Molecular mechanisms for apyrene sperm differentiation

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21299
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 39:Agricultural and environmental biology and related fields
• Research Institution: Hirosaki University
• Principal Investigator: Kaneko Yu 弘前大学, 農学生命科学部, 准教授 (90633610)
• Co-Investigator(Kenkyū-buntansha): 佐原 健 岩手大学, 農学部, 教授 (30241368)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 精子形成 / カイコ

Outline of Final Research Achievements

In lepidopteran testis, two types of sperms are produced. One type of sperm is eupyrene sperm that has a nucleus, and the other is apyrene sperm which lacks a nucleus. The eupyrene sperm are involved in normal fertilization, while apyrene sperm have assisting roles which are necessary for fertilization. Both types of sperm are produced in the same follicle of testis, while the differentiation of both types are different stages. Eupyrene sperms differentiate during last larval stage followed by apyrene sperm differentiation. The mechanisms of switchover induction from eupyrene sperm production to apyrene sperm production are not fully elucidated. In the present study, we showed that insect hormones play a critical role on the switchover.

Free Research Field

昆虫生理学

Academic Significance and Societal Importance of the Research Achievements

チョウ目昆虫は進化の過程で、遺伝物質を持たない無核精子を作るようになった。なぜこのように進化してきたのか？無核精子形成の分子機構を解明することは、チョウ目昆虫における進化、種分化を考える上で大きな役割を果たし得る。一方で、チョウ目昆虫は多くの農業害虫が属する分類群である。無核精子は受精に必須であることから、その形成機構を明らかにすることは、チョウ目の生殖を選択的に制御する全く新しい害虫防除技術への貢献が期待できる。