BIOLOGICAL ASPECTS OF RESTING EGG DIAPAUSE AND HATCHING AND ITS APPLICATION TO MASS PRESERVATION TECHNOLOGY

研究了海洋轮虫褶皱臂尾轮虫休眠卵的滞育和孵化。胚胎内滞育期的核总数从产卵后第2天的22个增加到第6天的39个(每个n=1)，胚膜外层从1.2(第0天)逐渐增厚到4.0微米(第8天)(每个n=10)。350 nm以上光照孵化率为1-25%，250-310 nm光照孵化率为50-60%。加入过氧化氢或前列腺素(E1、E2或F2α)，即使在黑暗中也能使休眠卵子孵化。光照引起的海水中过氧化氢的产生以及胚胎内脂肪酸氧化为前列腺素是休眠卵孵化的可能机制。由于细菌感染多孔卵表面，大量生产的休眠卵(在4ﾟC的黑暗海水中储存)的孵化率逐渐下降。当分压小于88kpa时，6个月后的孵化率在16%~20%之间，与未罐装的鸡蛋相似(19%)，但在88kpa和101kpa的条件下显著降低(9%和11%)。即使在12个月后，当罐装温度为61kpa时，孵化率仍保持在35%。用NaClO(1ppm)或NFS-Na(5ppm)处理的罐头鸡蛋的孵化率(分别为68%和80%)显著高于未处理的鸡蛋。

Diapause and hatching of the marine rotifer Brachionus plicatilis Muller resting eggs were examined. The total number of nuclei in an embryo during the internal diapause period increased from 22 on Day 2 post spawn to 39 (each n=1) on Day 6. The outer layr of embryo membrane gradually thickens from 1.2 (Day 0) to 4.0 mum (Day 8) (each n=10). Irradiation at more than 350 nm caused 1-25% hatching, but it reached 50-60% at 250-310nm light. The addition of hydrogen peroxide or prostaglandins (E1, E2 or F2 alpha) caused resting egg hatching even in darkness. The production of peroxide in seawater caused by light as well as the oxidation of fatty acid to prostaglandins inside the embryo is a possible mechanism of resting egg hatching.The hatchability of mass produced resting eggs (stored in sea water under the dark at 4ﾟC) gradually decreased due to bacterial infection of the porous egg surface. The canning method preserves eggs in a dry form, after lyophilization at -40oC.When partial pressures were less than 88 kPa, percent hatching after 6 months ranged between 16 and 20%, similar to that of uncanned eggs (19% hatching), but significantly lower (9 and 11%) at 88 and 101 kpa. Even after 12 months, percent hatching remained at 35% when canning was at 61 kpa. Canned eggs that were treated with NaClO (1ppm) or NFS-Na (5ppm) showed a significantly higher percent hatching (68% and 80%, respectively) than untreated eggs.