虹鳟杂交胚胎(2n♀×3n♂)的发育状况及其DNA倍性分析  

Developmental observation of hybrid embryos(2n♀×3n♂) and analysis of DNA ploidy in Oncorhynchus mykiss

作　　者：王炳谦[1] 范兆廷[2] 户国[1] 杨翟平[2] 谷伟[1] 

机构地区：[1]中国水产科学研究院黑龙江水产研究所,黑龙江哈尔滨150070 [2]东北农业大学水产养殖系,黑龙江哈尔滨150030

出　　处：《中国水产科学》2011年第6期1321-1326,共6页Journal of Fishery Sciences of China

基　　金：公益性行业(农业)科研专项(201003055)资助;中央级公益性科研院所基本科研业务费专项(201110)资助;农业部淡水水产生物技术与遗传育种重点实验室专项(2011NYBSJ-02)资助

摘　　要：雄性三倍体虹鳟(Oncorhyncus mykiss)可以发育至生理成熟并表现出较强的雄性副性征,性腺发育基本正常;雌性三倍体虹鳟性腺几乎不发育,并且存在着类雄性化的发育趋势。本研究拟通过对虹鳟杂交胚胎(2n♀×3n♂)发育状况及其DNA倍性的分析,进而确认三倍体虹鳟是否具有与二倍体虹鳟类似的生育能力并分析其原因。选取经两个世代家系选育的虹鳟优良品系二倍体雌性虹鳟作为母本,以热休克方法人工诱导的优质雄性三倍体虹鳟为父本,常规人工采集精卵授精,获得三倍体雄性与二倍体雌性杂交胚胎,观察杂交胚胎的发育进程,通过流式细胞仪检测杂交胚胎的DNA含量,进而与二倍体雌雄交配获得的胚胎对照确定杂交胚胎的倍性。结果表明,杂交胚胎的受精率、发眼率和孵化率均显著地低于对照组,杂交胚胎多数在发眼期之前死亡,破膜的胚胎在仔鱼期上浮前全部死亡。杂交胚胎的DNA含量分布范围较大,大致可以分为两个水平,接近84%的胚胎的DNA含量介于二倍体与三倍体之间,约为对照组DNA含量的2.5倍;约有16%的胚胎的DNA含量在三倍体和四倍体之间。本研究认为,染色体非整倍体化可能会引起杂交胚胎细胞核质不相容,进而导致基因表达调控紊乱,从而使杂交胚胎不能正常发育,无法完成由母体卵黄供给的内源营养向外源营养的转换,成为导致杂交胚胎发育过程中大量死亡,以及杂交仔鱼在破膜之后开始进食之前全部死亡的一个重要原因。Male triploid rainbow trout （Oncorhynchus mykiss） can develop to physiology maturity and exhibit strong secondary sex characters. Conversely, the gonads of female triploid rainbow trout are typically underdeveloped and are characterized by a masculization-like phenomenon. We evaluated the effect of chromatosome polyploidy on the reproductive potential of triploid male rainbow trout. We obtained hybrid embryos by artificially inseminating diploid female trout with sperm from triploid male rainbow trout. The diploid females were obtained from a superior strain of two generation family selective breeding. The male triploid was obtained by artificially inducing triploidy using heat shock. We monitored the development of the hybrid embryos and measured their DNA content （ploidy） using flow cytometry. The fertility, eyed rate, and hatching rate of hybrid embryos were significantly lower than the control diploid embryos （P〈0.05）. The embryos and fry died during early development or within a short time after hatching. There was considerable variation in the DNA content of the hybrid embryos. The ploidy of most （84%） hybrid embryos ranged from 2n to 3n and their DNA content was ~2.5 times that of the control embryos. The ploidy of the remaining 16% ranged from 3n to 4n. Our results suggest that aneuploidy of hybrid embryos may result in incompatibility of the karyoplasm between the gametes of male triploid and female diploid rainbow trout. We hypothesize that the hybrid embryos do not survive because of disorders of gene expression and regulation.

关 键 词：虹鳟 非整倍体 杂交胚胎 发育 DNA倍性 

分 类 号：S961[农业科学—水产养殖]