不同地方乌骨鸡种群遗传多样性的微卫星分析

【作者】 李亮；

【导师】 朱庆；

【作者基本信息】 四川农业大学 ， 动物遗传育种与繁殖， 2001， 硕士

【摘要】 本研究利用选自家禽基因组中的10个微卫星（Microsatellite）标记，对四川7个乌骨鸡种群及一个非乌骨鸡种群在这10个微卫星标记座位上的等位基因频率、微卫星的多态信息含量（PIC）、各群体的遗传杂合度（Heterozygosity）、群体间的遗传距离等进行了分析，并根据遗传距离对这几个乌骨鸡种群进行了UPGMA聚类分析。 结果表明，所选择的10个微卫星标记在所检测的群体中均表现出较好的多态性，每个微卫星标记平均检测到4.2个等位基因（2—6个），10个微卫星标记的平均多态信息含量（PIC）为0.5154（0.3587—0.5853）。乌骨鸡群体的各项指标与非乌骨鸡群体（海兰蛋鸡，HL）有较明显的差异，如乌骨鸡群体在10个微卫星位点的平均群体杂合度从0.5383（四川山地乌骨鸡白羽系，SB）到0.6659（黄忠山地乌骨鸡，SC），而海兰蛋鸡平均杂合度仅为0.3685，所计算的遗传距离和聚类分析结果也表明了乌骨鸡与非乌骨鸡群体间较大的遗传差异。各乌骨鸡群体内较高的遗传杂合度表明不同乌骨鸡群体的遗传多样性较为丰富，并具有较高的选择潜力。对遗传距离的计算结果表明各乌骨鸡种群间有一定的遗传距离，以四川山地乌骨鸡白羽系与草科乌骨鸡（CK）间的遗传距离较高（0.2118），而黑凤乌骨鸡与白凤乌骨鸡间的遗传距离较低（0.0298）。UPGMA聚类分析表明，黑凤乌骨鸡与白风乌骨鸡最先被聚在一起，四川山地乌骨鸡黑羽系与黄忠鸡场山地乌骨鸡被聚为一类，草科乌骨鸡与绿壳蛋乌骨鸡被聚为一类。这些聚类结果与根据形态学及育种历史等进行的预期结果基本一致，表明微卫星标记适宜于群体遗传结构及遗传关系的研究，是畜禽遗传多样性研究与保护的有效分析手段。更多还原

【Abstract】 Genetic diversity of eight chicken lines (seven of them are black-bone chicken collected in province Sichuan and the other is an egg chicken line) was evaluated on the basis of 10 microsatellite markers selected from the chicken Gene-Bank. Allele frequencies were estimated based on band presence or absence. Average breed (line) heterozygosity and genetic distance were calculated based on allele frequencies. And then, cluster analysis based on those calculated genetic distances lines was performed for the eight chicken lines. Every microsatellite loci analyzed were polymorphic in those chicken lines with an average number of alleles per locus and the average polymorphism information content (PlC) equal to 4.2 and 0.5 154 respectively. All calculated parameters were significantly different between black-bone chicken lines and the egg line (Hailan, HL). For example, The average heterozygosity often microsatellite loci in black-bone chicken lines was varied from 0.5383 (The white line of Sican Shandi black-bone chicken, SB) to 0.665 9 (Huangzhong Shandi black-bone chicken, SC) but that in Hailan egg chicken line was only 0.3685. The same conclusion could be taken from the result of genetic distance and UPGMA cluster analysis. The significantly higher heterozygosity suggested that black-bone chickens had abundant genetic diversity and potential of selection in Sichuan Province. The result of genetic distance indicated that there were some genetic difference among Sichuan black-bone chicken lines. The distance between the white line of Sichuan Shandi 41 black-bone chicken (SB) and the Caoke black-bone chicken line (CK) was the most significant and that between the white silky (BF) and the black silky (HF) was the lowest with the two values equaled to 0.2118 and 0.02 98 respectively. The UPGMA cluster analysis clustered the BF line and the HF line as one at first, then the black line of Sichuan Shandi black-bone chicken (SF1) and the SC line, the CK line and the line which laid green-shell eggs at a high proportion (LK). This result accorded with the expectation derived from the morphology and the breeding history of each line. This study, which still needs to be extended to research with more markers and more individuals, suggested that microsatellite DNA marker is a useful tool in detecting genetic diversity in closely related breeds and accessions.更多还原