中国乌骨鸡品种BCDO2基因多态性和肤色鉴定

为分析β-胡萝卜素脱氧酶2(β-carotene dioxygenase2, BCDO2)基因在我国乌骨鸡中的变异情况，采用PCR方法分别扩增和测序了我国5个乌骨鸡品种(丝羽乌骨鸡、东乡绿壳蛋鸡、金湖乌凤鸡、余干乌骨鸡和新兴竹丝鸡3号)、白耳黄鸡(黄肤色)和崇仁麻鸡(白肤色)的BCDO2基因，并与GenBank数据库中的原鸡序列进行系统发育分析。结果显示：7个品种215条序列，总计发现6个多态位点，分别为6273091(G-A)、6273129(A-G)、6273229(C-T)、6273240(C-T)、6273307(A-G)和6273672(A-G)。基于6个多态点界定了3种单倍型，定义为Hap1、Hap2和Hap3。其中只有白耳黄鸡、崇仁麻鸡和丝羽乌骨鸡有1种单倍型，东乡绿壳蛋鸡、金湖乌凤鸡、余干乌骨鸡和新兴竹丝鸡3号均有2种单倍型。系统发育分析显示：Hap1和Hap2只与红色原鸡聚为一类，Hap3和多个原鸡聚为一类。BCDO2基因多态位点能够很好地区分黄白肤色的品种，但很难区分乌骨鸡品种。多个原鸡在我国乌骨鸡品种形成过程中都做出了贡献。该研究结果为我国乌骨鸡遗传资源的保护、选育和鉴定工作提供了遗传背景信息。

BCDO2 gene polymorphism and skin color identification in Chinese black-bone chicken

To test the BCDO2 gene polymorphism in Chinese black-bone chicken, five black-bone chicken breeds (Silkie, Dongxiang Blue-eggshell, Jinhu Black-bone, Yugan Black-bone and Zhusi), Chongren Partridge chicken with white skin and Baier Yellow chicken with yellow skin were collected, and the sequence of the BCDO2 gene was PCR amplified, subsequently sequenced and analyzed with the DNA data of jungle fowl annotated in the GenBank. Six polymorphic sites were found in 215 sequences of seven breeds, which were 6273091(G-A), 6273129(A-G), 6273229(C-T), 6273240(C-T), 6273307(A-G) and 6273672(A-G). The 3 haplotypes were observed based on 6 polymorphic sites, which were Hap1, Hap2 and Hap3. Chongren Partridge, Baier Yellow and Silkie only had one haplotype, while Dongxiang Blue-eggshell, Jinhu Black-bone, Yugan Black-bone and Zhusi all had two haplotypes. The phylogenetic analysis showed that Hap1 and Hap2 were only clustered with Red jungle fowl, and Hap3 was clustered with multiple jungle fowl. Our data suggested polymorphisms in the BCDO2 gene can be regarded as markers for yellow and white skin color of chicken, but it cannot be used in black-bone chicken. There are multiple maternal contributed to the evolution of Chinese black-bone chicken. Our results can be used as a reference for preservation, improvement and identification of Chinese black bone chickens.