Transcriptome Comparison Reveals the Difference in Liver Fat Metabolism between Different Sheep Breeds

Taotao Li; Meilin Jin; Xiaojuan Fei; Zehu Yuan; Yuqin Wang; Kai Quan; Tingpu Wang; Junxiang Yang; Maochang He; Caihong Wei

doi:10.3390/ani12131650

Transcriptome Comparison Reveals the Difference in Liver Fat Metabolism between Different Sheep Breeds

Animals (Basel). 2022 Jun 27;12(13):1650. doi: 10.3390/ani12131650.

Authors

Taotao Li¹, Meilin Jin¹, Xiaojuan Fei¹, Zehu Yuan², Yuqin Wang³, Kai Quan⁴, Tingpu Wang⁵, Junxiang Yang⁶, Maochang He⁶, Caihong Wei¹

Affiliations

¹ Key Laboratory of Animal Genetics and Breeding and Reproduction, Ministry of Agriculture, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
² Joint International Research Laboratory of Agriculture and Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou 225009, China.
³ College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471023, China.
⁴ College of Animal Science and Technology, Henan University of Animal Husbandry and Economy, Zhengzhou 450046, China.
⁵ College of Bioengineering and Biotechnology, Tianshui Normal University, Tianshui 741000, China.
⁶ Gansu Institute of Animal Husbandry and Veterinary Medicine, Pingliang 744000, China.

Abstract

Hu sheep and Tibetan sheep are two commonly raised local sheep breeds in China, and they have different morphological characteristics, such as tail type and adaptability to extreme environments. A fat tail in sheep is the main adipose depot in sheep, whereas the liver is an important organ for fat metabolism, with the uptake, esterification, oxidation, and secretion of fatty acids (FAs). Meanwhile, adaptations to high-altitude and arid environments also affect liver metabolism. Therefore, in this study, RNA-sequencing (RNA-seq) technology was used to characterize the difference in liver fat metabolism between Hu sheep and Tibetan sheep. We identified 1179 differentially expressed genes (DEGs) (Q-value < 0.05) between the two sheep breeds, including 25 fat-metabolism-related genes. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, 16 pathways were significantly enriched (Q-value < 0.05), such as the proteasome, glutamatergic synapse, and oxidative phosphorylation pathways. In particular, one of these pathways was enriched to be associated with fat metabolism, namely the thermogenesis pathway, to which fat-metabolism-related genes such as ACSL1, ACSL4, ACSL5, CPT1A, CPT1C, SLC25A20, and FGF21 were enriched. Then, the expression levels of ACSL1, CPT1A, and FGF21 were verified in mRNA and protein levels via qRT-PCR and Western blot analysis between the two sheep breeds. The results showed that the mRNA and protein expression levels of these three genes were higher in the livers of Tibetan sheep than those of Hu sheep. The above genes are mainly related to FAs oxidation, involved in regulating the oxidation of liver FAs. So, this study suggested that Tibetan sheep liver has a greater FAs oxidation level than Hu sheep liver. In addition, the significant enrichment of fat-metabolism-related genes in the thermogenesis pathway appears to be related to plateau-adaptive thermogenesis in Tibetan sheep, which may indicate that liver- and fat-metabolism-related genes have an impact on adaptive thermogenesis.

Keywords: RNA-seq; fat metabolism; liver; sheep.

Grants and funding

CARS-38/the China Agriculture Research System of MOF and MARA