农业生物技术学报2017，Vol.25Issue(6)：893-900,8.DOI:10.3969/j.issn.1674-7968.2017.06.004
绵羊KITLG基因的表达及其多态性与产羔性状关联分析
Expression and Polymorphisms of KITLG Gene and Their Association with Litter Size in Sheep (Ovis aries)
摘要
Abstract
Reproductive performance is an important economic trait in sheep (Ovis aries).The study of its molecular mechanism is also extremely important.Reproductive performance of sheep is regulated by the hypothalamic-pituitary-gonad reproductive axis,and is also controlled by many growth factors.KITLG acting as ligand of KIT (KIT LIGAND,KL or KitL),as an important growth regulation factor,plays a key role in follicular development.The current study aimed to analyze the expression of KITLG gene and SNPs as well as their association with litter size in sheep,and to offer a reference data for the candidate gene research of reproduction trait in sheep.Therefore,Real time-PCR was conducted to investigate the expression patterns of KITLG gene in hypothalamus,pituitary,ovary,heart,muscle,lung,kidney,liver,spleen,duodenum,fat and rumen tissues of Hu sheep,and restriction fragment length polymorphism (RFLP) technologies were carried out to screen SNPs and analyze their association with litter size in sheep population of Hu sheep and Small tail Han sheep.The results revealed that KITLG gene expressed in heart,liver,spleen,lung,kidney,rumen,duodenum,muscle,fat,hypothalamus,pituitary,and the expression in ovary was high.According to PCRRFLP technologies,two polymorphisms g.38473C＞T and g.47468C＞T2 were identified in intron 2 and 5 ofKITLG gene respectively.In g.38473C＞T locus,two genotypes,CC and CT were found in both Hu sheep and Small tail Han sheep.Of them,CC was the dominant genotype,and C was the dominant allele.In addition,the homozygosity (Ho),heterozygosity (He),effective allele number (Ne),polymorphic information content (PIC) were 0.89,0.11,1.31 and 0.11 for Hu sheep,and were 0.80,0.20,1.10 and 0.16 for Small tail Han sheep,respectively.The x2 test indicated that Small tail Han sheep and Hu sheep populations were in Hardy-Weinberg equilibrium.Same as g.38473C＞T locus,two genotypes,CT and TT were identified in g.47468C＞T locus in both Hu sheep and Small tail Han sheep.Of which,TT was the dominant genotype,and T was the dominant allele.The Ho,He,Ne,PIC were 0.95,0.05,1.06,0.05 for Hu sheep,and were 0.91,0.09,1.10 and 0.09 for Small tail Han sheep,respectively.The x2 test indicated that Small tail Han sheep population and Hu sheep were all in Hardy-Weinberg equilibrium.The association analysis of polymorphisms in KITLG gene with litter size revealed that g.47468C＞T was significantly correlated with litter size in Hu sheep and Small tail Han sheep (P＜0.05).In summary,this study indicated that expression of KITLG gene in ovary was high.SNP (g.47468C＞T) of KITLG gene was associated with litter size in Small tail Han sheep,and this gene could be used as a candidate gene for litter size selection at early stage of growth.This study provides a scientific basis for searching molecular markers associated with reproductive traits of the sheep,and setting breeding strategies,as well as improving the production performance of sheep.Compared with traditional breeding methods of sheep,the reaching results can also be used as a markerassisted selection to greatly improve the breeding speed,and to achieve greater genetic progress in sheep.关键词
KITLG基因/单核苷酸多态性/产羔数/基因表达/绵羊Key words
KITLG gene/Single nucleotide polymorphisms/Litter size/Gene expression/Sheep分类
农业科技引用本文复制引用
张军霞,李发弟,喇永富,乐祥鹏,王维民,谢云龙,王志兰,张娜娜,胡瑞雪,孙武,邓颖..绵羊KITLG基因的表达及其多态性与产羔性状关联分析[J].农业生物技术学报,2017,25(6):893-900,8.基金项目
国家自然科学基金项目(No.31472072)和国家肉羊现代肉羊产业技术体系建设专项(CARS-39) （No.31472072）
