incredibly complex phenomenon that no one fully understands yet. Recent research suggests that there are other biological aspects in addition to genetics that factor into it as well, further complicating the issue. These factors range anywhere from the microbes in a kid’s gut to hormones or a child’s immune system, and the research on any one of those as contributors to a personality’s maturation is voluminous at this point, believe it or not. Two traits that parents fear for the children to have or not have to varying extents, for example, are neuroticism and conscientiousness, and think about the ramifications of determining that these things, which factor greatly into physical and mental health, might be the products of biological factors that no one — not parents, not pediatricians, not therapists, not teachers — takes into consideration. Gordon Allport is viewed as one of the founding fathers of personality psychology in the US, and in 1961, he wrote that believed “sometime in the distant future, well-proven facts concerning personality will be found to interlock with well-proven facts of human biology.” Those correlations are slowly but surely being made today. Cortisol is a hormone that we release when we’re stressed, and there’s a preponderance of old research attempting in vain to correlate it with personality. Those studies largely relied on saliva swabs, though, which is now understood to be the wrong method for testing cortisol’s area of effect since a person’s cortisol levels fluctuate pretty wildly in any 24-hour period. A study published late last year, in contrast, circumvented that obstacle by analyzing cortisol in people’s hair; the study’s cohort consisted of a whopping 2,000 subjects who also completed surveys. The three centimeters of hair they took from each volunteer served as documentation for cortisol levels for the past three months like rings in a tree might show all the events endured by said tree as of late.     Participants’ conscientiousness scores on the survey correlated with their cortisol observed levels, and inherently, this suggests that conscientiousness tends to go with a relative lack of stress compared to other people. Another study similarly found that neuroticism correlates rather bizarrely with the microbacterial content of one’s gut. Once again, it’s significant because neuroticism is a trait that encompasses how prone people are to hostility, anger, worry and low moods. This study was also published last year, and the research team reached their findings based on DNA extrapolated from 672 fecal samples matched to survey answers from the participants who volunteered their stool. Slate’s Daniel Engber touts what he calls the “weird-shit rule.” Obviously, there’s nothing official about it, but it does have an academic basis to its underlying rationale. “When behavioral geneticists study pairs of fraternal and identical twins, including those who grew up together or separately, and measure how they differ as adults, they tend to find very little impact from what they call the siblings’ ‘shared environment,’” Engber explains, defining that shared environment as “the set of factors that includes whatever aspects of their lives those kids might have in common if they lived together: things like their neighborhood or school, or their parents’ personalities, social class, and strategies for raising children.” Engber essentially poses the question on that basis: “what does affect a child’s future?” He cites about 3,000 published studies on twins conducted between 1958 and 2012 that ultimately point to the idea that DNA is the strongest determinant of the personality a child will mature into as an adult. He backs them up with The Nurture Assumption, a book written by the well-known psychologist, Judith Rich Harris. In essence, the consensus isn’t much of a consensus, but the science suggests that parents change and kids don’t; ergo, much of the change in children from the perception of adults isn’t what it seems. More importantly, parenting is not what’s causing children to become the people they’re gradually becoming, especially considering how close they are to being those people from the earliest of ages. This feeds what Engber says is a thriving philosophy of parenting in academic circles these days that suggests kids will be who they’ll be so long as parents don’t do anything too weird to throw them off the path to their ideal maturation. [researchpaper 리서치페이퍼=Cedric Dent 기자]

COCKROACH DNA SEQUENCED TO IDENTIFY GENES THAT ARE KEY TO ITS SURVIVAL

  The cockroach is one of the insects that everybody wants to kill. It is often found in dark and moist corners of homes, dining establishments, and offices, specifically in toilets and in the kitchen. Chinese researchers sequenced the DNA of the American cockroach to discover the secret to the insect’s ability to thrive in some of the most disgusting places on Earth. To understand how the species – which was introduced to the US from Africa in the early 16th century – succeeded in filthy and unsanitary corners, scientists deciphered the genetic makeup of the Periplaneta Americana, or the American cockroach, The Guardian reported. Over 20,000 genes Shuai Zhan, a researcher at the Institute of Plant Physiology and Ecology in Shanghai, China, discovered that the American cockroach has more than 20,000 genes which make its genetic code as large as that of humans. An unusually large group of genes apparently helps the cockroach survive in filthy places it has adapted to. The expanded set of genes help the cockroach sense the smell that comes from food, particularly fermented food which the insect likes the most. It has another group of genes that make up the internal detoxification of the insect that protect the cockroach if it eats anything toxic.     There is another set of genes that boost the immune system to fight infection from the germs the bug encounters. All these genes make the cockroach more resilient despite the filth of its environment. Another set of genes ensure that the cockroach reproduces at an impressive rate, while there are genes that explain the ability of the insect to regrow any limbs that are broken or eaten by predators. Shuai said that by identifying the genes that are key to the cockroach’s survival, researchers hope to find ways to better control the bug’s population. The study was published on Tuesday in Nature Communications journal. He added that their findings help people fight the growing pest that spreads disease, causes allergies, and turns homes into a stinky mess. But there are actually only 30 out of the 4,500 species that actually live near people, Shuai said. He stressed that the harm of the American cockroach is becoming more serious about the threat of global warming. The study shed light on controlling and making use of the species. Comparisons to related species Besides sequencing the genes of the American cockroach, the researchers also compared it to the genes of two related species, Gizmodo reported. These are the Australian cockroach (Periplaneta australesiae) and smokybrown cockroach (Periplaneta fuliginosa). The researchers also compared the American cockroach to genetic data from other insects that belong to the same order of Blattodea. These include the termite and the German cockroach (Blatella germanica). Genomeweb noted that the Periplaneta Americana was sequenced to 295 times coverage, but the Australian cockroach and the smokybrown cockroaches were sequenced to about 40 times coverage for comparison.  They found that the American cockroach’s genome to be 3.38 gigabases large. But they observed that 60 percent of its genome is made up of repetitive elements. The researchers found that the American cockroach has 21,336 protein-coding genes, 95 percent of which are expressed. The researchers also uncovered 479 Blattodea-specific gene orthologs. They then used the genomes to build a phylogeny which indicated that the Blattodea is monophyletic. They discovered that the American cockroach has one of the largest genomes known to exist among insects. It was second to the common locust. But the species was genetically very close to two Periplaneta cockroaches. When the researchers compared its genes they found that it was more related to two species of termites than to the German cockroach. These are the dampwood termite (Zootermopsis nevadensis) and the fungus-growing termite (Macrotermes natalensis). The researchers said that the discovery means that American cockroaches could serve as a valuable model to study the evolutionary relationships between termites and cockroaches. They also found evidence that certain families of genes of the cockroach have become more expansive over time, specifically those associated with detoxification and chemoreception. Chemoreception refers to the ability of the insect to smell and taste the world around it. The researchers noted that the American cockroach has accumulated a very large stockpile of genes that provided the insect with more bitter taste receptors. It likely has helped the species expand across the world by letting the cockroach stomach a wide variety of food wherever the insect ends up. The detoxification genes help the cockroach survive and evolve resistance to chemical weapons that humans have developed against the insect. The gene expansion in families like the cytochrome P450 enzymes helps the cockroaches resist insecticides and survive in extreme environments. The American cockroach has a number of gene expansions that enables it to adapt to urban environments. It is because the species encodes 154 olfactory receptors – which is twice as many as other Blattodeans – 522 gustatory receptors, and 650 ionotropic glutamate receptors. [researchpaper 리서치페이퍼=Vittorio Hernandez 기자]

NO CONSISTENT DIFFERENCE BETWEEN FIELD AND LABORATORY ANIMALS

  Because it is a common practice in biological sciences to use animals maintained in the laboratory to draw conclusions about the ecology and evolution of animals in the wild, researchers decided to compare results using both field and laboratory animals.  Their aim was to check the assumption that laboratory populations represent their wild living counterparts. When the researchers looked for previous studies, they found 28 relevant studies on seven orders of invertebrates or a total of 777 traits, Scientific Nordic reported. But the studies did not show any significant trend in the size, lifespan, or stress tolerance of the animal studied. No evidence The researchers failed to find any evidence that the laboratory animal has been changed because it was raised in a lab. The lack of any consistent pattern was evident even if the team limited their search of the Drosophila, a type of fly. Because the Drosophila is a popular laboratory animal, it has numerous laboratory stocks of multiple species available globally. Scientists who do not have time or resources to collect fresh samples of the fly for each experiment can tap the stocks available. The researchers got nine newly collected populations from the same location as nine existing Drosophila laboratory populations with assistance from scientists in Australia, Japan, and the US. They tested 12 traits, including the fly’s ability to cope with stress, particularly the lack of food and water, exposure to harsh temperatures, how big and fat the fly was, how it reproduces, how long the species lives, and how active the Drosophila is. Although the team found that while the field and laboratory populations of the flies can be a little different from each other, there is no consistent difference. One such difference, although it is not consistent, is that the flies from the lab sometimes died sooner than the field flies. However, it was not an indicator that the lab flies were substantially different compared to wild flies. The verdict of the team is that the biggest difference in traits happened among the different species instead of whether it was kept in a lab or in the wild for several generations. The implication is that it is okay to use the lab animals for comparative studies and even ecological studies. No significant difference The researchers found no significant difference in the ecological trait correlations between the animals from the recent collections and those from the lab. Creatures that came from the cold environment were still better at coping with cold, even after it was made to live in a cozy laboratory environment compared to those that came from warm environments. The conclusion was that 20 or even 100 generations in the laboratory environment is not enough to undo the millions of years of evolution that created the species differences. The laboratory flies did not become soft because in a constant lab environment it has easy access to food, water, and mates. The relief that it offers for researchers is that they do not have to go out in the field and collect wild specimens every time they need to do an experiment involving animal models. The study was published in the Journal of Evolutionary Biology.     Virtual lab animals Among the most popular animals used in the lab are rats, mice, rabbits, and other creatures that have long played a big role to evaluate the safety and effectiveness of drugs before these undergo their first clinical trials involving humans. The Talking Democrat estimated that around 60,000 animals are used each year around the world in labs for tests and studies. To avert animal suffering, a team from Oxford University developed a computer simulation which can predict if drugs are toxic to the heart or not. Virtual Assay, the software, uses a model of the human heat cells which makes it possible to eliminate from the outset medication that is toxic to the heart without using text animals. The model was able to predict if a drug or a compound could cause an irregular heartbeat, arrhythmia, in 89 percent of the time. When researchers performed a similar test on cardiac cells of rabbits, the test was effective only 75 percent of the time. Elisa Passini, a researcher at Oxford’s computer science department, said these new models could save many animals one day and avoid killing the creatures in the name of science. She noted that the current strategies to evaluate the cardiotoxicity of medications involve using various animal species for preclinical studies. It can go beyond the use of 60,000 animals a year. But while the new virtual tests are apparently more effective than animal tests, it remains unseen if the option could be extended to all types of test. The researchers are currently holding virtual studies in the areas of type 2 diabetes and pain research. For the study, published in September in Frontiers in Physiology, the researchers won the NC3Rs award given by the National Center for the Replacement, Refinement and Reduction of Animals in Research. [researchpaper 리서치페이퍼= Vittorio Hernandez 기자]

NUMBER OF GENES KNOWN TO INCREASE STROKE RISK TRIPLES TO 22

  There are now 22 known genes that are considered genetic risk factors for stroke. The number tripled after researchers held the MEGASTROKE study which was published on Tuesday in the Nature Genetics journal. For the research, the scientists studied the DNA of more than 520,000 people all over the world. They compared the genes of patients who suffered different types of strokes with those of healthy volunteers. New ways of increasing risk The researchers said that around one-third of the newly discovered genetic variants, which are different versions of a gene, are believed to increase the risk of stroke by increasing a patient’s blood pressure. But the remaining two-thirds appear to hike the risk of a stroke in completely new ways. The other genetic influences include coronary artery disease and venous thromboembolism. They said that one specific gene boosted a person’s risk of two very different types of stroke. These are the hemorrhagic stroke in which a blood vessel bursts and bleeds into the brain, and the ischemic stroke in which the blood supply to the brain is blocked by a blood clot. The discovery could open the door for a new medication to help cut the risk of a person suffering from the two common types of stroke, the British Heart Foundation reported. Sir Nilesh Samani, the medical director of BHF, said that by helping the foundation better understand what causes a stroke, the study will help cardiologists prevent it from occurring and to develop desperately needed new treatments that could ultimately save lives. He noted that despite the availability of exciting new developments in treating strokes, which includes clot-bursting treatment and clot retrieval devices, the options at the disposal of doctors for the treatment and prevention of strokes are still far too limited. In the UK, around 38,000 people die each year after suffering a stroke. Of those who survived, there are 1.2 million people living with the cruel and debilitating after-effects of the ailment.     Biology and pathways leading to stroke The study provided extensive novel insight on the biology and pathways leading to stroke. Professor Martin Dichgans, the director of the Institute for Stroke and Dementia Research at the Ludwig Maximilians-University in Germany, pointed out that the extent to which individual variants modify stroke risk is very small. It requires a large number of subjects to discover those variants. But the university leveraged extensive datasets established by numerous researchers over the past few years. Stephanie Debette, a professor from the University of Bordeaux and Bordeaux University Hospital in France, emphasized the value of international collaboration across different ethnic origins when conducting a study of the genetics of complex, common diseases such as stroke. The researchers based their study on DNA samples of 520,000 European, North American, South Americans, Asian, African, and Australian participants. Of the total number, 67,000 had a stroke, Sci-News reported. Development of stroke drug Dr. Susha Seshadri from the University of Texas Health Sciences Center, San Antonio said that the identification of genetic regions strongly correlated to stroke will boost potential targets for the development of stroke drugs. The researchers identified 32 genomic regions associated with stroke from the millions of genetic variants they analyzed. Two-thirds of the genomic regions were novel. Seshadri explained that strokes can begin from alterations in different parts of the vasculature, including the large arteries, small arteries, the heart, and the venous system. The researchers found that genetic risk factors were implicated in each of these mechanisms. Some of the genetic risk factors contributed to specific mechanisms, while others to stroke susceptibility at large. Among the significant discoveries of the researchers is that shared genetic influences between stroke caused by vessel occlusion – which is the most common cause of stroke – and stroke caused by the rupture of a blood vessel – which is the most catastrophic cause of stroke – are often thought to have opposite mechanisms. But when the researchers studied closely the genomic areas pinpointed in the study, they observed that several of these overlap with genomic areas known to be implicated in related vascular conditions. It included atrial fibrillation, coronary artery disease, venous thrombosis, or vascular risk factors, particularly hypertension and less so, hyperlipidemia. When the scientist added data on gene expression, protein expression, and other characteristics in multiple cell types and tissues, they got first insights into the specific genes, molecular pathways, and cell and tissue types through which the new genetic risk factors can cause a stroke. They also discovered that the genes which were identified as enriched in drug targets for antithrombotic therapy are used to re-open occluded blood vessels in patients with acute stroke or to prevent vascular events, including stroke. Dr. Bradford Worrall, a researcher at the University of Virginia School of Medicine, said these findings show the potential of genetics for drug discovery. Seshardri added that vascular disease in the brain, which is a series of strokes, can lead to dementia. By understanding these newly identified risk factors for stroke, it should enable the medical community to also find novel treatments for dementia. [researchpaper 리서치페이퍼= Vittorio Hernandez 기자]

DEMYSTIFYING THE ORIGINS AND FUNCTIONS OF SEX CHROMOSOMES

  Dennis Venema, a well-known biologist, published a book entitled, Adam and the Genome, and much of the content relates directly to findings of studies published by other researchers after the release of his book. In particular, the book briefly talks about Y-Chromosome Adam and Mitochondrial Eve, which is not an actual reference to the Biblical characters so much as an allusion to the origins of the X and Y chromosomes. A new study published in Communications Biology on March 8 elucidates the provenance of male-female differentiation as a concept, focusing on the evolution of sex chromosomes, finding these origins to be surprisingly unsophisticated. Adding to the lack of sophistication, another study conducted by experts at Linköping University debunks the conjecture that the X chromosome factors significantly into the differences in male and female lifespans. By and large, people agree, regardless of their perspectives, that humanity all traces back to some singular source overall. Whether you accept Darwinism or not or only in part, you likely agree that your idea of the source, for lack of a better word, applies to everyone. As such, this typically means we can agree that there s a common, universal ancestor. Delving only slightly further, most would even venture to say that there is a common male ancestor and a common female ancestor, which is what this X- and Y-chromosome origin issue is about. The Biblical Adam and Eve references are usually just one of many points of contention that start there, but it speaks to a question that persists regarding the true origin of mankind.     In the chromosomal sense, the real question is whether or not this Adam and Eve coexisted or might have existed separately as members to a much broader populace responsible for the majority of our genome. In the former case, they would likely be the progenitors of our entire genome together whereas, in the latter case, they would independently have been the sources of only our mitochondrial DNA and Y chromosomes. Such is the general trajectory of the debate, and our autosomes (non-sex chromosomes) would be attributed to that broader populace in the latter case. Venema doesn’t really address the question in his book but, rather, glosses over the debate to make the seemingly more important argument that Mitochondrial Eve and Y-Chromosome Adam could have both existed concurrently and not have been the Biblical characters their retroactively given names imply. Even as he dodges the bulk of the debate, it’s an argument worth making, and it would then simplify things if found to be true. One might be inclined to simply dismiss this and say that there’s no way it’s that simple, but sex chromosomes aren’t proving to be very complex lately. The researchers who published the Communications Biology study concentrated their efforts on two particularly insightful, multicellular volvocine species found in the Eudorina and Yamagishiella genera. These genera collectively relate to the known transition to male-female differentiation from what is known as isogamy — the lack of sex chromosomes. Eudorina and Yamagishiella colonies look very similar to one another, both bearing 32 discernible cells, yet Yamagishiella is actually isogamous whereas Eudorina has male and female gametes. The research team determined mating types for Yamagishiella by subjecting its chromosomal regions to high-throughput genome sequencing, and they discerned male-female differentiation for Eudorina. Then, they compared those regions from both.     The theory of evolution technically is, at least in part, predicated on the notion that there should be greater genetic complexity to Eudorina than for other volvocine species, but the opposite was actually proven by the results of the study. Eudorina was found to be genetically the simplest sex-determiner of its species, which means that the most important contrast between male and female Eudorina might be little more than having or not having one gene: MID. It sits in a minuscule chromosomal region. “This new study punches a hole in the idea that increased genetic complexity of sex chromosomes accompanied the origin of sexes,” according to the lead researcher, Umen. “Moreover, the work also has practical implications since it expands our understanding of how to identify mating types and sexes in new species of algae that we might want to breed as crops for improved traits relating to biofuel or biotechnology applications,” Umen added. This level of simplicity suggests that we may also be attributing more things to sex chromosomes than actually makes sense, especially X chromosomes. Mitochondrial DNA being as important as it is, we often can’t help but figure it has something to do with just about everything. It only seems fitting, for example, that it would have major bearing on lifespans. At the very least, many have long pontificated that the presence or absence of an X chromosome might explain differences in male and female lifespans. Males average shorter lifespans, but the research team in Sweden from Linköping University published findings in Evolution that suggest this isn’t because of males having one fewer X chromosome. Mind you, this isn’t only a trend in human beings but, rather, one observed in virtually all mammalian species. Across each such species, females average longer lives. Not only that, for other species in which the males have two copies of the X chromosome — different types of fish, birds, insects, and reptiles, for example — the males also average longer lifespans. This is what gives life to the so-called “unguarded X hypothesis.”     “The fruit fly is a useful model organism to test the hypothesis,” according to Martin Brengdahl, a Ph.D. student at LiU in the Physics, Chemistry and Biology Department. He says this because “females generally live longer, and the X chromosome constitutes as much as one-fifth of the genetic material. If the theory is true, the effects should be clear in the fruit fly.” In other words, that’s where it’s most observable. So, they redistributed X chromosomes for two groups of male and female fruit flies. “There was no difference in average lifespan between females that had been inbred for the X chromosome and normal females. Inbreeding of one autosomal chromosome, on the other hand, did have a negative effect and the effects were equally large in females and males,” Brengdahl explained. This all suggests that X and Y chromosomes both might be less sophisticated than we make them out to be, which can only be surmised as a scientifically ironic commentary on the likelihood that we make more than we should of differences between sexes in general, some say. [researchpaper 리서치페이퍼=Cedric Dent 기자]

FLOATING FOR A YEAR IN SPACE STATION CHANGED ASTRONAUT SCOTT KELLY’S DNA, TWIN STUDY REVEALED

  Floating in zero gravity in space for one year has changed the DNA of NASA astronaut Scott Kelly. He and his twin brother, Mark, also a NASA astronaut, are part of the space agency’s Twin Study. After he set a world record by spending 340 consecutive days aboard the International Space Station, Scott’s DNA has changed and he grew two inches in height while he stayed in space between 2015 and 2016. More than becoming taller than Mark, the telomeres of Scott’s actually become significantly longer in space. Space genes activated CBS reported that hundreds of Scott’s space genes were activated by his year-long flight which reportedly changed the astronaut’s immune system, DNA repair, bone formation networks, hypoxia, and hypercapnia. But upon his return to Earth, Scott’s height and 93 percent of his DNA returned to normal. Nevertheless, there was a seven percent change in his genes which may stay that way. The researchers explained that the change in his DNA could be caused by the stresses of space travel that can cause changes in the biological pathways in a cell and the ejection of DNA and RNA.   Also upon his return to Earth, Scott’s mental reflexes and accuracy went down significantly. NASA blamed it on his re-exposure and adjustment to the planet’s gravity. Twin Study Meanwhile, NASA said that the Twin Study propelled the space agency into the genomics era of space travel. It was a perfect nature versus nurture study with Scott staying at the ISS and Mark remaining on Earth. Prior to the launch of the Twin Study, NASA had a grasp of what happens to the human body after astronauts spend six months at the ISS which is the standard duration. However, in the case of Scott, his one-year mission is a stepping stone to a three-year mission to Mars. After the NASA team measured a large number of metabolites, cytokines, and proteins, the researchers learned that astronauts who go on a space flight go through oxygen deprivation stress, increased inflammation, and dramatic nutrient shifts which affect gene expression. When the team presented the unexpected finding in 2017 that Scott’s telomeres became longer, the researchers verified the unexpected change with multiple assays and genomics testing. But the majority of the telomeres shortened two days after he returned to Earth.     The research team is integrating and summarizing the findings and is evaluating the possible impact of the findings on future space travel beyond low Earth orbit. The team is expected to publish later a paper on its findings, while a series of smaller papers grouped by related research areas will likewise be released. Preliminary result CNN reported that the preliminary results from the study of Scott and Mikhail Kornienko, a Russian cosmonaut, were released last week at the yearly Investigator’s Workshop for NASA’s Human Research Program. The team is made up of 10 groups of researchers who are looking at a wide variety of information about the health of the Kelly twins. It includes their immune response, bone formation, gut microbiome, and how their DNA might be affected by living in space.     After the researchers performed genome sequencing of the DNA and RNA from white blood cells of Scott and Mark, they found that the twins have hundreds of mutations unique to each man. There are over 200,000 RNA molecules that were presented differently. The chemical modifications to Scott’s DNA decreased while he was in space. However, it returned to normal upon his return to the planet. The researchers said that the modifications only show how sensitive the genes are to changing environments, whether in space or on Earth. The researchers explained Scott’s longer telomeres while in space to an increase in exercise and decrease in calorie intake while on the station. They said that Scott experienced declining bone formation, but most of the levels of his healing hormones that help with bone and muscle health increased. The scientists said it is likely because of all the exercises that astronauts perform in space daily to battle bone and muscle loss. While Scott’s level of cortisol, the stress hormone, remained normal, he suffered from a spike in inflammation as soon as he landed on Earth. The researchers explained it to the stress of re-entering the atmosphere. The twins had differences in the bacteria in their digestive system. It was expected because they were living in different environments and eating different foods. In the case of Scott, two of the main bacterial groups switched dominant positions in his microbiome between the astronaut’s time in space and on Earth. In March, Scott and Kornienko went through a series of tests after they got back to Earth from their year in space. When their capsule landed upright on dry land, the two had to maneuver themselves halfway out of the capsule before they were assisted out. Scott is convinced that it would be easier to leave the capsule on Mars because of the lesser gravity on the red planet. [researchpaper 리서치페이퍼= Vittorio Hernandez 기자]

FUNNEL-WEB SPIDER AND MOUSE SPIDER MORE CLOSELY RELATED THAN PREVIOUSLY THOUGHT

  A report from Marshal Hedin at San Diego State found that two venomous spider species are more closely related than previously thought. The report identified them as the funnel-web spider and mouse spider. The study analyzed the Atrax robustus and Missulena species of spiders. While funnel-webs spiders are considered one of the deadliest species, the mouse spider is also dangerous but not lethal. The researchers studied the venom protein from the two spider species and found it to be similar.     Antivenoms When scientists developed antivenoms to treat bite victims of the funnel-web spider, they discovered that the antivenom could also be used on victims of mouse spider bites. The researchers, led by Hedin, collected subgenomic DNA from several species of the two spiders, and they determined that the two species are closely related. Their bases in reaching the conclusion that the funnel-web spider and mouse spider are closely related were all the biological similarities between the two species such as the venom and antivenom. Hedin attributed it to a common ancestor between the two species in the report titled “Phylogenomic reclassification of the world’s most venomous spiders (Mygolomorphae, Atracinae), with implications for venom evolution.” The two species are native to Australia and were misplaced in the genetic tree that led to the reclassification, The Daily Aztec reported. The lab said that the study refutedly shook up the phylogenic tree. The spiders were believed to have diverged from a common ancestor more than 200 million years ago. Reconstructing the ancestral venom protein Hedin said that given the knowledge on what the venom proteins look like in each of these two taxa, researchers can actually reconstruct the ancestral venom protein that would be found in the common ancestor. Scientists can actually make antivenom that would target it so that the result would be more of a general purpose antivenom that works for all of the potentially dangerous spiders. Hedin disclosed that a reasonable number of people get bitten every year by the two species, but nobody dies from the bite anymore because of the wide availability of the antivenom, Newscenter reported. Shahan Derkarabetian, the co-author of the report, said that when the relationship between the two species of spiders was confirmed, they were both surprised simultaneously and expected it.  There were, after all, previous studies that indicated the two species might be closely related, although their results were never 100 percent conclusive.     However, with the data they collected, the scientists were able to provide enough support for the close relationship that would allow the researchers to say with certainty that the funnel-web spider and the mouse spider are each other’s closest relatives. It helped that the researchers were able to use museum specimens for the species, Derbarabetian, a graduate of San Diego State University who joined Harvard University recently in a postdoctoral research position, said. He considers it exciting to have the ability to include specimens that have been sitting in museums for up to 30 years. He pointed out that for genetic analysis like this, typically, researchers need fresh samples preserved specifically for genetic work. Derbarabetian said that most standard museum pieces are not preserved this way. But the laboratory method they used allowed the researchers to sequence the museum specimens and provided the scientists a lot of very usable data. With assistance from biologists in New Zealand and Argentina, Hedin and his team collected new spiders from both branches throughout Australia, while they also sought out museum specimens and used his own collection to come up with dozens of specimens that represented various branches of spiders which were both closely and distantly related. While the analysis confirmed the two species are closely related, it is still unclear exactly when the funnel-web spider and the mouse spider diverged from a common ancestor.     Hedin, besides studying spider species, also looks into the diversity and evolution of other arachnid species. For instance, Casey Richart, a doctoral student, focuses on millipedes and harvestmen. It is an order of arachnids which do not produce silk or venom. The two species are some of the earliest species to live on the land, however, their movement and disbursement are limited. The scientists could test the older and more recent evolutionary and biogeographic hypothesis because of the early, evolutionary history. The lack of movement by the two species allowed researchers to ask a very recent hypothesis on the effects of the last glacial maximum during the Pleistocene on the organisms. Richart said he tried to correlate what the evolutionary scenarios are that were affected by its evolution. Hedin also discovered the existence of three entirely new taxonomic families of spiders which adds to the more than 35,000 distinct species of spiders in the world, IBT reported.  The team published the result of their study in February in Nature Scientific Reports. To reflect these changes, online taxonomy databases have already started to update, Hedin said. [researchpaper 리서치페이퍼= Vittorio Hernandez 기자]