【摘要】 肤色遗传研究表明,乌骨鸡的乌度性状主要由纤维黑色素基因(FM)和真皮黑色素抑制基因(ID)共同作用决定。FM基因内的两个基因片段(Dup1和Dup2)的异常复制可能是引起乌骨鸡黑色素过度沉淀的关键因素。试验利用白羽肉鸡与丝羽乌鸡杂交经三代闭锁选育后的群体,7周龄时选取体重相近肤色差异较明显的黑色皮肤公鸡(BS)200只和灰色皮肤公鸡(GS)200只,于7、10、15周龄测定皮肤不同位点的L、a和b值,结合系谱信息估计色度指标的育种值,并挑选肤色差异最极端的个体各50只,利用荧光定量PCR检测Dup1和Dup2基因片段的拷贝数,分析拷贝数与肤色之间的关系。结果显示:L、a和b值育种值分别介于0.31~0.35,0.32~0.38和0.16~0.21之间;肤色差异随周龄增加逐渐减小,该性状的选择宜早不宜晚;肩部和肛门周围裸露皮肤的L值在两组间差异显著,可作为选育的主选指标并综合考虑a和b值;两组个体之间的Dup1和Dup2基因拷贝数没有明显差异,无法用于分子标记辅助选择。更多还原

【Abstract】 Genetic studies of skin color indicated that the umbilicus traits of Silkie chicken were mainly determined by the combination of the autosomal dominant fibromelanosis(FM) and the sex-linked incompletely dominant inhibitor of dermal melanin(ID). Aberrant replication of two gene segments(Dup1 and Dup2) within the FM gene may be a key factor in causing excessive melanin deposition in Silkie chicken. In this experiment, hybrids of White feather broiler and Silkie chicken, which through three generations of atresia breeding were used as the experiment chicken. At the age of 7 weeks, 200 black skin chickens(BS) and gray skin chickens(GS) with obvious differences in skin color were selected. The L, a, and b values at different sites of the skin were measured at 7, 10, and 15 weeks of age, and the breeding values of the color index were estimated based on pedigree information. Fifty individuals with the most extreme differences in skin color were selected, and Dup1 and Dup2 was detected by real-time PCR. The copy number of Dup1 and Dup2 gene fragment was analyzed for the relationship between copy number and skin color. The results showed that the breeding value of L, a and b values were between 0.31 to 0.35, 0.32 to 0.38 and 0.16 to 0.21. The difference of skin color gradually decreased with the increase of age. The selection of this character should be earlier than before. The skin around the shoulder and anus was exposed. The L values were significantly different between two groups, which can be used as the main selection indicator of breeding and comprehensively consider the a and b values.There was no significant difference in the copy number of Dup1 and Dup2 between the two groups and could not be used for molecular marker-assisted selection.更多还原