牙鲆家系亲权鉴定的微卫星DNA标记分析

Parentage determination in Japanese flounder( Paralichthys olivaceus)families by microsatellite DNA marker analysis

为准确进行不同家系的亲权鉴定,筛选具有高亲本排除概率的微卫星DNA标记,从牙鲆选育基础群体中挑选性腺发育良好的雌雄亲本各10尾建立全同胞家系10个,从独立饲养的每个家系中随机选取30尾个体组成系谱结构已知的家系群体,从混合培育的子代群体中随机选取200尾个体组成系谱结构未知的混合群体。48个微卫星DNA标记选自牙鲆第二代遗传连锁图谱,且均匀分布于24个连锁群上,每个连锁群2个标记。家系群体的遗传分析结果发现,10个拥有丰富遗传多态性的微卫星DNA标记表现出高的亲本排除概率,其Excl 1和Excl 2的范围分别为0.655-0.719和0.792-0.837。随鉴定所用微卫星DNA标记数目的增加,累计排除概率逐步升高。当使用8个微卫星DNA标记鉴定时,累计排除概率达到100%。利用这些标记开展混合群体的亲权鉴定,显示共有13个雌雄个体参与繁殖过程,不同亲本配组产生的后代数量存在差异,亲本与后代群体之间的各项遗传学统计指标不存在明显差异。研究表明,筛选出具有高亲本排除概率的微卫星DNA标记能够有效进行牙鲆家系的亲权鉴定,可以作为今后开展家系选育与DNA分子标记联合育种的候选标记。

To carry out accurately the parentage determination on different families in Japanese flounder and select the microsatellite DNA markers with higher parental probabilities of exclusion,in this study,10 mature females and 10 mature males chosen from the selection and breeding founder were used to produce 10 fullsib families of Japanese flounder. 30 individuals from each family separately raised were random selected to construct the family population whose pedigree structure was known. 200 individuals from the families raised together were random selected to construct the mixed population whose pedigree structure was unknown. A set of 48 microsatellite DNA markers distributed evenly on 24 linkage groups were selected from the second genetic linkage maps of Japanese flounder,furthermore,2 markers were located on each linkage group. The results showed that 10 microsatellite DNA markers took on the higher parental probabilities of exclusion and richer genetic polymorphism based on the genetic analysis of family population,and their range for Excl 1and Excl 2 was from 0. 655 to 0. 719 and from 0. 792 to 0. 837,respectively. The combined probabilities of exclusion gradually increased as the number of markers identified increased. It reached 100% when 8microsatellite DNA markers were jointly used. The results of parentage determination of mixed population by using these markers demonstrated that 13 females and males contributed to the reproduction in total. To some extent,there were differences in the number of offspring from the combination of different parents.Moreover,significant differences did not exist in each genetic statistical data between the parental and progeny populations. The research demonstrated that these microsatellite DNA markers selected with higher parental probabilities of exclusion can effectively perform the parentage determination on family in Japanese flounder,therefore,they are designated as candidate markers to develop joint breeding by combining the family selection with DNA molecular marker in future.