Study On The Relationships Between Polymorphisms Of Chicken Pituitary Specific Transcription Factor 1 Gene And Slaughter Traits

Prolactin,growth hormone and thyroid-stimulating hormone beta subunit,which has important physiologic function,was secreted by anterior pituitary.The three hormones regulate the egg laying,growth and development,immune response of poultry.Nevertheless,Pituitary specific transcription factor 1(pit-1) gene can regulate and control the express of aforesaid three hormones in chickens,accordingly effect the performance traits in molecular level.This study was conducted to detect polymorphisms in intron 1,3 and 4 of chicken Pit-1,among 6 breeds and to determine the associations between its genotypes and carcass traits in some native chicken population by using the PCR-RFLP technique.The results of PCR-RFLP technique shows that there has mutational site in Mountainous Black-bone chicken(SD),Xinghua chicken(T),Huxu chicken(H),Q ingyuan Ma chicken(Q)and Xiayan chicken(S) in the intronl.The sequencing result showed that mutation is C/T.The results by LSM(least square means) analysis and significant test showed that,except for leg weight(LW),abdominal fat weight(AW),carcass percentage(CP),halfeviscerate percentage(HP),eviscerate percentage(EP) had no significant difference(P＞0.05),the other traits had signifi cant difference with this mutation(P＜0.05).The results of PCR-RFLP technique shows that there has mutational site in Xinghua chicken(T) and Xiayan chicken(S) in the intron3.The sequencing re suit showed that mutation is C/T.The results by LSM(least square means) a nalysis and significant test showed that,Body weight(OW),Carcass Weight(CW) ,Halfeviscerate Weight(HW),Eviscerate weight(EW),breast percentage(BP),leg p ercentage(LP),Halfeviscerate percentage(HP),Eviscerate percentage(EP) had s ignificant difference with this mutation(P＜0.05),but no differences were found for other traits(P＞0.05)。The results of PCR-RFLP technique shows that there has mutational site in Xinghua chicken(T),Huxu chicken(H),Qingyuan Ma chieken(Q)and Xiayan chic ken(S),in the intron4.The sequencing result showed that mutation is G/C.The re suits by LSM(least square means)analysis and significant test showed that,no differences were found for abdominal fat weight(AW),carcass percentage(CP), halfeviseerate percentage(HP)(P＞0.05),the other traits had found significant differe nee(P＜0.05).Haplotypes constructed based on 3 SNP and their frequencies in 6 populations are shown that eight haplotypes were identified in 166 chickens,in which the 3 most abundant ones,designated H2(GEF),H6(HEF) and H8(HTF),the frequency exceed 10%.The mixed model analysis indicated that,significantly difference of H1H1 diplotype were observed for body weight(OW),carcass weight(CW),halfeviscerate weight(HW),eviscerate weight(EW)as well as H1H4 for carcass weight(CW),leg weight(LW),breast weight(BW)and leg percentage(LP).Results also showed that the H1H2 and H1H6 diplotype had a significantly and suggestively dominant effects on leg percentage(LP).In addition,we also discovered that H1H5 had positive effect on eviscerate weight(EW).This study could offer some advises on the effeetion of chicken pit-1 gene single nucleotide polymorphisms in intron with carcass traits,and provid evidence for maker assisted selection(MAS).