Association between PCR-SSCP of growth differentiation factor 9 gene and high prolificacy in Small Tail Han sheep
Association between PCR-SSCP of growth differentiation factor 9 gene and high prolificacy in Small Tail Han sheep
复制标题
生长分化因子9基因PCR-SSCP与小尾寒羊高繁殖力的关系
DOI：
10.1081/labt-200032582
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发表时间：
2004-01-01
影响因子：
3.7
通讯作者：
Fang, L
中科院分区：
文献类型：
--
作者：
Chu, MX;Li, BX;Fang, L
小尾寒羊是中国选育的优良地方绵羊品种，具有繁殖力高、排卵季节性强等显着特点。小尾寒羊产羔率平均为260%。生长分化因子9(GDF9)基因是影响小尾寒羊产羔数的候选基因，对早期卵泡的生长和分化起重要作用。采用聚合酶链式反应-单链构象多态性分析方法，检测了130只小尾寒羊母羊GDF9基因部分序列的遗传多态性。结果表明，两对引物均可检测到AA和AB两种基因型。小尾寒羊GDF9基因外显子1和外显子2的AA型频率分别为0.846和0.908，AB型频率分别为0.154和0.092，A等位基因频率分别为0.923和0.954，B等位基因频率分别为0.077和0.046。X_1(2)适合度检验结果表明，小尾寒羊GDF9基因外显子1和外显子2均处于Hardy-Weinberg平衡(p>；0.05)。小尾寒羊GDF9基因外显子1的第一胎产羔数和第二胎产羔数的最小二乘均值分别比AB型高0.30(P<0.0001)和0.77(P<0.05)。GDF9基因外显子2的片段对小尾寒羊第一胎和第二胎产羔数均无显著影响(p>；0.05)。绵羊的产羔数是低遗传性的，只在雌性身上表现出来，并在生命的较晚阶段表现出来。因此，获得遗传标记在选择计划中是有利的。
Small Tail Han sheep that has significant characteristics of high prolificacy and nonseasonal ovulatory activity is an excellent local sheep breed in P.R. China. The lambing percentage averaged 260% in Small Tail Han sheep. Growth differentiation factor 9 (GDF9) gene, which was essential for growth and differentiation of early ovarian follicles, was considered as a possible candidate gene for litter size in Small Tail Han sheep. The genetic polymorphism of a part of the GDF9 gene was detected in 130 ewes of Small Tail Han sheep by PCR-SSCP. The results indicated that there were two genotypes,(AA and AB) detected by two primer pairs. In both exon 1 and exon 2 of the GDF9 gene in Small Tail Han sheep, frequencies of AA genotype were 0.846 and 0.908, frequencies of AB genotype were 0.154 and 0.092, frequencies of A allele were 0.923 and 0.954, and frequencies of B allele were 0.077 and 0.046, respectively. The results of chi(2) fitness test indicated that both exon 1 and exon 2 of the GDF9 gene were in Hardy-Weinberg equilibrium (p > 0.05) in Small Tail Han sheep. Least squares means of litter size in the first and the second parity for genotype AA were 0.30 (p < 0.05) and 0.77 (p < 0.0001) more than those for genotype AB detected in exon 1 of the GDF9 gene in Small Tail Han sheep, respectively. Fragments detected in exon 2 of the GDF9 gene had no significant effect (p > 0.05) on litter size in both the first and the second parity in Small Tail Han sheep. Litter size in sheep is lowly heritable, expressed only in females, and manifested relatively late in life. Access to genetic markers would thus be advantageous in selection programs.