Phosphoinositide Signaling and Actin Polymerization Are Critical for Tip Growth in the Marine Red Alga <i>Pyropia yezoensis</i>.

ABSTRACT: In the marine red alga Pyropia yezoensis, filamentous phases of the life cycle, e.g., the conchocelis (sporophyte) and conchosporangium (conchosporophyte), proliferate by tip growth. In this study, we investigated the possible involvement of phosphoinositide turnover and actin polymerization in the spontaneous initiation and tip growth of new branches in isolated single-celled conchocelis cells using pharmacological treatments. Treatment with LY294002 and U73122, specific inhibitors of phosphoinositide-phosphate 3-kinase and phospholipase C, respectively, reduced side-branch formation and inhibited the elongation of branches. In addition, two inhibitors of the actin cytoskeleton, cytochalasin B (CCB) and latrunculin B (LAT-B), had similar effects on tip growth. However, CCB did not

SUBMITTER: Irie R 

PROVIDER: S-EPMC12299721 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature