2026-05-18 早稲田大学
図1 卵子周囲の細胞から卵子に向けて伸びる突起のほとんどに微小管が含まれていることを発見
＜関連情報＞
- https://www.waseda.jp/inst/research/news/84436
- https://www.cell.com/iscience/fulltext/S2589-0042(26)01286-1
Camsap3を介した微小管は、マウスの卵胞成熟中に体細胞と生殖細胞間のコミュニケーションに不可欠な細胞間突起を維持する Camsap3-mediated microtubules maintain transzonal projections essential for soma–germ communication during ovarian follicle maturation in mice
Akihiro Aikawa ∙ Takao Tsurumaki ∙ Erina Kuranaga ∙ Junya Ito ∙ Mika Toya ∙ Masamitsu Sato
iScience Published:April 28, 2026
DOI:https://doi.org/10.1016/j.isci.2026.115911
Highlights
- Most TZPs contain microtubules at their base, with some extending along the F-actin
- TZP morphology changes during follicle development
- Camsap3-mediated microtubules maintain the TZP number and architecture
- Camsap3 contributes to the production of fertile oocytes through follicle development
Summary
Oocytes are surrounded by layers of maternal somatic granulosa cells (GCs) in ovarian follicles. GCs extend actin-containing transzonal projections (TZPs) to oocytes across the zona pellucida to establish communication. Microtubules have rarely been observed in TZPs, and their significance in TZP organization and follicular maturation remains unknown. Here, using super-resolution microscopy, we visualized microtubules alongside F-actin in most TZPs. Knockout (KO) mice of the microtubule minus-end binding protein Camsap3 (calmodulin-regulated spectrin-associated protein 3) exhibited infertility without ovulation despite normal estrous cycles. Ovaries of Camsap3-KO mice contained fewer developing follicles, particularly of antral and Graafian stages. In earlier stages of Camsap3-KO follicles, TZP numbers were reduced compared to wild-type follicles, and microtubules in TZPs were disorganized, leading to decreased contact between GCs and oocytes. TZP morphology in wild-type transforms during follicle development, and Camsap3-mediated microtubules govern the number and morphology of TZPs, contributing to successful follicle development for fertile oocyte production.
