Analysis of the effect of cytoplasmic streaming on organelle positioning during early embryogenesis

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06681
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44020:Developmental biology-related
• Research Institution: Kwansei Gakuin University
• Principal Investigator: Kimura Kenji 関西学院大学, 生命環境学部, 講師 (40644505)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 細胞質流動 / 初期発生 / 極性形成 / 受精卵 / キネシン / 核配置

Outline of Final Research Achievements

Cytoplasmic streaming, the collective flow of the cytoplasm, occurs in the fertilized eggs of many animals. There are multiple types of cytoplasmic streaming. However, the role of each type of cytoplasmic streaming is poorly understood. In this study, the effect of cytoplasmic streaming, in which the direction of flow changes stochastically, on the development of C. elegans zygotes was analyzed. We found that sperm-derived pronucleus/centrosome complex (SPCC) drifted dynamically through cytoplasmic streaming after fertilization. Some of the SPCC were pushed away to the opposite side of the sperm entry point by cytoplasmic streaming, resulting in the reversal of the anterior-posterior polarity of the embryo. These results indicate that the stochastic behavior of cytoplasmic streaming contributes to the determination of cell polarity.

Free Research Field

発生生物学

Academic Significance and Societal Importance of the Research Achievements

需要が高まり続ける体外受精の分野では、活発な細胞質の流れ（細胞質流動）を示す受精卵の発生成功率が高いことから、正常に発生する質の高い卵を選別する上での非侵襲的な指標として細胞質流動が注目されている。しかし、具体的にどのような流れが何のために必要なのか未だ不明な部分が多く、指標としては不十分である。本研究により、線虫受精卵において細胞質流動の流れる向きが精子由来の核の配置を変えることで発生過程に重要な体軸の決定に影響することが初めて明らかになった。今回の成果により、卵の発生過程に細胞質流動が及ぼす効果の理解が進み、正常に発生する卵を見分ける上で細胞質流動が重要な指標となりうることが支持された。