Rapid adaptations of sheep to plateau and desert environments.

 

Photo credit: ILRI

Native Chinese sheep breeds, one of which is seen here grazing on the Tibetan Plateau, are serving as a climate change bellwether (photo credit: CRIENGLISH.com).

Badass Chinese sheep quickly evolved adaptations to extreme plateau and desert environments—New study

by SUSAN MACMILLAN

To paraphrase Luigi Guarino in his new and lively Science Blog series for the Crop Trust, with food demand estimated to increase by anywhere from 50–70% by 2050 (read Guarino for why the great spread in estimations), and with climate change bearing down upon us, manifested in more unpredictable and extreme climates, crop breeders will have to work faster and smarter, using all the tools at their disposal, to keep the world fed. And they will need all the diversity they can get their hands on. That’s the raw material of crop improvement, Guarino reminds us.

The same goes for livestock improvement, only, unlike the case for crop varieties, we have no similar genebanks storing the diversity of animals that would allow us to pull out of the freezer a whole goat or camel, say, the breed of which had disappeared from the world’s fields. Once gone, these animals are gone for good.

That’s one of the reasons that livestock genetics is such an important area of study. The world is losing its diverse livestock breeds at a rapid clip (estimated by the Food and Agriculture Organization of the United Nations at an average loss of two breeds every week). If we want to understand the genetics underlying the ability of some animals to withstand great heat or cold, or to resist some diseases, or to thrive on scarce water or poor fodder, we need to be conducting those investigations today, while we still have a diversity of farm animals to investigate. And most of those diverse animals are being raised in developing countries.

Among the scientists focusing on the developing world’s remaining rich farmyard diversity is Han Jianlin, who is based in Beijing. Jianlin is a livestock geneticist on joint appointment at the International Livestock Research Institute (ILRI) and the Chinese Academy of Agricultural Sciences (CAAS)-ILRI Joint Laboratory on Livestock and Forage Genetic Resources (JLLFGR), which is housed in CAAS’ Institute of Animal Science. Jianlin is one of 22 Chinese authors of a new paper published in the scientific journal Molecular Biology and Evolution (7 Jul 2016, advance access).

In this paper, the authors say, ‘Through comparisons of the genomes of sheep from extreme environments with those from contrasting environments, we aimed to identify the candidate genes, functional Gene Ontology (GO) categories and signaling pathways responsible for the rapid adaptations (i.e., over thousands of years) of sheep to plateau and desert environments. Additionally, to elucidate the evolutionary history of Chinese native sheep, a comprehensive analysis of the genomic diversity, population structure and demographic history of these animals was performed based on genomic data.’

Read the full article: ILRI