Why Does This Species of Primate Drink Salt Water?

 The Cat Ba langur (Trachypithecus poliocephalus), or the golden-headed langur, is one of the rarest species of primate globally at around ~85 animals. Despite its extremely small population, this species has many unique adaptations-- one of which is the novel ability to drink salt water. 

Their unique island environment calls for unique adaptations in order to survive. Certain genes have been found to likely increase tolerance to drinking salt water. Whole-genome scans to detect selective genes within the langurs identified 30 non-synonymous mutations in 22 genes relating to sodium transport and homeostasis. Of these 30 mutations, 21 were homozygous and occurred only in T. poliocephalus. Analyzing genes found in other vertebrates that adapt to salinity had shown that T. poliocephalus had non-synonymous variants of ten of these genes. 

While this preliminary study has only investigated four individuals and is not conclusive in the origins of this adaptation, researchers hope it can further emphasize the importance of protecting this critically endangered species.

https://www.sciencedaily.com/releases/2024/10/241028131601.htm
https://www.nature.com/articles/s41467-024-52811-7

Social Stress Impacts Genes of Rhesus Monkeys

Scientists have long known there is a correlation between environmental factors- such as chronic stress- and the physical health of an individual. In fact,It is believed that this can actually cause a "pro-inflammatory" response. This shows that chronic stress can cause cellular/biological changes in an organism. The question the researchers at Yerke National Primate Research Center set out to answer was how long these effects can last.

An experiment was conducted using Rhesus monkeys. The monkeys were put into groups of five with one monkey introduced at a time. This created a strict social order among the monkeys, with the monkeys who were in the group longest holding the highest social position. The monkeys in high social positions would pick and bully those of lower social statuses. After a year, the monkeys were then switched into different groups and reintroduced in a new order, thus changing the social standings of the monkeys. Some monkeys who had previously held high statuses fell lower on the totem pole, others were higher, and some stayed the same.

Three blood samples were then taken from each the monkeys. The first group was simply incubated as a control, one was treated to mimic a bacterial infection, and one was treated to mimic a viral infection. The data showed that monkeys who had been in a high social standing in both groups had a better immune responses than those who had started at a lower social standing and ended at higher one. RNA sequencing of these samples also revealed that thousands of genes within these monkeys were expressed differently depending on their social ranks.

This study shows how social pressure and the concept of "biological embedding" can have drastic effects on individuals and the expression of their genes, even beyond childhood. This is fascinating to consider, especially when trying to find more links between genetics and psychology, particularly how individuals who have been exposed to psychologically traumatic evens may be more likely to have altered gene expression resulting in a decline in health.

Article: https://www.medicalnewstoday.com/articles/326755.php#5
Related Link (video related to study): https://www.youtube.com/watch?v=OYFRICCVK4M&feature=player_embedded
Related Link (Social Structure of Primate Groups): https://www2.palomar.edu/anthro/behavior/behave_2.htm

First Successful Somatic Cell Nuclear Transfer Cloning of Primates

Earlier this year, at the Chinese Academy of Science, two macaque monkeys, Zhong Zhong and Hua Hua, became the first two primates to be successfully cloned using somatic cell nuclear transfer. Some might recall that this type of cloning gained its fame in the scientific community with its first successful subject, Dolly the Sheep. Somatic cell nuclear transfer, as its name infers, works by transferring the nucleus from a mature body cell into an egg cell that lacks a nucleus. Thus, the body cell DNA is rewritten by the egg cell, and therefore returns it to its embryonic state. This rewritten embryonic cell, basically becomes a blank slate, so to speak, that can then become any cell in the body.

But why haven’t any organism so genetically close to humans, like the macaques, been successfully cloned like this before? Well according to the Mu-ming Poo, the director of the Institute of Neuroscience at the Chinese Academy of Sciences in Shanghai, the main reason primate cloning has been unsuccessful in the past, was due to a failure to reprogram the somatic DNA by the egg. This failure to reprogram the DNA is believed to be caused by an inability to unwind certain sections of the DNA that are very tightly wrapped around the somatic cells histones. To combat this and produce the successful clones found in this experiment, the researchers added specialized molecules designed to loosened these sections of DNA before its reprograming.  This breakthrough in cloning ability, will have significant implications on future disease and drug testing programs, as it could make the monkeys, which are already good genetic analogs to humans, even better test subjects, by removing any influence genetic variation between individuals might have on the trial results.

For the article this information was gathered from use https://www.sciencenews.org/article/baby-macaques-primates-clones-dolly-sheep?mode=topic&context=88&tgt=nr

And for more information on somatic cell nuclear transfer cloning use this link https://www.sciencedaily.com/terms/somatic_cell_nuclear_transfer.htm

Evolution of Bone Gene Osteocrin to Perform Cognitive Functions in Primates

Through millions of years of evolution, primates have gained the cognitive ability to think that differentiates them from other mammals. Scientists believe that the gene that accounts for this isosteocrin (OSTN), which is expressed in the neurons of primates as well as in the bones and muscles of mammals. Scientist Bulent Ataman and colleagues cultured human neurons in vitro to simulate brain activity and learn more about the OSTN gene. They then used RNA sequencing to determine upregulated transcripts, in which they found a few transcripts specific only to human neurons, the most active one being OSTN. OSTN was also found to be expressed in the neocortex (which contains cognitive functions) and cortex of primates, and was expressed in response to brain activity, which makes this gene activity-dependent.

Ataman and colleagues also discovered the presence of the myocyte enhancer factor 2 (MEF2) family in primates, which binds to DNA sequences (MREs) in the neurons, while other mammals lack this factor. Scientists believe that the creation of MREs are due to a mutation in nucleotides millions of years ago when primates split off from other mammals. While other mammals lack the MRE site, primates contain three sites, and when bound induce transcription in other genes.

Scientists have found that this gene expression regulates the shape of dendrites, the branches of neurons that send and receive signals. The scientists conclude that this factor allows the cognitive thinkingin primates as a result of learning, as the expression can change dendrites so that the movement of signals is much more efficient. This experiment is important as it explains the reason as to why humans are able to think at a higher level than other animals, and how we can retain what we have learned to make predictions and anticipate the future rather than only live in the present.

http://www.nature.com/nature/journal/v539/n7628/full/539171a.html

http://cen.acs.org/articles/94/i45/evolution-repurposed-bone-gene-brain.html

Mutated Strain of Ebola is More Deadly

Ebola outbreaks happened throughout multiple areas, but the most deadly one was the outbreak within West Africa in 2014.  There were 11,310 victims.  Researchers now believe that they have identified the reason for this flare-up of victims.  Two different groups of researchers studied this problem and reached the same conclusion.  The original Ebola strain mutated and caused the virus to be able to enter human cells more easily than before.  The exact mechanisms of the mutated virus are unknown and new research needs to be conducted on that, but the same conclusion can still be reached; people with the mutated virus have a higher risk of death.

Viruses are known to mutate at a high rate, and Ebola is no different.  But this specific mutation, the GPA82V mutation, caused a lot more harm than most.  This mutation had not died out in areas where the original strain had.  GPA82V mutation is believed to change the gene that codes for Ebola's glycoproteins.  This causes the entrance into human cells to be much easier.  

When the mutated strain was injected into primates and bats, there was an increase in the amount of cells infected.  The mutated strain killed four times as many.  On the contrary, when the more harmful strain was injected into both cats and dogs, no effect was seen.  Scientists believe that the mutated strain originated in bats and that it only effects certain species.  Since primates are very closely related to humans, it is concluded that the mutated strain would impact us in basically the same way.  Research shows that it does effect humans equivalently, but not enough data was obtained to have a clear conclusion.  This article is very startling.  If this mutated strain cannot be understood and stopped, it can easily spread to regions throughout the world.  The strain mutated fairly quickly since the initial outbreak of Ebola and deadlier strains can emerge soon.  

An Alcohol Gene?

            It’s interesting to think that there is actually a gene that is linked to the consumption of alcohol. Not only can this gene be found in human beings, but it is also found in other primates such as the African great apes and now, a nocturnal lemur from Madagascar, the Aye-Aye. This interesting gene mutation is known as A294V. This gene mutation is responsible for our ability to digest alcohol faster as well as having an affinity for it. In fact, this gene codes for the enzyme, alcohol dehydrogenase class IV otherwise known as ADH4. This enzyme is the first to catabolize alcohol during digestion. 

 So what exactly did researchers do to determine that the Aye-Aye had this gene mutation? Before we get there, it is important to note that the Aye-Aye spends sometime consuming fermented nectar found native in Madagascar from a plant called the Traveler’s Tree. Thus it can be noted that the Aye-Aye does have a tooth for alcohol, given the fermented nectar. Besides genetic analysis, researchers at the Duke Lemur Center in North Carolina gave groups of Aye-Ayes servings of regular tap water as well as servings of varying amounts of ethanol to simulate the fermented nectar. After running the experiment, researchers concluded that the Aye-Aye had a greater proclivity for the servings that contained higher concentrations of alcohol.

            

But does that mean that the Aye-Aye like to get wasted? Not exactly. For most animals, there is a selective advantage of consuming fermented foods over unfermented foods. In fact, fermented foods tend to have more calories. Interestingly enough, given that humans, chimpanzees, and gorillas all share this A294V gene mutation, it must mean that the affinity for alcohol or other fermented foods was apart of the human genetic makeup far before the modern human came about. That being said, before alcohol became something that made parties more fun, it was actually something that provided our ancestors with a greater caloric intake in order to perform more activities.  

 
(http://www.livescience.com/55470-aye-ayes-adore-alcohol.html)