Comprehensive transcriptome analysis of adipose tissue in the Bactrian camel reveals fore hump has more specific physiological functions in immune and endocrine systems

摘要

The unique hump structure of the Bactrian camel has helped it adapt to the harsh desert environment, and the adipose tissue contained in the hump is believed to play important roles in its survival. We used RNA sequencing to examine the transcriptome profiles of 7 adipose tissues of the fore hump, hind hump, subcutaneous, intermuscular, perihepatic, pericardial and peripheral tissues. A total of 4191 differentially expressed genes (DEGs) were identified between visceral fat (VF) and hump fat combined with subcutaneous fat (HS). Additionally, DEGs were also identified in the fore hump (FH), hind hump (HH) and subcutaneous fat (SC). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the identified DEGs showed that the hump has specialized immune and endocrine functions, in addition to its osmoregulatory roles. Further, DEGs involved in human diseases were significantly upregulated in visceral fat (VF), and DEGs associated with anti-hypertensive and anti-diabetic mechanisms were upregulated in HS. So HS seems to be more beneficial to health than visceral fat. Besides, fore hump has more immune and endocrine diverse genetic profile than subcutaneous fat. Thus, fore hump may be important for Bactrian camel's survival. Additional adaptation mechanisms should be further explored by obtaining more information on genetic and molecular mechanisms involved.