GSE126082
Comparative transcriptomic and proteomic analyses provide insights into functional genes for hypoxic adaptation in embryos of Tibetan chickens
Background/Aims: Tibetan chickens, a unique plateau breed, have good performances to adapt to high-altitude hypoxic environments. A number of positively selected genes have been reported in Tibetan chickens; however, the mechanisms of gene expression for hypoxia adaptation are not fully understood. Methods: Eggs from Tibetan (TC) and Chahua (CH) chickens were incubated under hypoxic and normoxic conditions, and vessel density index (VDI) in the chorioallantoic membrane (CAM) of embryos was measured. Meanwhile, Transcriptomic and proteomic analyses of CAM tissues were performed in TC and CH embryos under hypoxic incubation using RNA-seq and iTRAQ. Results: We found that the vessel density index (VDI) in CAM of TCs was lower than in CHs under hypoxia incubation.  In the transcriptomic and proteomic analyses, 160 differentially expressed genes (DEGs) and 387 differentially expressed proteins (DEPs) that were mainly enriched in angiogenesis, vasculature development, blood vessel morphogenesis, blood circulation, renin-angiotensin system, and HIF-1 and VEGF signaling pathways. Twenty-six genes involved in angiogenesis and blood circulation, two genes involved in ion transport, and six genes that regulated energy metabolism were identified as candidate functional genes in regulating hypoxic adaption of chicken embryos. Conclusion: Combination of transcriptomic and proteomic data revealed several key candidate regulators and pathways that might play high-priority roles in the hypoxic adaptation of Tibetan chickens by regulating angiogenesis and promoting blood circulation, thus explaining the blunt responses to hypoxic conditions on CAM angiogenesis in Tibetan chicken embryos. This research provided insights into the molecular mechanism of hypoxia adaptation in Tibetan chickens. Overall design: Chorioallantoic membrane (CAM) of embryos mRNA profiles of 11-day old Tibetan chickens (TCs) and Chahua chickens (CHs) were generated by deep sequencing, in triplicate, using Illumina HiSeq 4000 platform.