Cloning Of GHSR Gene And Its Correlation With Growth Performance In Lanzhou Fat-Tailed Sheep

Growth hormone secretagogue receptor(GHSR)is a polypeptide consisting of 366 amino acids,belonging to the G-protein coupled receptor(GPCR)family,consisting of two exons and one intron.Has 7 transmembrane structures.GHSR plays an important role in the release of growth hormone from the anterior pituitary gland and regulates the growth and development of the body.In this study,the full-length GHSR gene of Lanzhou fat-tail sheep was cloned by RT-PCR and analyzed by bioinformatics.Polymorphism in sheep populations and its correlation with growth traits such as body weight and body length,qRT-PCR was used to detect the expression level of GHSR gene in different tissues of small-tailed Han sheep and Lanzhou fat-tailed sheep,with a view to the molecule of sheep Breeding and breed selection provide a theoretical basis.The findings are as follows:1.Cloning and Bioinformatics Analysis of GHSR Gene in Lanzhou Fat Tail SheepLanzhou fat-tailed sheep GHSR gene nucleotide sequence coding region is 1101 bp in length and encodes 366 amino acids.It is the same as sheep(Lambo sheep),cattle,wild boar,horse,white rhinoceros,rat,mouse,human,and gorilla.The source is 99.64%,95.82%,91.11%,91.73%,91.55%,90.83%,89.92%,89.65%,and 89.83%,and the genes are more conservative.Lanzhou fat-tail sheep GHSR protein sequence has 7 transmembrane Alpha helix and no signal peptide.2.Association analysis of GHSR gene polymorphisms and growth traits in different sheep breedsThere is a 24 bp indel mutation in the first intron of the GHSR gene,and there are three genotypes of AA,AB,and BB in all three sheep breeds.The polymorphism at this site is related to the growth of eight sheep in three species.Correlation analysis of trait indicators showed that the body height and cross-section height of AB genotype in Lanzhou fat-tail sheep were significantly higher than other genotypes(P <0.05).The individual breast width and body height of the small-tailed Han sheep with AB genotype was significantly higher than other genotypes(P <0.05).The body height and cross-section height of individuals with AA genotype were significantly higher than those with BB genotype(P <0.05).Individual body oblique length and body weight were significantly higher than AA genotype(P <0.05),and individual body height of BB genotype was significantly lower than other genotypes(P <0.05).3.Analysis of GHSR gene expression in tissues of Lanzhou fat-tail sheep and small-tail cold sheepThe GHSR gene is highest expressed in the brain tissue of Lanzhou fat-tail sheep,followed by the spleen,intestine,lung and heart,and the least expressed in muscle and testis.The GHSR gene is highest expressed in the brain tissue of small-tailed han sheep,followed by It is the lung,intestinal tissue,and spleen,and it is the least expressed in muscle and testis.The GHSR gene is mainly expressed in the brain tissue of two sheep.In lung tissue,the expression of small-tailed han sheep is higher than that of Lanzhou fat-tailed sheep.In both species,the expression levels were similar.Conclusion: The protein expressed by the GHSR gene of Lanzhou fat-tail sheep is a transmembrane protein and not a secreted protein.The 24 bp indel mutation found on the first intron of the GHSR gene is related to the growth traits of sheep.Affects the body height and weight of sheep.The high expression of this gene in sheep's brain indicates that this gene mainly plays its biological function in the brain.