崂山奶山羊LEP和STAT5a基因对泌乳和生长性状的影响

摘要

[目的]探讨JAK-STAT通路中瘦素（Leptin，LEP）和信号转导子和转录激活子5a（signal transducers and activators of transcription，STAT5a）基因在崂山奶山羊群体中的遗传变异、交互作用及与生产性状的关联性。[方法]以174只崂山奶山羊泌乳母羊为实验群体，其中89只来自种羊场，有完整的产奶量记录；85只来自育种户。利用DNA混池测序和候选基因直接测序技术检测LEP基因外显子2、外显子3和STAT5a基因外显子10、外显子16在该群体中的多态性，并采用最小二乘法分析了多态性位点与乳成分、校正产奶量、生长性状的关联效应。[结果]在所研究的群体中，LEP基因外显子2、3和STAT5a基因外显子10、16上均不存在多态性。LEP基因内含子2上存在一个 A→G 的单核苷酸替换，对于泌乳和生长性状而言，模型和场别效应均达到显著水平，该位点对育种场中校正产奶量和尻宽、育种户中体高有显著(P＜0.05)或极显著(P＜0.01)影响；STAT5a基因内含子9上存在 A→G 的单核苷酸替换和 T→C 的单核苷酸替换，这两个突变为连锁突变，对泌乳性状没有显著影响(P＞0.05)，对整个群体体长和胸围有显著(P＜0.05)影响，对育种户胸围有极显著(P＜0.01)影响。[结论]在崂山奶山羊中发现候选基因LEP和STAT5a存在多态性，相互之间没有交互作用，L393位点对育种场中校正产奶量和尻宽、育种户中体高有显著效应，S163/S206位点对整个群体的体重、体长和胸围，对育种户胸围有显著效应。因此，LEP和STAT5a基因可以作为崂山奶山羊产奶量及部分生长性状的遗传标记。%[Objective]The objective of this experiment is to explore the genetic variation and interaction of LEP and STAT5a genes in Laoshan dairy goat and its association with production traits. [Method] There are 174 lactating ewes of Laoshan dairy goats, of which 89 goats having complete records of milk yield are from dairy goat breeding farm and 84 goats are from farm house-holds.DNA pooling technology and candidate genes by direct sequencing technology were used to detect the polymorphisms in exon 2, exon 3 of LEP gene and exon 10, exon 16 of STAT5a gene. The method of least squares was used to analyze the correlation effects of polymorphic loci associated with milk composition, milk yield at 300 d and growth traits.[Result]There was no polymorphism in exon 2,3 of LEP gene and in exon 10,16 of STAT5a gene. A mutation from A to G was found in intron 2 of LEP gene, which had a significant effects (P0.05) in all groups. It had a significant effects on heart girth (P<0.01) of goats from farm house-holds.[Conclusion]Results of this study showed that the candidate genes LEP and STAT5a have polymorphisms in Laoshan dairy goat. There was no significant interaction between the two genes. The locus of L393 has a significant effects on milk yield at 300 d and rump width of goats from breeding farm, and on body height of goats from farm house-holds. The loci of S163/S206 have a significant effect on body weight, body length and heart girth of all groups, and on heart girth of goats from farm house-holds. So they could provide valuable genetic markers for milk yield and some growth traits of Laoshan dairy goat.