Based On Transcriptome Sequencing And Reduced-Representation Genome Sequencing Mining Genes And SNP Related To Reproductive Traits Of Xinjiang Local Sheep

The aim of this study is to screen for genes and SNP related to the initiation of puberty and litter size in sheep.Transcriptome sequencing and reduced-representation genome sequencing were used to analyze the genetic diversity and gene expression of different breeds of sheep,including Dolang sheep,Cele Black sheep,and Hetian sheep,and identify genes and SNP related to the puberty and little size.Transcriptome sequencing analysis revealed significant differences in the expression of genes such as GAMT,SOHLH1,DMC1,MACROD1,WNT2 B,SPIN1,CRH,TTR,and WISP1 in the hypothalamic tissue of Dolang sheep at different developmental stages,which may play a key role in regulating the puberty.TTR was one of the genes found to be differentially expressed,and we successfully cloned the TTR gene from the hypothalamic tissue of Dolang sheep and conducted further analysis.The c DNA sequence of the TTR gene was 610 bp,including 11 bp of 5’UTR,115 bp of 3’UTR,and 444 bp of CDS region.The amino acid sequence of TTR in Dolang sheep showed high homology with that of sheep,goats,and cattle,with similarities of99.32%,99.32%,and 93.20%,respectively,indicating a close relationship with sheep,goats,and cattle,and a relatively distant relationship with pigs,horses,and humans.Further investigation revealed that TTR was mainly expressed in the hypothalamus of Dolang sheep,with expression levels increasing and then decreasing prepuberty,puberty,and postpuberty.Moreover,TTR was found to inhibit the expression of Gn RH,suggesting its involvement in the regulation of the puberty in Dolang sheep.Reduced-representation genome sequencing analysis identified several SNP on PAK1 and ADCY1 genes that may be related to the puberty in sheep,while a SNP locus on the GNAQ gene may be related to little size.These findings provide new insights into the molecular mechanisms underlying the puberty and little size in sheep.In addition,we compared the genetic diversity of Cele Black sheep and Hetian sheep and found that Hetian sheep had higher genetic diversity than Cele Black sheep,which provides a reference for genetic improvement of sheep breeding.In summary,this study used transcriptome sequencing and reduced-representation genome sequencing to identify genes and SNP related to the puberty and little size in sheep,and conducted cloning,sequence analysis,tissue expression,and functional analysis of the TTR gene.Our findings suggest that TTR is one of the key genes involved in regulating the puberty in Dolang sheep and has an inhibitory effect on Gn RH expression.Furthermore,we identified several SNP related to the puberty and little size in sheep,providing a basis for further research on the molecular mechanisms underlying sheep breeding.This study’s rigorous methods and reliable results have important implications for genetic improvement and disease prevention in sheep breeding...