Yaks That Adapt to Low Oxygen Environments

There has been recent insight into adaptations, genetically and cellularly, that allow yaks to survive in high altitude environments. It has been determined that this ability to live in these kinds of environments could be a result of endothelial lung cells specific to yaks. The endothelial lung cells are a single layer lined with blood vessels that regulates the exchanges between the bloodstream and surrounding tissues. High altitude regions in the Tibetan Plateau are inhabited by both domestic and wild yaks. They experience low oxygen concentrations. Humans and other non-native mammals would experience extreme heart and lung issues if exposed to such low oxygen conditions. This is not the case for the yaks who have adapted to these conditions over millions of years.  

A group of scientists explored just how yaks are adapted to these kinds of environments by combining transcriptomic and genomic data to present an exclusive genome assembly for both domestic and wild yaks. Transcriptomic data involves characterizing all transcription activity (both coding and non-coding) or a select subset of RNA transcripts within the sample. This analysis allows for the identification of candidate genes and expressed markers of traits of interest associated. This also included a map of the different lung cell types present. 127 genes were identified to be expressed differently in yaks compared to European cattle and identified a subtype of endothelial cells only found in the lung tissue of yaks. This specific cell type was shown to express genes involved in high altitude adaptation. These findings on genetic adaptations of yaks and high-altitude environments can be useful for future studies on how other mammals respond to low oxygen environments.  

Genes Help Monkeys Stay High

            Rhinopithecus bieti, or colloquially known as the Yunnan snub-nosed monkey to people from Tibet, are a very interesting group of monkeys. Living over 4,000 miles above sea level, it is a wonder as to how they are able to acclimate themselves to not only the weather but also the altitude. So how do these monkeys remain at such high altitudes?

        

            The answer to that question may lie in the snub nosed monkey’s genes. In a genetic study of the monkeys’ DNA, it was determined that there were 19 major gene variations that contribute to the monkey’s ability to thrive at such high altitudes. As the only non human primates to live at such high elevation there must have been many things that contributed to their selection for these genes.

            Through reconstruction of the evolutionary history of these snub nosed monkeys, researchers determined that episodes of climate variation may have shaped these monkeys to what they are today. One of the major genes involved in the monkey’s ability to inhabit such high elevations is the ADAM9 gene (See genome sequenced here). Interestingly enough, there are versions of this same gene located in yaks and chickens found in Tibet. In relation to the selection of genes, the ADAM9 gene was most likely selected for its ability to allow these animals to live in such low oxygenated conditions. Similar to these monkeys, the people of Tibet also have adaptations to the high elevation of Tibet inherited from their extinct relatives known as the Denisovans. The genetic variant that has been examined to be the cause of this adaptation is known as EPAS. Thanks to genes and many years of selection, the snub nosed monkey and many others, including humans, have been able to acclimate themselves to high altitudes where the oxygen levels are scarce.
            As someone who enjoys hiking up large mountains, I think the gene like the ADAM 9 would be something that could help me personally to climb higher mountains without having to waste time acclimating to the altitude. Perhaps in the future, the ADAM 9 gene could be isolated and potentially sequenced to find a similar allele in normal human beings like me. In that way, potentially, regular people could climb higher and higher like these snub nosed monkeys or even Denisovans.  

(https://www.sciencenews.org/blog/science-ticker/genes-help-snub-nosed-monkeys-live-high-life?mode=topic&context=87)