微卫星座位多态性与两个肉用绵羊群体眼肌性状的关系

Relationship between the Polymorphisms of Microsatellites DNA and Longissimus dorsi Traits in Two Meat Sheep Populations

根据绵羊18号染色体遗传连锁图谱及相关报道,选择了可能与Carwell基因连锁或与眼肌性状有关的10个高度多态微卫星基因座,研究它们与眼肌性状的关系。应用非变性聚丙烯酰胺和复合银染技术分析了这些基因座的多态性,并分别对Dorset和Suffolk与新疆细毛羊级进杂交F2代两个肉羊群体的遗传特性进行了分析。应用最小二乘拟合线性模型分析了10个微卫星基因座多态性与超声波测量的眼肌性状(眼肌面积,眼肌厚度,眼肌宽度)的关系。结果表明:(1)Dorset群体中,BM3413基因座对眼肌厚度有显著影响(P<0.05),TGLA122基因座对眼肌宽度有显著影响(P<0.05),MCMA26基因座对眼肌厚度和宽度均有显著影响(P<0.05),从而影响眼肌面积;(2)Suffolk群体中,MCM38、CSSM18、ILSTS54和BM3413对眼肌厚度和宽度同时具有影响而显著或极显著地影响眼肌面积(P<0.05或P<0.01)。同时,本研究还发现了一些显著影响绵羊眼肌面积的最有利基因型:Dor-set群体中,微卫星基因座MCMA26的基因型FN(196 bp/222 bp)和基因型EM(192 bp/220 bp);Suffolk群体中,微卫星基因座CSSM18的基因型AE(124 bp/134 bp),ILSTS54的基因型AD(130 bp/148 bp)和CD(134 bp/148bp)以及BM3413的基因型BF(190 bp/232 bp)。综合分析表明:(1)微卫星MCMA26-CSSM18区域可能为Carwell基因的存在位点,而BM3413可能是一个除Callipyge与Carwell之外新的影响绵羊后臀和眼肌性状QTL或基因的存在区域;(2)本研究发现的一些最有利基因型在今后的肉羊选育中有望作为相应群体早期辅助选择的标记基因型。

To investigate the relationship between the polymorphisms of the microsatellites and the Longissirnus dorsi （L. dorsi） traits, ten highly polymorphic microsatellite loci which probably be linked with the Carwell gene were selected from the genetic linkage map of chromosome 18 in sheep. The polymorphisms of these microsatellites were detected, and the genetic character was analysed in two grading crossing sheep group（F2 from Dorset ♂ and Suffolk ♂× Xinjiang fine wool sheep♀ ,respectively ） with nondenaturing polyacrylamide gel electrophoresis by multiplex silver staining. Results showed that there were differences for genetic parameters between the two meat sheep groups among these loci. The effect of these loci on L. dorsi traits were analyzed in a generalized linear model（GLM）. Results indicated that ： （1） The effect of BM3413 on thickness of L. dorsi reached a significant level at P〈0.05 , and TGLA122 had a significant effect on width of L. dorsi （P〈0. 05） , respectively; The locus MCMA26 had a significant impact on thickness, width and area of L. dorsi traits （P〈0.05） in the Dorset group, respectively. While the other loci（ILSTS54, TGLA337, HH47, TGLA122, BP33, MUM38 and CSSM18 ） had no impact on theL. dorsitraits （P〉0.05） in the same group; （2） In the Suffolk population, thelo ci of MUM38, CSSM18, ILSTS54 and BM3413 each had a significant impact on all the three L. dorsi traits simultaneously （P〈0.05 or P〈0.01 ）; And the other 6 loci（ TGLA337, HH47, TGLA122, BP33, OB2 and MCMA26 ） had no effect （P〉0.05） in the same group . We also found that, 196 bp/222 bp and 192 bp/220 bp at MCMA26 were the most favourable genotypes for area ofL. dorsi in the Dorset group; 124 bp/134 bpat CSSM18, 130 bp/148 bpand 134 bp/ 148 bp at ILSTS54 , 190 bp/232 bp at BM3413 were the most favourable genotypes for area of L. dorsi in the Suffolk group. Two conclusions were drew ： （1） The Carmell gene probably located in the region of MCMA26- CSSM18, and there may be a new gene or QTI.s （quantitative trait loci） flanking the locus BM3413; （2） The most favourable genotypes we found may be regarded as the candidate-loci for the marker -assisted selection or marker-assisted breeding in the merit meat sheep on early period.