基于标记系谱的红鳍东方鲀生长性状遗传分析

利用分子标记辅助家系选育进行红鳍东方鲀生长性状的遗传评估,由红鳍东方鲀基础群体中选择性腺发育良好的雌雄亲本各11尾建立全同胞家系11个,每个全同胞家系随机采集10尾个体组建全同胞家系群体,从混合培育的家系中选择相对较大的个体400尾组建混合选育群体。在红鳍东方鲀遗传连锁图谱上挑选44个均匀分布于22个连锁群上的微卫星DNA标记,每个连锁群有2个标记。全同胞家系群体的遗传分析结果显示,10个高亲本排除概率微卫星标记的Excl(1)和Excl(2)为0.58~0.662和0.736~0.797,14个低亲本排除概率标记的Excl(1)和Excl(2)为0.054~0.43和0.177~0.608,剩余20个中等亲本排除概率标记的Excl(1)和Excl(2)为0.467~0.575和0.641~0.732。利用拥有高亲本排除概率的微卫星DNA标记进行混合选育群体的亲权鉴定,结果显示:不同父母本繁殖产生的子代数量存在明显差异,父本M2和母本F4产生了124个子代,占子代个体总数的32.89%。根据亲权鉴定结果建立的系谱估计主要生长性状的遗传参数,不同日龄的体质量和体长遗传力估计值为0.17~0.21和0.15~0.18。研究表明,利用具有高亲本排除概率的微卫星DNA标记能够有效建立红鳍东方鲀系谱,进行生长性状的遗传参数估计,分子标记辅助家系选育可以作为红鳍东方鲀目标性状遗传改良的新方法。

Genetic analysis of redfin puffer (Takifugu rubripes) for growth traits by using a marker-based pedigree

To carry out genetic evaluation on growth traits in redfin puffer by using molecular marker assist family selection and breeding, in this study, the mature 11 females and 11 males chosen from the selection and breeding founder were used to produce 11 full-sib families of redfin puffer. 10 individuals from each family separately raised were random selected to construct the family population. About 400 larger individuals from the families raised together were random selected to construct the mixed breeding population. A set of 44 microsatellite DNA markers distributed evenly on 22 linkage groups were selected from the genetic linkage maps of redfin puffer, furthermore, 2 markers were located on each linkage group. According to the Excl 1 and Excl 2 probabilities based on the results of genetic analysis in full-sib family population, high probability values of 10 markers ranged from 0.58 to 0.662 and 0.736 to 0.797, low probability values of 14 markers were from 0.054 to 0.43and 0.177 to 0.608, and intermediate probability values of the remainder 20 markers showed 0.467 to 0.575 and 0.641 to 0.732. The results of parentage determination of mixed breeding population by using these markers with higher parental probabilities demonstrated that there were differences in the number of offspring from the combination of different parent. Male M2 and female F4 generated 124 offspring, whose percentage of all the individuals attained to 32.89%. Estimating the genetic parameters of growth traits with the marker-based pedigree according to the results of parentage determination, the heritabilities of body weight and body length were from 0.467 to 0.575 and 0.641 to 0.732 at different days of age, respectively. The research results verified that the microsatellite DNA markers selected with higher parental probabilities of exclusion can effectively construct the pedigree in redfin puffer to perform the estimation of genetic parameters for growth traits, therefore, molecular marker-assisted family selection is an efficient approach to genetically improve objective traits in this species.