||Genome-wide microarray screening for Bombyx mori genes related to transmitting the determination outcome of whether to produce diapause or nondiapause eggs
Akitomo, Shion ,
Egi, Yuichi ,
Nakamura, Yuki ,
Suetsugu, Yoshitaka ,
Oishi, KatsutakaSakamoto, Katsuhiko
193 , 2017-04 , Wiley / Institute of Zoology, Chinese Academy of Sciences
The bivoltine silkworm Bombyx mori (Lepidoptera: Bombycidae) exhibits a maternally controlled embryonic diapause. Maternal silkworms decide whether to lay diapause or non-diapause eggs depending on environmental factors such as the temperature and photoperiod during the egg and larval stages, and then induce diapause eggs during the pupal stage. However, little is known about the molecular mechanism that conveys the outcome of whether to produce diapause or non-diapause eggs from the egg or larval stages to the pupal stage. The present study used microarray analysis to investigate differentially-expressed genes in the larval brains of diapause- and non-diapause-egg producers, to which bivoltine silkworms were destined by thermal or photic stimulation during the egg stage. The cytochrome P450 18a1 and Krüppel homolog 1 genes were upregulated in producers of diapause eggs compared with those of non-diapause eggs under both experimental conditions. Cytochrome P450 18a1 encodes a key enzyme for steroid hormone inactivation and Krüppel homolog 1 is an early juvenile hormone-inducible gene that mediates the repression of metamorphosis. The upregulation of these genes during the larval stage might be involved in the signaling pathway that transmits information about the diapause program from the egg stage to the pupal stage in the silkworm.