山羊FGF18基因变异及其对羊绒性状的影响

Variation of FGF18 Gene in Goats and Its Effect on Cashmere Traits

为了研究FGF18基因在山羊中的多态性以及对羊绒性状的影响,通过PCR-SSCP结合测序的方法对FGF18基因3个区域(Exon 3、Exon 4和Exon 5)在3个山羊群体(陇东绒山羊、柴达木绒山羊、中卫山羊)中的多态性进行检测,并分析基因多态性与陇东绒山羊羊绒性状的关联性。结果显示,FGF18基因在3个山羊群体中均较保守,只在Exon 5发现一个同义突变(c.498T>C)。c.498T>C位点对应的3种基因型EE、EF和FF在3个群体中均被检测到,且均处于Hardy-Weinberg平衡。等位基因E在3个群体中均为优势等位基因;陇东绒山羊、柴达木绒山羊和中卫山羊的优势基因型分别为EF、EE和EF。FF型陇东绒山羊的产绒量和绒层高度显著高于EE型和EF型山羊(P<0.05)。综上,山羊FGF18基因呈中度多态,c.498T>C位点与陇东绒山羊的产绒量和绒层高度呈显著相关,提示若以这2个性状为选育目标,FGF18基因可以作为分子改良的候选基因。

In order to study the polymorphism of FGF18 gene in goats and its effect on some cashmere traits,PCR-SSCP combined sequencing method were used to analyze three regions(Exon 3,Exon 4 and Exon 5)of FGF18 gene in three goat breeds(Longdong cashmere goat,Chaidamu cashmere goat,and Zhongwei goat),then the association between gene polymorphism and variation of Longdong cashmere goat traits was analyzed.The results showed that FGF18 gene was conserved among the three goat breeds,and only one synonymous mutation was found in Exon 5(c.498 T>C).Three genotypes EE,EF and FF caused by c.498 T>C locus were detected in all three goat breeds,and the distribution in the three goat breeds was at Hardy-Weinberg equilibrium with respect to this SNP.Allele E was the dominant allele in all three goat breeds;the dominant genotypes of Longdong cashmere goats,Chaidamu cashmere goats and Zhongwei goats were EF,EE and EF,respectively.The cashmere yield and height of Longdong cashmere goats with FF genotype goats were significantly higher than those goats with EE genotype and EF genotype(P<0.05).The results showed that the FGF18 gene was moderately polymorphic in the three goat populations and the c.498 T>C site was significantly associated with the cashmere yield and the height of down layer of the Longdong cashmere goats.It was suggested that FGF18 gene can be used as a candidate gene for molecular improvement when these two traits are used as the breeding targets.