Oct. 31, 2016 -- Recently, the Kunming Animal Research Institute of the Chinese Academy of Scientists revealed the reason for the Tibetan mastiffs’ resiliency on the plateau as compared to other dog breeds.
The scientists discovered that, in addition to the Tibetan mastiffs’ autosomal DNA being more compatible with high-altitude living, their sex chromosomes’ vessel development DNA and capillary process gene also make them suitable for places like Tibet as well.
The findings have been published in the international academic journal Scientific Reports.
The research into the inheritance mechanism for the adaptive evolution in high altitude and extreme environments has always been a hot topic in evolutionary biology. By studying people, wildlife, and domestic animals in such environments, many candidate genes were found suitable for high altitude living, including genes related to low-oxygen, energy metabolism, and DNA repair.
However, most of what we know about genes and their signal pathways for plateau-living have come from autosomal DNA, and very little in the domain of sex chromosomes. Researchers were still unclear on the role they play in adapting to high altitude.
Zhang Yaping, an academician at the Kunming Animal Research Institute of the Chinese Academy of Scientists, along with a research team led by Yu Li, a researcher from Yunnan University, have chosen the Tibetan mastiff, a unique and well-known domestic dog breed on China’s plateaus, as a research model to explore sex chromosomes’ function in adapting to life at high altitude.
The researchers have compared 175 subjects from 11 different domestic Chinese dog breeds, in areas ranging from low to high altitude, concluding that for the Tibetan mastiffs, their vascular dynamic protein’s dominant haplotype have a positive correlation with the altitudinal gradient, and “We believe that not only are their low-oxygen signal pathways and oxygen transport genes compatible with high altitude living, their sex chromosomes’ vessel development DNA and capillary process gene also make a difference.”
On October 7th, the research results were published on the website for Scientific Reports (http://www.nature.com/articles/srep35004) as “Identifying molecular signatures of hypoxia adaptation from sex chromosomes: A case for Tibetan Mastiff based on analyses of X chromosome.”
The Tibetan mastiff is a fierce breed of dogs popular on the Qinghai-Tibet plateau. They are tough, powerful, agile, guarded, and very territorial. They are very loyal to their owners, hostile to strangers on their turf, and great as guardians.
The Tibetan mastiffs are valued by the Tibetans because of their characteristics and known as the “King of Dogs.”
