【作者】 杨晓燕；

【导师】 吴常信；

【作者基本信息】 中国农业大学 ， 动物遗传育种与繁殖， 2004， 硕士

【摘要】 鸡的肤色、胫色和脚色等重要色素性状的遗传不仅是品种或种群的特征，而且也和鸡的经济用途有重要关系。本实验选用羽色一致、胫色相近、只在肤色与内脏颜色有较大差异的中国地方鸡种东乡黑羽绿壳蛋鸡与山东寿光鸡作为亲本构建了一个F2代资源群体，旨在研究鸡的主要颜色性状—肤色的遗传规律。本研究详细记录了资源群体的肤色、胫色、脚色及屠体颜色等色素性状表型。有研究表明黑色胫为伴性遗传，受到位于性染色体上的隐性基因id控制，而肤色则受常染色体上的P基因影响。在本群体中，胫色没有出现明显的分离，而肤色出现了明显黑白肤色的性状分离，这表明控制胫色的隐性性连锁基因id在资源群体中没有分离，而位于常染色体上的控制肤色的主效基因P基因处于分离状态，在此基础上，本研究进一步探明了P基因资源群体中的遗传模式，为进一步定位P基因奠定了基础；同时本研究群体中的肤色分离表明，寿光鸡的常染色体上P座位处于显性纯合状态，即该座位的基因型为PP，而东乡绿壳蛋鸡在该座位上的基因型不纯合，即该座位上有两种基因型分别为PP和Pp，这将为绿壳蛋鸡的进一步选育提供理论依据。 鸡的黑色素抑制基因（Dermal melanin inhibitor，ID）被认为是与黑色素的调控有重要关联的基因，定位于Z染色体长臂末端约186-214cM内，然而对ID基因的研究进展缓慢，主要原因是Z染色体长臂末端是一个标记贫瘠区。本实验利用位于ID基因上游的三个已知序列基因设计引物，以本实验室构建的丝羽乌骨鸡的BAC文库为基础，采用染色体步行的方法钓取ID基因附近的BAC克隆，以这些BAC克隆为基础构建富集微卫星文库和常规小片段插入文库对Z染色体长臂末端标记的研究方法进行探讨。实验共筛选出46个BAC克隆，对富集微卫星文库中的插入片段测序，得到三个阳性片段，经序列比对发现为同一个微卫星标记（AC）₁₀；对常规小片段插入文库采用³²P标记探针、膜原位杂交筛选，没有发现含有微卫星的克隆片段。 研究结果表明常规小片段插入文库与富集微卫星文库的方法都不适合于Z染色体这样的本身标记含量就非常稀少的染色体特定区段。结合本实验的结论，作者认为要对ID基因做进一步的研究，应该对Z染色体末端全部测序，大量发展SNP标记，对ID基因进行精细定位，寻找与ID紧密连锁的SNP，最后用图位克隆的策略定位ID基因。更多还原

【Abstract】 Melanin trait is not the important feature of some breed, but is related with economic purpose. A three-generation chicken population was constructed for mapping gene controlling the genetics of skin color. The Dongxiang blue egg shell chicken with black skin and Shouguang chicken with white skin were employed for reciprocal cross. Test traits included skin color, leg color, feet color and pigments in parts of slaughter trait. The analysis based statistics of phenotye showed the recessive sex- linked gene id , which affects the skin color, is in pure. While another autosomal gene P, which is a major gene controlling skin melanin, are showed segregate. Furthermore, we delineate the genetic pattern of P gene in our population. This will be propitious to map P gene. At the same time, our research exhibited the genotype in Shouguang chicken is PP, when in Dongxiang chicken the gene is heterozygous, which will establish the foundation for the further breeding in Dongxiang chicken.ID (Dermal melanin inhibitor) is considered a key gene attached to the regulation of melanin synthesize, and was mapped to the bottom on Z chromosome. One important reason why the advance of mapping of ID gene is slow is the density of maker on the region is too low. In the research, three genes, ACO1, GGTB2, XPA, are employed to design primers. With these primers we isolated 46 BAC clones near ID gene from the chicken BAC library by chromosome walking. Based these BAC clones we constructed enriched and no-enriched satellite library. By sequencing of enrich satellite library we got one fragment of 197 bp containing (AC))0 .Via hybridation we found no satellite.Our research indicates that the two methods, enrich and no-enrich, are not the best to research the makers located the bottom of Z chromosome. Markers in this region are rarely on theory. Integated our rearch, the author give some advice on mapping ID. We should sequence the whole bottom of Z chromosome to find large of SNP, from which we can get the SNP linked closely to ID by linkage anylasis. Then ID gene can be sequenced by map-based clone.更多还原