Cooperative motility, force generation and mechanosensing in a foraging non-photosynthetic diatom

Open Biol. 2023 Oct;13(10):230148. doi: 10.1098/rsob.230148. Epub 2023 Oct 4.


Diatoms are ancestrally photosynthetic microalgae. However, some underwent a major evolutionary transition, losing photosynthesis to become obligate heterotrophs. The molecular and physiological basis for this transition is unclear. Here, we isolate and characterize new strains of non-photosynthetic diatoms from the coastal waters of Singapore. These diatoms occupy diverse ecological niches and display glucose-mediated catabolite repression, a classical feature of bacterial and fungal heterotrophs. Live-cell imaging reveals deposition of secreted extracellular polymeric substance (EPS). Diatoms moving on pre-existing EPS trails (runners) move faster than those laying new trails (blazers). This leads to cell-to-cell coupling where runners can push blazers to make them move faster. Calibrated micropipettes measure substantial single-cell pushing forces, which are consistent with high-order myosin motor cooperativity. Collisions that impede forward motion induce reversal, revealing navigation-related force sensing. Together, these data identify aspects of metabolism and motility that are likely to promote and underpin diatom heterotrophy.

Keywords: force generation; gliding motility; heterotrophy; mechanosensing; non-photosynthetic diatom.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria
  • Diatoms* / physiology
  • Ecosystem
  • Extracellular Polymeric Substance Matrix
  • Photosynthesis

Associated data

  • figshare/10.6084/m9.figshare.c.6836749