Tissue Expression,Polymorphisms Of STAT5A And THRSP Gene And Their Effect On Milk And Meat Quality Traits Of Yak

Signal transduction and activator of transcription 5A?STAT5A?as a specific transcription factor that regulates lactoprotein expression in breast,plays an important role in milk production traits.Thyroid hormone responsive spot 14?THRSP?as an important regulated gene of lipid synthesis,plays an important role in lipogenesis.In this study,we investigated relative expression of STAT5A and THRSP gene by real-time quantitative PCR in Gannan yak,varitations of STAT5A and THRSP gene were identified by DNA pool sequencing and genetic diversity of Gannan Yak,Tianzhu white yak,Qinghai yak,Tibetan yak and wild blood yak were analysied by Polymerase Chain Reaction-Single Strand Conformation Polymorphism?PCR-SSCP?.The effects of STAT5A and THRSP gene variations on milk quality traits and the effects of THRSP gene variations on carcass and meat quality traits were further analyzed.The results showed:1.The relative expressions of STAT5A and THRSP gene were different in 12 tissues of Gannan yak.?1?The higher expression of STAT5A gene was found in mammary gland?P<0.05?.?2?The expression of THRSP gene was significant in subcutaneous fat heart,liver,breast and longissimus dorsi,and the lower expression in abdomen,lung and large intestine.2.The STAT5A and THRSP gene had polymorphisms in yak.?1?Three alleles A₁,B₁,C₁and two SNPs?C.376-15 C>T and C.550+62 T>C?were detected in intron 3 of STAT5A gene,and the polymorphism of 5 yak populations was lower and PIC value was 0.0939⁰.2387.Two alleles A₂,B₂ and a synonymous variation?c.606 G>A?were detected in exon 5 of STAT5A,the yak populations presented moderate polymorphism with PIC value in range of0.2560⁰.3571.Two alleles A₃,B₃ and two SNPs?c.1191+4 C>T and c.1194+81 T>C?were detected in intron 8 of STAT5A,the allele B₃ existed in the Gannan yak population,and its frequency was<5%.Alleles A₄,B₄ and SNP?c.1282-38 T>C?was detected in intron 9 of STAT5A,the Qinghai yak and Tibetan yak presented low polymorphism with PIC value in range of 0.1889⁰.2358.The remain yak populations presented moderately polymorphic with PIC value in range of 0.2583⁰.3488;Alleles A₅,B₅ and SNP?c.*231 G>A?were detected in3'UTR of STAT5A,all populations presented moderate polymorphism with PIC value in range of 0.3641⁰.3748.?2?Two alleles A,B and a nonsynonymous variation?c.131 G>A?were detected in exon 1 of THRSP,which lead to the conversion of the p.Arg 44 Gln.The yak populations were low polymorphism with PIC value in range of 0.0270⁰.1401.3.The association analysis showed that the variations in STAT5A gene affected the milk quality traits in different parities of Gannan yak.The variation in THRSP gene had no effect on the milk quality traits,which affected the carcass weight in different age groups of Gannan yak.?1?In intron 3-intron 4 of STAT5A gene,individuals with genotype A₁A₁ in third parity yak had significantly higher milk protein rate than those with other genotyges?P<0.05?;In exon 5-intron 5 of STAT5A gene,individuals with genotype B₂B₂ in thrid parity yak had significantly higher milk fat rate and total solids percentage than those with other genotyges?P<0.05?.The individuals with deletion allele A₂ and carrying allele B₂ had significantly higher milk fat percentage and total solid percentage in third parity Gannan yak?P<0.05?.In intron 9-exon 10 of STAT5A gene,individuals with genotype A₄B₄ had significantly higher milk fat rate and total solids percentage in second yak than those with other genotyges?P<0.05?.In 3'UTR of STAT5A gene,individuals with genotype A₅A₅ had significantly higher milk protein rate in first parity than those with other genotyges?P<0.05?.?2?In exon 1 of THRSP gene,individuals with genotype AB had significantly higher carcass weight in 5 years old yak than those with other genotyges.