生长激素基因多态性与山羊体重性状的关系

Relationship Between Polymorphism of Growth Hormone Gene and Production Traits in Goats

以鲁北白山羊、波尔山羊以及波尔山羊与鲁北白山羊的杂交一代、回交一代共计224只山羊为材料,根据山羊生长激素基因5′调控区的序列(GenBank登录号:D00476)设计两对引物,用PCRSSCP法进行多态性分析。多态性片段的纯合基因型经克隆测序,发现共有5处突变。对突变位点产生的不同基因型与体重、体尺性状进行分析表明:第一对引物扩增片段波尔山羊AA型个体的初生重、周岁重显著高于BB型和AB型(P<0.05);杂交一代中断奶重、周岁重也以AA型偏高,但不同基因型间的差异均不显著(P>0.05);而鲁北白山羊BB基因型的体重相对于另外两种基因型的偏低,且断奶重的差异达到显著水平(P<0.05)。第二对引物扩增片段不同基因型对体重、体尺没有显著影响。由此初步推断生长激素基因可能是影响山羊体重性状的主基因或与主基因相连锁,可以用该位点对山羊体重性状进行标记辅助选择。

Growth hormone(GH) plays an important role in animal growth and development,and the growth hormone gene can be considered as a candidate gene for studying the weight in goats.The function of GH gene has been intensively studied in cattle and pigs,while in goats the study is still rare .In this paper 224 goats including LuBei White goat,Boer goat,hybrid generation 1 and backcross generation 1 of Boer goat and LuBei White goat were used.Two pairs of primers for 5′region of GH gene were designed according to the database of goat genomic sequence(Accession No.D00476)and polymorphisms were detected by PCR SSCP.Homozygotes of the polymorphic fragment were cloned and sequenced.The result showed that there were five substitution mutations in the two fragments.Statistical analysis showed that in the fragment amplificated by the first pair of primers, AA genotype had significant higher birth weight and weight of one year old than BB and AB genotyps in Boer goats( P <0 05).In hybrid generation 1 AA genotype also had higher birth weight and weight of one year old in significantly.While in LuBei White goats BB genotype had lower weight and the weaning weight was significant lower than the other two genotypes( P <0 05).In the fragment amplificated by the second pair of primers there was no significant difference among different genotypes.From these results we can preliminarily draw the conclusion that GH gene may be a major gene or linked to the major gene to affect the weight traits and the polymorphic site could be used to select the goat weight in marker assisted selection program.