Insights into cold tolerance in sable (Martes zibellina) from the adaptive evolution of lipid metabolism

The sable (Martes zibellina) is widely distributed in the northern zone of Eurasia. M. zibellina survival requires a better ability to regulate its body temperature than southern-distributed marten species. The genetic basis underlying the adaptive fat mechanism in the sable is unclear. We screened candidate genes related to lipid metabolism and absorption and compared these with orthologous sequences from other carnivores. Our goal was to determine the molecular mechanism underlying the thinner fur layer and determine if the cold adaptation of sables is associated with evolutionary changes in these genes. We found that the PNLIP and ACSS2 genes have received positive selection and the GOT2 gene has undergone rapid evolution. We performed comparative transcriptome sequencing of the sable adipose tissue and found multiple genes with different expression levels. GO enrichment analysis on the differentially expressed genes showed that they were significantly enriched in GO entries, such as lipid metabolism, lipase activity, and glucose metabolism. KEGG enrichment analysis revealed that these genes were significantly enriched in metabolic pathways and fatty acid metabolism pathways, indicating significant differences in the metabolic level of adipose tissue in winter and summer.

Automated summary

Research has found that genes responsible for lipid metabolism and absorption, PNLIP and ACSS2, have undergone positive selection, while the GOT2 gene has evolved rapidly. Comparative transcriptome sequencing of sable adipose tissue identified multiple genes with different expression levels. Enrichment analysis revealed significant differences in metabolic pathways and fatty acid metabolism pathways between sable adipose tissue in winter and summer.