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Long-term preservation of silkworm eggs

蚕卵的长期保存

基本信息

批准号：
58860050
负责人：
YAMASHITA Okitsugu
金额：
$ 6.4万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1983
资助国家：
日本
起止时间：
1983 至 1985
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-58860050/
关键词：
silkworms eggs diapause diapause hormone 長期保存

项目摘要

It is desired in sericultural industry to preserve silkworm eggs more than two years. Long-term preservation of diapause type of eggs is assumed to prolong the diapause periods. For this, some attempts were done in view of endocrinonolgy, environmental physiology, biochemistty and genetics. Most significant effects on long-term preservation were obtained by direct transfer of the eggs into below 1゜C and maintenance at this temperature. These eggs remained at diapause state which is characterized by a high accumulation of sorbitol and a trace level of NAD-sorbitol dehydrogenase activity. The diapaude of these eggs were to be terminated by keeping at 5゜C for more than 2 months. Thus, the preservation of eggs closely depends on the chilling periods at 1゜C. Ehereas, non-diapause eggs were safely stored at 10゜C rather than 1゜C. However, dkapause hormone treatment on non-diapause egg producers brought about induction of diapause eggs and these eggs were preserved longer at 1゜C. To maintain diapause, some biochemical adaptation occurred; lipids in chorion, polyols in yolks and DNA and RNA in embryos. These metabolic shiftsare indispensably incorporated into the diapause physiology.Developing ovaries were sucessfully preserved in liwuid nitrogen, which maintain their ability to mature eggs in them and larval hatching from embryonated eggs after parthenogenic activation. Further, some grnetical charactors are shown to be included in sensitivity to chilling at 1゛C, suggesting that long-term preservation of silkworm eggs is also inproved by genetical selections.

蚕业要求蚕卵保存两年以上。长期保存滞育型卵被认为可以延长滞育期。为此，从内分泌学、环境生理学、生物化学和遗传学等方面进行了一些尝试。通过将卵子直接转移到1℃以下并在此温度下保存，可以获得对长期保存最显著的影响。这些卵保持滞育状态，其特征是山梨糖醇的大量积累和微量的nad1山梨糖醇脱氢酶活性。这些卵子将通过在5℃下保持2个月以上来终止受精。因此，鸡蛋的保存在很大程度上取决于1℃的冷藏时间。然而，非滞育卵在10ºC而非1ºC下安全保存。然而，对非滞育卵生产者使用滞育激素诱导滞育卵，这些卵在1 C下保存的时间更长。为了维持滞育，发生了一些生化适应；绒毛膜中的脂质，蛋黄中的多元醇，胚胎中的DNA和RNA。这些代谢变化是滞育生理不可缺少的组成部分。在液氮中成功保存了发育中的卵巢，保持了卵巢内成熟卵和孤雌激活后由胚胎卵孵化出幼虫的能力。此外，一些遗传特性也被包含在1 (C)下对低温的敏感性中，这表明蚕卵的长期保存也通过遗传选择得到了改善。