Effect of breeds on heat-evoked gene responses in sheep adipose tissue

Abstract

Sheep is one of the ungulates and critical for animal husbandry development like on grassland, whereas there are few pieces of research about their heat responses to date. In the present study, we selected two sheep breeds consisting of Mongolian sheep with evolving cold resistibility and Dorper sheep specifically bred for heat tolerance to explore how the different breeds of sheep positively respond to heat conditions. Three Mongolian sheep and 3 Dorper sheep underwent 37 $^{o}$C stress (2 h per day) during 4 weeks. The energy metabolism-associated adipose tissues of the experimental subjects were sampled, prepared and performed to RNA-seq following heat condition. Through the analysis and comparison of sequencing outcomes on such aspects as the quality control, sequence alignment and quantification, we obtained 236 annotated protein-coding genes as well as 98 long noncoding RNA (lncRNA) genes with expression differences. Following Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis measures, ten protein-coding genes were screened as active genes triggered by heat stress in adipose tissue in which candidates referred to DNAJA1, FABP1, HMOX1, NABP1, PNP, FNDC5, and PTGS2 of Mongolian sheep and PPP5C, PARP4, and SOD3 of Dorper sheep. The biological functions of the candidate genes were severally targeted to heat shock protein binding, oxidation resistance, DNA repair, and brown adipocyte differentiation. Taking these findings as a basis, we hope to promote comprehending on heat-tolerance of sheep and provide some inspiration to molecular stockbreeding.