抄録
To further understand the function of Samui protein which is a member of the BAG-protein family, the temporal profiles of mRNAs for the cold-inducible genes, Samui and sorbitol dehydrogenase (SDH), were examined in Bombyx diapause eggs exposed to 5, 0 and -10°C after incubation at 25°C for 30 days after oviposition Incubation at 5°C activated the expression of both genes, incubation at 0°C activated only the Samui gene, and incubation at -10°C did not activate the expression of either gene. Although incubation at 0°C was less effective for the termination of diapause than at 5°C, from about half of the eggs that had been incubated at 0°C for 250 days, larvae hatched within 60 days after being transferred to 25°C. This changing profile in the hatching ability appears to be correlated with the amount of Samui mRNA. These results are consistent with a proposal from a previous study which stated that the Samui protein may play a role in transmitting the signal from low temperatures, such as 5 and 0°C, to a downstream cascade in a diapause egg. In addition, a possible strategy for the long-term preservation of Bombyx eggs was discussed.
