牙鲆连续三代减数分裂雌核发育家系的遗传特征分析

通过对连续两代减数分裂雌核发育牙鲆(Paralichthys olivaceus)再度诱导减数分裂雌核发育,首次获得三个连续三代减数分裂雌核发育二倍体家系(Meio-G3-1,Meio-G3-2,Meio-G3-3)。选用重组率高、中、低的30对微卫星引物,分析该三个家系的遗传构成。30个微卫星位点在三个家系中扩增到的等位基因数分别为35、38、37,平均等位基因数为1.17、1.27、1.23,平均观测杂合度(Ho)分别为0.1467、0.2556、0.2056,平均纯合度分别为0.853 3、0.744 4、0.794 4。三个家系内个体间的平均遗传相似度为0.991 3、0.991 8、0.983 8,母本与子代之间的平均遗传相似度为0.994 6、0.996 8、0.992 3,三个家系间的遗传相似度分别为0.971 7(Meio-G3-1和Meio-G3-2)、0.981 0(Meio-G3-1和Meio-G3-3)、0.971 4(Meio-G3-2和Meio-G3-3)。结果表明,连续三代诱导雌核发育能进一步提高个体的纯合度、个体间以及家系间的平均遗传相似度,是快速建立鱼类近交系的良好方法。

Analysis of genetic structure of three third-generation of successive meiogynogenetic families in Japanese flounder, Paralichthys olivaceus

Three third-generation of successive meiogynogenetic families (Meio-G3-1, Meio-G3-2 and Meio-G3-3) in Japanese flounder (Paralichthys olivaceus) were induced by artificially meiogynogenesis, which the eggs were activated by UV-irradiated red sea bream (Pagrus major) sperm, and followed with the cold-shock treatment. We evaluated the genetic structure of these three families using 30 microsatellite markers, and the efficiency of successive meiogynogenesis for producing highly inbred line was quantified by calculating the homozygosity and genetic similarity. The numbers of alleles detected were 35, 38 and 37 in Meio-G3-1, Meio-G3-2 and Meio-G3-3, respectively. And for these three families studied, the average numbers of alleles (A) were 1.17, 1.27 and 1.23; the average observed heterozygosity (Ho) were 0.1467, 0.2556 and 0.2056; the average homozygoisty among the 30 analyzed loci were 0.8533, 0.7444, and 0.7944. For the genetic similarity, the average similarity index between offspring within family was 0.9913, 0.9918 and 0.9838; between dam and offspring was 0.996, 0.9968 and 0.9923; and between families was 0.9717 (Meio-G3-1 and Meio-G3-2), 0.9810 (Meio-G3-1 and Meio-G3-3) and 0.9714 (Meio-G3-2 and Meio-G3-3), respectively. Our results indicate that the artificially induced successive meiogynogenesis can increase the homozygosity of individual, and also the genetic similarity of offspring within family and between families. And therefore, the artificially induced successive meiogynogenesis is a good method to establish inbred lines in fish.