| 摘要: |
| 【目的】 比较滩羊、蒙古羊和小尾寒羊INHA基因的多态性，分析不同基因型对产羔数的影响，为绵羊繁殖力标记的辅助选择提供理论依据。【方法】 利用PCR-SSCP方法检测和分析3个绵羊品种INHA 基因的多态性，通过最小二乘分析方法研究不同基因型对产羔数的影响。【结果】 （1）滩羊和蒙古羊INHA基因在5′调控区282核苷酸处发生1处A→G突变（P1位点），在第2外显子的第470核苷酸处发生1处A→T突变（P2位点），3个绵羊品种在第2外显子第903核苷酸处发生G→A突变（P3位点）。（2）滩羊、蒙古羊和小尾寒羊P1位点C、D基因频率分别为0.840和0.160，0.852和0.148及0.162和0.838，均处于中度多态；P2位点E、F基因频率分别为0.784和0.216，0.787和0.213及1.000和0.000，滩羊和蒙古羊在该位点均处于中度多态；引物P3扩增片段中，滩羊和蒙古羊表现为A、B和C 3种单倍体基因型，而小尾寒羊仅表现出A和B 2种基因型。滩羊、蒙古羊和小尾寒羊的A、B、C基因型频率分别为0.136，0.037和0.147；0.800，0.926和0.853及0.064，0.037和0.000， B基因在3品种中均为优势基因型。（3）P1 位点DD型小尾寒羊产羔数较CD型提高0.636只，CD型滩羊产羔数较CC型提高0.332只，差异均显著（P<0.05），CD型蒙古羊产羔数较CC型有提高的趋势；P2 位点EF型滩羊产羔数较EE型降低0.387只，差异显著（P<0.05），EF型蒙古羊产羔数较EE型提高0.053只，差异不显著（P>0.05）；P3 位点，滩羊B基因型平均产羔数较A、C基因型分别多0.215只和0.200只，蒙古羊B基因型平均产羔数较C基因型多0.250只，小尾寒羊B基因型平均产羔数较A基因型多0.620只，差异均显著（P<0.05）。【结论】 3个绵羊群体在INHA基因P1 、P2 位点均表现一定的多态性；滩羊和蒙古羊P2 位点可能为控制产羔数的“不利”突变位点，3个绵羊群体INHA基因P1 、P3位点可能为控制产羔数的“有利”突变位点。 |
| 关键词: 滩羊 蒙古羊 小尾寒羊 INHA基因 产羔数 |
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| 基金项目:宁夏回族自治区畜牧工作站“宁夏滩羊选育及养殖配套技术与示范推广”资助项目 |
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| Genetic polymorphism of INHA gene and its effect on litter size in three sheep breeds |
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TIAN Xiu-e,SUN Hong-xia,WANG Yong-jun
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| Abstract: |
| 【Objective】 The research compared the gene polymorphism of INHA gene in Tan sheep,Mongolian sheep and Small Tailed Han sheep,analyzed the effect of different genotypes on the litter size,which will provide a theoretical basis for marker-assisted selection for high prolificacy in sheep.【Method】 The gene polymorphism of INHA gene was measured by PCR-SSCP and the effect of different genotypes on litter size was analyzed by least squares mean.【Result】 (1) There was one single nucleotide mutation (A→G) at promoter 282 nucleotide of P1 locus in three sheep breeds,A→T mutation at the second exon 470 nucleotide of P2 locus,G→A mutation at the second exon 903 nucleotide of P3 locus.(2) For P1 locus,gene frequencies were 0.840 and 0.160,0.852 and 0.148 as so as 0.162 and 0.838 of C and D genes in Tan sheep,Mongolian sheep and Small Tailed Han sheep respectively,showing moderate polymorphic.For P2 locus,gene frequencies were 0.784 and 0.216,0.787 and 0.213 as so as 1.000 and 0.000 of E and F gene respectively in three sheep;Tan sheep and Mongolian sheep showed moderate polymorphic.For P3 locus,Tan sheep and Mongolian sheep showed three haploid genotype A,B,C resp.Genotype frequencies were 0.136 and 0.037,0.800 and 0.926,0.064 and 0.037.Small Tailed Han sheep showed two haploid genotype A and B,genotype frequencies were 0.147 and 0.853.Haploid genotype B was the dominant one of the three breeds.(3) For P1 locus,the average litter size of Small Tailed Han sheep with genotype DD was 0.636 lambs (P<0.05) more than CD genotype,and genotype was 0.332 lambs (P<0.05) CD more than CC of Tan sheep,CD genotype tended to increase litter size compared with CC genotype.For P2 locus,the average litter size of Tan sheep with genotype EF was 0.387 lambs (P<0.05) less than EE genotype;on the contrary,genotype EF had 0.053 lambs (P>0.05) more than EE of Mongolian sheep.For P3 locus,the average litter size of Small Tailed Han sheep with genotype B was 0.620 lambs (P<0.05) more than A genotype,genotypes B had 0.215,0.200 lambs (P<0.05) more than A and C genotype of Tan sheep,genotypes B had 0.250 lambs (P<0.05) more than C genotype of Mongolian sheep.【Conclusion】 P1,P2 locus show some polymorphism of INHA gene in three sheep breeds. P2 mutation locus is possible adverse mutation of the litter size in Tan sheep and Mongolian sheep,P1 and P3 mutation locus are possible benefit mutation of the litter size in three sheep breeds. |
| Key words: Tan sheep Mongolian sheep Small Tailed Han sheep INHA gene litter size |
