鱼类染色体组操作的研究 Ⅰ.静水压休克诱导三倍体水晶彩鲫

采用静水压休克方法研究了促使第二极体保留诱发三倍体水晶彩鲫的最佳条件。在卵受精后4—5min采用600kg/cm~2或650kg/cm~2的静水压处理3min,不但能导致100％的三倍化,而且胚胎的存活率相当高,孵化率为对照组的90％左右。研究表明,静水压休克是进行鱼类染色体组操作的有效方法,休克的最佳条件易于掌握,处理程序易于标准化。文中讨论了静水压处理的条件与三倍体出现率和胚胎存活率的关系,以及最佳条件下和不适条件下胚胎死亡的原因。

STUDIES ON GENOME MANIPULATION IN FISH I.INDUCTION OF TRIPLOID TRANSPARENT COLORED CRUCIAN CARP(CARASSIUS AURATUS TRANSPARENT COLORED VARIETY) BY HYDROSTATIC PRESSURE

This study was made to optimize hydrostatic pressure shock conditions for producing triploid transparent colored crucian carp (Carassius auratus transparent colored variety) by inducing second polar body retention. Shocks involving hydrostatic pressures of 600 kg/cm~2 and 650 kg/cm~2 for 3 minutes, applied 4 min or 5 min after fertilization, not only gave 100% triploidy as assessed by chromosome observation in the cells of embryos and fingerlings, but also produced relatively high rates of survival; the rates of hatching were about 90% relative to controls. Shocks applied at 6 min or later after fertilization had almost no effect on triploidization, and resulted in low survival rates. Shocks of hydrostatic pressures lower than 600 kg/cm~2 (550 kg/cm~2 or 500 kg/cm~2) for 3 minutes resulted in a small proportion of diploids. Shocks of hydrostatic pressures higher than 650 kg/cm~2 (700 kg/cm~2 or 750 kg/cm~2) for 3 minutes produced 100% triploidy but strongly affected the development of fertilized eggs, resulting in deformed embryos because of chromosome breakage and loss. The treatment of longer durations had the same effect as the treatment of higher pressures, which apparently disrupted the embryonic developmental processes. The longer the treatment duration, the higher the mortality. The results obtained from this study and those reported by other investigators seem to indicate that hydrostatic pressure shock may be an efficient method for performing chromosome set manipulation in fish, because the optimal conditions of hydrostatic pressure treatment are easy to obtain and the procedures of treatment are easy to standardize. The relationships between the optimal conditions and the percentage of triploidy as well as the survival rates were discussed. The causes for death under optimal and suboptimal conditions were analysed.