Identification And Comparative Analysis Of LincRNA Between Four High-altitude Vertebrates And Their Low-altitude Relatives

Animals living in high altitudes have evolved some typical physiological characteristics in order to adapt to the extreme environment of the plateau,such as larger heart output,heart and lung occupying a larger proportion of the whole body.In recent years,many studies have explained the high-altitude adaptation mechanism of plateau animals from physiological and genetic perspectives,but there are still few studies at the transcriptome level.Studies have shown that long intergenic non-coding RNA(lincRNA)plays an important role in some biological processes,but as of now,how lincRNA regulates gene expression and its mechanism of action in animal adaptation to plateau is poorly understood,especially in the comparative study of multi-species and multi-tissue lincRNA in high-altitude adaptation is even more blank.In order to study the adaptive mechanism at high altitude,transcriptome sequencing data were used to obtain transcriptome data of heart,liver,spleen,lung,kidney and skeletal muscle tissues of Tibetan sheep,Tibetan pigs,Tibetan chickens,Yaks and their low altitude relatives.The similarity of lincRNA participation mechanism in high altitude adaptation was explored.(1)A total of 144 samples of transcriptome data were detected,and 5197,4395,4802 and 3364 lincRNA were identified in sheep,chickens,cattle and pigs respectively.The results of sequence analysis and expression characteristics showed that compared with the gene encoding protein,the expression level of lincRNA was low,the tissue specificity was high,the number of variable splices and exons was small.The expression abundance(FPKM)of kidney tissue was higher.(2)The results of differential expression showed that the majority of lincRNA in sheep and cattle showed differential expression at high and low altitudes,followed by chickens and pigs.LincRNA was identified by correlation cluster analysis according to tissues,varieties and individuals.The results showed that the influence of tissues on lincRNA in the same species was significantly greater than that at elevation.The results of functional enrichment showed that these lincRNAs were extensively involved in the biological processes of liver lipid metabolism,heart muscle contraction,spleen immune response and inflammation.Bovine lincRNA BOSLINCTU17374 may be related to the lipid metabolism of bovine liver tissue.(3)Conservative analysis showed that the promoter region of conservative lincRNA sequence had higher repetitive element coverage ratio than that of protein coding sequence.The results of lincRNA sequence alignment among several species showed that chickens had lower correlation,fewer alignments and shorter sequences than the other two species(cattle and sheep).(4)The results of functional enrichment of conservative lincRNA showed that conservative lincRNA might regulate species adaptation to different altitudes by participating in cardiac muscle contraction and liver lipid metabolism.Homologous lincRNA was also associated with kidney development.At the same time,some conservative key lincRNA may be involved in myocardial contraction and lipid metabolism in heart and liver tissues,thus adapting to high altitude environment.LincRNA SUSLINCTU19187 and BOSLINCTU21058 are conserved in three species of artiodactyla,which may have the functions of regulating muscle contraction and lipid metabolism respectively.