蛋鸡与肉鸡卵巢组织基因差异表达与产蛋数杂种优势的相关性研究

Relationship between Differential Gene Expression Patterns in Chicken Ovary and Heterosis of Egg Number in a Chicken Diallel Cross

以白莱航蛋鸡(AA)、农大褐蛋鸡(DD)和白洛克肉鸡(EE)3 个纯系及其正反杂交产生的 6 个杂交系为试验材料,应用mRNA差异显示技术,研究了产蛋高峰期(32 周龄)纯种鸡与正反交杂种群卵巢组织的基因差异表达,及其差异表达模式与32周龄产蛋数的杂种优势率的相关性。结果:24 种引物组合共扩增出 1 572 条带,其中能够重现的有1 126条,重现率为71.63%。在6个正反杂交群中检测到7类基因差异表达模式:P1杂种超强表达(22 .29%);P2杂种特异表达(9. 84%); P3 杂种减弱表达(9. 85%); P4 杂种沉默(3. 42%); P5 单亲特异表达(22. 91%);P6单亲显性表达(25.74%);P7共显性表达(5.95%)。相关性分析表明:32 周龄产蛋数的杂种优势率与杂种特异型表达模式(P2)呈显著的负相关(P<0 05);而与杂种减弱型表达模式呈显著的正相关(P<0. 05)。这一研究结果为探索鸡的产蛋性状杂种优势的分子遗传机理奠定了基础,同时探讨了差异表达基因与杂种优势的关系。

In order to understand the molecular basis of chicken heterosis, mRNA differential display method was used to analyze the differential gene expression of ovary tissue between hybrids and their parental lines in a 3×3 diallel cross involving 3 chicken breeds, which were White Plymouth Rock(EE), CAU Brown(DD)and White Leghorn(AA). Only bands that can be repeated in duplicate DDRT-PCR amplification were used for statistic analysis. Our results showed that differences of gene expression between hybrids and their parent lines were very obvious both in quantitative and qualitative. By using 24 pairs of primer combination, a total of 1 572 bands were displayed, and 71.63 (1 126 out of 1 572) can be repeated. The average differential expression band of 6 hybrids is 169.67(15.07), which were grouped into seven types of differential expression patterns: Over-expression of parental fragements in hybrids (P1=22.29),hybrid-specific expressed fragements (P2=9.84),Under-expression of parental fragements in hybrids (P3=9.85),hybrid-absence expressed fragements (P4=3.42),parent-specific expressed fragements (P5=22.91),Dominant expression fragements of single parent in hybrids (P6=25.74), Co-dominance expressed fragements (P7=5.95). Correlation analysis indicated that there are significant negative correlation or significant correlation between the pattern of P2 or the pattern of P3 and heterosis percentage of 32 week-old egg number, which indicates that hybrid-specific expressed fragements or Under-expression of parental fragements in hybrids are likely to restain or strengthen the heterosis forming of 32 week-old egg number.