摘要：
旨在探究贵妃鸡多趾性状的遗传规律和多趾候选基因在胚胎发育时期的表达,为贵妃鸡多趾品系的选育和多趾分子标记的开发奠定基础.选用不同趾型(四四趾、四五趾、五五趾)的贵妃鸡进行杂交和测交试验,统计分析后代各种趾型出现的比例,与理论值进行卡方检验.采取胚胎发育第5～10天的肢芽组织样品,测定分析多趾候选基因Lmbr1、SHH、RNF32、NOM1、MNX1、Gli3的表达量.结果表明,四五趾×四五趾组合多趾与正常趾的比例为3.67:1,符合3∶1的理论比值(P＞0.05),另外两个组合都不符合理论比值(P＜0.05).其次,测交试验表明,每只测交公鸡后代都出现3种趾型的个体;最后,在贵妃鸡肢芽组织胚胎发育的第5～10天中,SHH基因的表达量一直很低,Lmbr1、RNF32、NOM1、MNX1、Gli3基因在第7和第9天出现表达峰值.贵妃鸡多趾性状为常染色体显性遗传,但多趾性状外显率不同,多趾性状可能受到Lmbr1、RNF32等多基因的共同调控,多趾性状形成的关键时期可能是胚胎发育的第7～9天.%The purpose of this study was to explore the genetic rules of polydactyly traits and the expression of its candidate genes during embryogenesis in order to provide a basis for the selection and breeding of polydactyly traits lines in Royal chicken.Royal chicken with different toe types (four-four toe,four-five toe,five-five toe) were selected,and hybridization and crossbreeding test were carried out to analyze the proportions of various toe types in offsprings,then it was compared with the theoretical values by Chi square test.The limb bud tissue samples from 5th to 10th day during embryonic development were collected and the expression of the polydactyly traits candidate genes(Lmbr1,SHH,RNF32,NOM1,MNX1 and Gli3) were analyzed.The results showed that the ratio of polydactyly to normal dactyly in four-five toe ♂ × four-five toe ♀-group was 3.67 ∶ 1,which was in accordance with the theoretical ratio of 3 ∶ 1 (P＞0.05).The other two groups did not fit the theoretical ratio (P＜0.05).Secondly,the result of crossbreeding test showed that there were 3 toe types in offsprings from each cross male.Finally,the expression of SHH gene was very low from the 5th to 10th day during the development of limb bud tissue in Royal chicken.Lmbrl,RNF32,NOM1,MNX1,Gli3 gene expression peaks appeared on the 7th and 9th day during the development of limb bud tissue.The polydactyly trait of Royal chicken is in form of autosomal dominant inheritance,but its penetrance is different.The results indicate that the polydactyly traits may be regulated by multiple genes such as Lmbr1 and RNF32,and the critical period may be from the 7th to 9th day during embryo development.
