Long-term preservation of silkworm eggs

这是一种描述在序列工业中要保留silkworm再多两个years. Long-termpreservation of diapause type of eggs is assumed to prolong the diapause periods. For this，some attempts were done in view of endocrinonolgy，环境physiologybiochemistty and genetics. Most significant effects on long-term preservation were tained bydirect transfer of the eggs into below 1 C and maintenance at this temperature.这些eggs remainedat diapause state which is characterized by a high accumulation of sorbitol and a trace level ofNAD-sorbitol dehydrogenase activity. The diapaude of these eggs to be terminated by keeping atC for more than 2 months. Thus，the preservation of eggs closely depends on the chilling periods at 1 C. Ehereasnon-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 eggsand这些eggs were preserved longer at 1 C. To maintain diapause，some biochemical adaptation occurredlipids in chorion，polyols in yolks and DNA and RNA in embryos. These metabolic shiftsare indispensably incorporatedinto 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 afterparthenogenic activation. Further，some grnetical charactors应该包含在sensitivity to chilling at 1 ` C，suggesting that long-term preservation of silkworm eggs也是遗传选择。

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.