利用紫外线诱导进行栉江珧(Atrina pectinata)雌核发育单倍体的研究,用强度为2561μW/(cm^2·s)的紫外线(254nm)照射不同时间的精子与正常卵子受精展开实验。结果发现随照射时间的增加,卵裂率、甲期胚胎存活率和D型幼虫发生率总体呈下降趋势,遗传失活的精子与正常卵子受精后其胚胎发育至D型幼虫前期停止。经紫外线照射的精子受精后所产生的单倍体胚胎发育速度慢于正常受精所产生的二倍体胚胎,各照射组均出现非整倍体。40s照射组中卵裂率达到51.2%,D型幼虫发牛率为0,单倍体率最高,达到36.8%,出现“Hertwig效应”。由于雌核发育单倍体的有效诱导既需要精子遗传物质失活、又需要保证较高的卵裂率,因而在强度2561μW/(cm^2·s)的紫外线下照射40s是获得栉江珧雌核发育单倍体的最佳条件。
The effects of ultraviolet (UV) irradiation on genetic inactivation of sperm were examined in the Atrina pectinata. The sperms irradiated by UV at an intensity of 2 561 W/(cm^2·s) for various durations were fertilized with the normal eggs. With increasing irradiation time, the rates of cleavage, survival at the early embryo stage, and development of D-larvae decreased, and the development of the eggs fertilized with the genetically inactivated sperm terminated before reaching the D-larvae stage. The development speed of gynogenetic embryos was later than that of the control group, and aneuploids were found in this study. The obvious improved survival of trochophore larvae with a peak at 40 s UV exposure suggested the presence of a Hertwig effect in the gynogenesis of A. pectinata. When sperms were irradiated for 40 s, the cleavage rate was relatively high (51.2%), the developmental rate of D-larvae became zero, and the rate of haploid reached the highest (36.8%). As effective induction of haploid gynogenesis required the inactivation of sperm DNA and high cleavage rate, UV irradiation at an intensity of 2 561 W/(cm^2·s) for 40 s was considered to be the optimum dose to achieve haploid gynogenesis in the A. pectinata.