Molecular mechanism of induction of embryonic diapause in Bombyx mori

2015 Fiscal Year Final Research Report

• Project/Area Number: 24380031
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Applied entomology
• Research Institution: Shinshu University
• Principal Investigator: SHIOMI Kunihiro 信州大学, 学術研究院繊維学系, 准教授 (70324241)
• Co-Investigator(Kenkyū-buntansha): MIZOGUCHI Akira 愛知学院大学, 教養部, 教授 (60183109) ; OHTA Hiroto 熊本大学, 自然科学研究科, 助教 (60450334) ; SHIRAI Koji 信州大学, 学術研究院繊維学系, 准教授 (00293499) ; NAKANISHI Hiromitsu 信州大学, サテライト・ベンチャー・ビジネス・ラボラトリー, 助教 (90443001)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: カイコ / 温度センサー / RNA-seq. 解析 / 休眠ホルモン

Outline of Final Research Achievements

In the bivoltine strain of the silkworm, Bombyx mori, embryonic diapause is induced transgenerationally as a maternal effect. Progeny diapause is determined by the environmental temperature during embryonic development of the mother; however, its molecular mechanisms are largely unknown. Here, we show that the Bombyx TRPA1 ortholog (BmTrpA1) acts as a thermosensitive transient receptor potential (TRP) channel that is activated at temperatures above ~21°C and affects the induction of diapause in progeny. In addition, we show that embryonic RNAi of BmTrpA1 affects diapause hormone release during pupal-adult development. Furthermore, we searched the candidate genes participating in diapause induction. This is the first study to identify a thermosensitive TRP channel that acts as a molecular switch for a relatively long-term predictive adaptive response by inducing an alternative phenotype to seasonal polyphenism.

Free Research Field

環境分子昆虫学、蚕糸科学