中国乌骨鸡遗传多样性及家鸡起源研究

【作者】 刘益平；

【导师】 曾凡同； 邱祥聘； 张亚平；

【作者基本信息】 四川农业大学 ， 动物遗传育种与繁殖， 2002， 博士

【摘要】 本文共测定了19个乌骨鸡品种(品系)及8个非乌骨鸡品种(品系)的243个家鸡和38个原鸡个体(属于Gallus.gallus.spadiceus和Gallus.gallus.jabouillee亚种)的线粒体D-环高变区(mtDNA HVS-Ⅰ)539bp的部分序列，另外还测定了5个红原鸡个体线粒体细胞色素b的289 bp序列、19个珍珠鸡个体、18个骡鸡个体的线粒体D环高变区序列、30个家鸡个体线粒体D环非高变区的690bp序列以及34个家鸡及原鸡个体的MC1R基因编码区的945bp。对这些序列片段及其它已经发表的相应序列片段进行了邻接法、网络图法等分析，得出如下主要结论： 1、8个丝羽乌骨鸡群体的66个个体的线粒体D环539bp中共有23个变异位点，14种单倍型，分析表明丝羽乌骨鸡来源于多个母系，是在不同的地方长期人工选育的结果。 2、124个常羽乌骨鸡的线粒体D环高变区序列中共有39个变异位点，可分为34种单倍型，从中可以看出常羽乌骨鸡的母系来源类型很多，至少有六个不同的原鸡母系来源。 3、丝羽乌骨鸡为常羽乌骨鸡的突变型，常羽乌骨鸡有比丝羽乌骨鸡更多的单倍型类型，而且在丝羽乌骨鸡群体中出现的几种主体单倍型类型也是常羽乌骨鸡群体的主体单倍型。 4、在中国的两个红原鸡亚种的线粒体D环高变区序列与在泰国等地分布的红原鸡亚种的此段序列差异不大，可归为一类，而与爪哇岛上分布的红原鸡亚种的此段序列差异较大。我们的结果支持红原鸡可以分为陆地型亚种和海岛型亚种。 5、314个家鸡个体和62个原鸡个体的线粒体高变区序列共有66个变异位点，79种单倍型，可划分为9大类群。家鸡和原鸡共同拥有的单倍型有7个，由此可推论所有家鸡都有共同的祖先，可能都来源于陆地型红原鸡，并经受了多次独立驯化。 6、在本实验中，线粒体D环非高变区序列对家鸡起源分析的结果同于高变区序列分析，所以，选择高变区来研究物种的遗传多样性和起源进化是经济、有效的。 7、在家鸡和原鸡黑色素受体1(MC1R)基因编码区的945个碱基中，34个个体共有10个变异位点，其中第28位、69位、159位、637位为同义突变；翻译成氨基酸后，有变异的6个氨基酸的位置分别是10、71、92、213、215、307，其中71、213、215、307有氨基酸杂合的情况。在这些突变的氨基酸位点中，突变与羽毛颜色间除了丝羽乌鸡外均有一一对应关系，这可能提示乌鸡的丝羽口 及颜色受多个基因的调控，MC IR基因可能是其中的一个主效但不是唯一的质 量性状基因。 8、黑羽常羽乌骨鸡和珍珠鸡的线粒体D环高变区序列存在长度变异，乌骨鸡的此 段序列长度为539hp，珍珠鸡的序列是498hp，而骡鸡个体的此段序列或同于乌 骨鸡、或同于珍珠鸡。因此，本结果支持骡鸡是乌骨鸡和珍珠鸡的杂交后代。更多还原

【Abstract】 In the present paper, we determined the mitochondrial DNA sequence 539bp of the high variable I D-loop regions(mtDNA HVS-I) for 243 domestic fowls (19 were Wugu (or black-bone chicken) and 8 non-wugu breeds/races) and 38 red jungle fowls (Gallus. Gallus. spadiceus and Gallus. Gallus. jabouillei). We also sequenced 289bp mitochondrial DNA of Cyt-b for 5 red jungle fowls; D-loop region (mtDNA HVS-I)for 19 individuals Guinea fowl and 18 individuals mule chickens (Guinea fowl $ x Wugu chickens^ ) respectively; mtDNA HVS- II of D-loop region for 34 individuals of domestic fowls and red jungle fowls in 690bp and the MC1R code gene in 945 bp. Analyzing this data together with the same sequence part available in genbank by neighbor joining and network etc, we can draw some conclusion as follow:1. There were 23 mutation sites in mtDNA HVS-I of 66 individuals among 8 populations; it could be divided into 14 haplotypes. The result suggested that Silkies had several maternal ancestors. It was the result of long artificial selection in different place.2. There were 39 mutation sites in mtDNA HVS-I of 124 individuals; it could be divided into 34 haplotypes. The normal feather Wugu chickens also had a lot of maternal ancestors; the result showed that at least six populations of red jungle fowl contributed to the gene pool of the domestic fowls.3. Silkies were the mutation type of nomal feather Wugu chicken for it had more haplotypes and shared the major haplotypes with silkies.4. The sub-species of G. g. spadcieus and G. g. jabouillee in China were at the same clade with the G. g. gallus in and around the Thailand area, but were in difference clade with G. g. bankiva in Java island, so our result support the opinion that red jungle fowl could be classified as mainland type and island type.5. There were 66 mutation sites in mtDNA HVS-I of 314 domestic fowls and 62 red jungle fowls, it could be divided into 79 haplotypes, these haplotypes belong to nine clades. So, All the domestic fowl shared the same maternal ancestor of red jungle fowl and were domesticated several times independently in different places.6. In our studying, the mtDNA HVS-I and the mtDAN HVS- II showed the same result, so, it was suitable , high efficiency and economical to choose mtDNA HVS-I as a marker studying for the genetic divergence and evolution of species.7. There were 10 mute sites in the MC1R gene in 945 bp code region of the domestic fowls and red jungle fowls in all 34 individuals, in these mute sites, the 28th, 69th, 159th, 637th point mute sites were synonymous mutes, while the 10th 71th,92th, 2135h, 215th, 307th sites were amino acid mutation sites, among them , 71th, 213th, 215th, 307th were hybrid sites. We couldn’t see the line-relationship of the mute sites and the feather color types; maybe MC1R was just one major but not only silky feather color functional gene, the feather color maybe controlled by several genes.8. There were length differences when using the same primer to amplify the mtDNA HVS-1 of black normal feather Wugu chickens and Guinea fowl. The PCR production sequence length of them were 539bp and 498bp respectively, the same region sequence of mule chicken were the same as Guinea fowl or black normal feather Wugu chickens. So, it suggested that the mule chickens were the progeny of Guinea fowl and the black normal feather Wugu chicken.更多还原