Meat Quality Of F₁ Generation Of Argali×oula Sheep And Association Analysis Of Gene Polymorphism Of UCP Family With Growth Traits Of Oula Sheep

In this study,the Argali and Oula sheep hybrid offspring（Hereinafter referred to as F₁generation of Argali×Oula sheep）and Oula sheep were used as research objects to conduct slaughter tests,measure slaughter performance,and UCP2 and UCP3 in the Uncoupling protein family related to animal growth and development were selected to study candidate genes for growth and development.The CDS regions of UCP2 and UCP3 genes were amplified and cloned by RT-PCR.The cloned products were sequenced and their characteristics were analyzed by bioinformatics.Genetic polymorphisms of UCP2 and UCP3 genes and their association with growth traits of Oula sheep were detected by PCR product sequencing.The main results of this study are as follows:1.In terms of slaughter performance,the pre-slaughter live weight of F₁generation of Argali×Oula sheep was significantly higher than that of Oula sheep（P<0.05）,there were no significant differences in carcass weight,slaughter rate,eye muscle area and other indicators（P>0.05）;In terms of meat quality,the water loss rate of Oula sheep was significantly higher than that of F₁generation of Argali×Oula sheep（P<0.05）;The amino acid contents of histidine and cysteine were significantly different（P<0.05）,and there was no significant difference in other amino acid contents between the two groups（P>0.05）;In terms of fatty acid content,The contents of monounsaturated fatty acids and polyunsaturated fatty acids in the F₁generation of Argali×Oula sheep were higher than those in Oula sheep（P>0.05）;In terms of the determination of flavor components,34 flavor components were found,with similar flavor components and little difference in content.2.The CDS region of UCP2 gene in F₁generation of Argali×Oula sheep was931 bp,with 7 open reading frames,encoding 309 amino acids.The CDS region of UCP3 gene was 937 bp,with 5 open reading frames,encoding 244 amino acids.The UCP2 protein of F₁generation of Argali×Oula sheep is a stable protein with a theoretical isoelectric point of 9.64,instability index of 36.27,half-life of 30 h and total average hydrophilicity of 0.109 and performance hydrophobicity.The UCP3protein of F₁generation of Argali×Oula sheep is an unstable protein with a theoretical isoelectric point of 9.25,an instability index of 44.80,a half-life of 30 h,and a total average hydrophilicity of-0.034 and show hydrophilicity.UCP2 and UCP3are both non-secretory proteins and have no signal peptides.UCP2 and UCP3 have no transmembrane helical structure,there were 26 phosphorylation sites in UCP2 and 23phosphorylation sites in UCP3.The secondary structure of UCP2 and UCP3 proteins mainly consists ofα-helix.At the same time,the subcellular localization revealed that UCP2 and UCP3 proteins mainly existed in the cytoplasm.3.Two SNPs loci were screened on UCP2 gene of Oula sheep,which were g.52130414 C>T and g.52130584 G>A,g.52130414 C>T produced TT,CT and CC three genotypes,g.52130584 G>A produced AA,AG and GG three genotypes.One SNP sites on UCP3 was identified as g.52157335 C>T,it produced CC,CT and TT three genotypes.The result of polymorphism analysis showed that the three SNPs sites were missense mutation sites,in moderate polymorphism and Conform to the hardy-Weinberg balance（P>0.05）.4.Association analysis between gene polymorphism and growth traits of Oula sheep showed that UCP2 gene g.52130414 C>T locus TT genotype body weight was significantly higher than CT genotype（P<0.05）;g.52130584 G>A,the body weight and body length of AA genotype were significantly higher than AG genotype and GG genotype（P<0.01）,AA and GG genotypes were significantly higher than AG genotypes（P<0.05）.UCP3 gene g.52157335 C>T,the weight of CC genotype was significantly higher than CT genotype（P<0.05）,TT genotype was significantly higher than CT genotype（P<0.05）.Genotype combination analysis of three polymorphic loci found that the body weight of D5 type was significantly higher than that of D1,D2and D3 type（P<0.01）.D5 body height was significantly higher than D3 type（P<0.05）.D5 type body oblique length was significantly higher than D2 type（P<0.01）,significantly higher than D1,D3,D4 type（P<0.05）.There was no significant difference in chest circumference among diplotypes（P>0.05）.This study evaluated the crossbreeding effect of the crosses between Argali and Oula sheep to provide a certain data basis for understanding and mastering their growth and development.Bioinformatics analysis of UCP2 and UCP3 genes can provide a scientific basis for exploring physiological functions of UCP2 and UCP3proteins in the future.UCP2 and UCP3 genes were used as candidate genetic markers affecting growth traits for breeding assisted selection,providing scientific basis for subsequent molecular breeding of Oula sheep.