2026-10-20 東京大学
頭足類における腕と吸盤の獲得
＜関連情報＞
- https://www.s.u-tokyo.ac.jp/ja/press/11248/
- https://www.cell.com/iscience/fulltext/S2589-0042(26)03142-1
頭足類吸盤の発生メカニズムと進化過程 Developmental mechanism and evolutionary process of cephalopod suckers
Ryosuke Kimbara ∙ Hisanori Kohtsuka ∙ Kohei Oguchi ∙ Daisuke Kurokawa ∙ Toru Miura
iScience Published:October 20, 2026
Highlights
- Cephalopods have appendage development mechanisms like animals with clear modules
- Appendage patterning genes are differently expressed in cephalopods and gastropods
- Suckers have specific formation and patterning mechanisms against the arm trunk
- Suckers are cephalopod innovations arising from the early embryonic gene co-option
Summary
In contrast to animals possessing clear modularity such as vertebrates and arthropods, the evolution of novel structures in animals with indistinct body modules, like molluscs, remains poorly understood. Among molluscs, cephalopods have unique arms and suckers, which are particularly notable because they show clear modularity despite their derivation from a simple flat foot of the ancestral molluscs. However, their developmental mechanisms and evolutionary processes have yet to be revealed. Gene expression analyses of cephalopod arms and gastropod feet showed that well-known appendage patterning genes in animals with clear modularity were expressed in cephalopod arms and gastropod feet but not in suckers. Instead, genes such as Ets1, typically involved in early embryonic processes like gastrulation in molluscs, were specifically expressed in suckers. These results suggest that cephalopod arms recruited developmental mechanisms similar to segmented appendages, whereas suckers represent a cephalopod-specific innovation formed through the co-option of genes contributing to early embryogenesis.
