抄録
Our previous experiment using a trehalase inhibitor, trehazolin, indicated the possibility that the diapause hormone (DH) could induce embryonic diapause through a regulating expression of some genes other than the trehalase gene in developing ovaries of the silkworm, Bombyx mori. To examine this possibility, we employed the differential display after a DH challenge. We identified three cDNA fragments (ID1, ID3, UP3) in which expression was up-regulated by DH. ID1, ID3, UP3 and trehalase mRNA were detected at different levels in all tissues examined, but only the developing ovary responded positively to a DH challenge. DH induced the gene expression at a high level in the vitellogenic or younger follicles. ID1, ID3 and UP3 gene expression was significantly stimulated as early as 30min after DH administration and reached a maximum level at 1h. By contrast, the trehalase gene was slowly up-regulated. Actinomycin D completely inhibited DH-dependent stimulation of the expression, whereas cycloheximide did not inhibit the expression. Thus, DH is conceived to act on one organ to regulate the expression of different genes through different mechanisms.
