转生长激素基因三倍体鲤鱼的快速生长与不育特性

将转草鱼生长激素基因黄河鲤(♂)与改良四倍体鲫鲤(♀)交配, 获得100%三倍体子代“鲤鱼”. 通过特异引物PCR检测, 子代鲤鱼包括转基因(简称阳性鱼)和非转基因(简称阴性鱼)两部分, 其中阳性鱼占总检测鱼数的44.2%; 染色体检测表明, 子代转基因鲤鱼的染色体数目为3n=150; 组织切片结果表明性腺不能发育成熟; 在同龄的鲤鱼繁殖季节(24月龄), 转基因三倍体鲤鱼仍不能产生成熟配子. 阳性和阴性三倍体鲤鱼在形态上无明显差异, 它们的体侧扁, 近似纺锤形, 体色青灰, 有两对口须, 大部分可测量性状和可数性状都介于父母本之间, 表现出杂种特征. 2年同塘养殖结果表明, 阳性鱼的平均体重为阴性鱼的2.3倍; 其中最大阳性鱼个体的体重为最大阴性鱼的2.91倍. 因此, 本研究不仅证实了转基因三倍体鲤鱼的生长快速特性, 而且第一次用实验消除了转基因鲤鱼养殖应用上的生态安全之虑.

The fast growth and sterility of the growth hormone gene transgenic triploid carps

Triploid carps (100%) with 150 (3n=150) chromosomes were obtained by crossing improved tetraploid hybrids (♀, 4n=200) of red crucian carp common carp with diploid yellow river carp (♂, 2n=100). Using PCR detection with specific primers, the transgenic triploid carps (positive triploid fish) which accounted for 44.2% and the non-transgenic triploid carps (negative triploid fish) were identified from the triploid carps. On tissue sections, the gonads of 24-month-old positive triploid fish were found to be sterile, and were not able to produce mature gametes during the breeding season. Morphologically, both the positive and negative triploid fish were similar. They had a spindle-shaped, laterally compressed, steel grey body with two pairs of barbels. Most of the countable and measurable traits of the triploid carps were intermediate between those of the two parents. Over the last 2 years, the positive and negative triploid fish have been raised in the same ponds. The mean body weight of the positive triploid fish was 2.3 times higher than that of the negative triploid fish. The highest body weight of the positive triploid fish was 2.91 times higher than that of the negative triploid fish. Thus, this study produced fast-growing transgenic triploid carps with reduced ecological risk because of their inability to mate and produce progeny.