性别特异分子标记在斑鳢全雄育种上的应用

Application of sex-specific molecular markers for all-male breeding in Channa maculata

为了快速筛选培育出全雄斑鳢,本研究结合性别特异分子标记和三系配套育种技术,开发了全雄斑鳢的育种方法。将健康的七日龄斑鳢幼鱼随机分成3组进行雌化处理,在饲料中分别添加雌二醇(E2)100、300、600 mg/kg,饲养60 d。利用性别特异分子标记引物M12、P2鉴定筛选出决定型为XY型斑鳢,将XY型正常雄鱼与XY型伪雌鱼交配,获得的子代分为两组,一组为投喂正常饲料,另一组进行雌激素投喂,利用MX1和MX3引物筛选出YY超雄鱼,最后将YY超雄鱼和正常雌鱼作为亲本交配生产出全雄斑鳢子代。结果显示,600 mg/kg激素浓度组的性逆转率最高,达75%,从508尾经雌激素E2投喂的家系中筛选获得235尾具有XY基因型斑鳢。XY伪雌鱼与正常雄鱼交配获得的子代在2月龄时检测到22尾YY超雄鱼,7月龄时检测到14尾YY超雄鱼,筛选获得YY超雄鱼个体用于生产全雄子代。本研究方法显著提高了全雄化斑鳢育种效率,缩短了育种周期,展现出巨大的经济潜力和应用价值,为其他鱼类开展性别特别分子标记辅助育种提供借鉴或参考。

In order to rapidly select and breed all-male Channa maculata,this study developed a breeding method for all-male Channa maculata by combining sex-specific molecular markers and the three-lines breeding technology.Healthy seven-day-old Channa maculata juveniles were selected for feminization,and the juveniles were randomly divided into three groups,and 100,300 and 600 mg/kg of estradiol hormone was added to the feed for 60 d.The sex-specific molecular markers M12 and P2 were used to identify and screen out Channa maculata with the determinant of XY type.Next,the offspring obtained by mating XY-type normal males with XY-type pseudo-females were divided into two groups,one was fed with normal feed,and the other was subjected to estradiol hormone treatment.YY super males were screened using MX1 and MX3 primers,and finally,YY super males and normal females were mated as parents to produce all-male Channa maculata offspring.The results showed that the 600 mg/kg hormone concentration group had the highest sex reversal rate of 75%,and 235 Channa maculata with the XY genotype were screened from 508 lines fed with estrogen E2.22 YY hypermales were detected at 2 months of age in the offspring obtained by mating XY pseudo-females with normal males and 14 YY hypermales were detected at 7 months of age.All the screened Channa maculata individuals were used to produce all-male offspring.The present method significantly improved the breeding efficiency and shortened the breeding cycle of Channa maculata,and showed a great economic potential and application value,which can be used as a reference for gender-specific molecular marker-assisted breeding in other fish species.