崂山奶山羊LEP和STAT5a基因对泌乳和生长性状的影响

The Effect of LEP and STAT5a Genes on Milk and Growth Traits of Laoshan Dairy Goat

【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 (P＜0.01 or P＜0.05) on milk yield at 300 d, rump width of goats from farm and body height of goats from farm house-holds. Model and groups had a significant effect (P＜0.05) on milk traits and growth traits. There were two linked mutations on intron 9 of STAT5a gene, which had a significant effects on body length, heart girth (P＜0.01) and had no significant effect on milk traits (P＞0.05) 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.