How does multicellularity develop?

A bacterial inhibitor could shed light on the development of multicellularity in choanoflagellates

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A woman in a lab coat stands in a laboratory holding up two bottles of yellowish liquid.
Chia-Chi Peng is one of the two first authors of the paper. Source: Anna Schroll/Leibniz-HKI

The unicellular marine organism Salpingoeca rosetta belongs to the group of choanoflagellates. When hunting for bacteria, these protozoa can detect their prey by means of certain signaling molecules. They then form rosette-like multicellular structures to better catch their prey. However, some bacteria produce inhibitors to prevent the formation of the rosette shape and thus protect themselves against the predators.

Scientists from the Leibniz-HKI Research Unit Chemical Biology of Microbe-Host Interactions have now chemically synthesized this bacterial inhibitor, the sulfonolipid IOR-1A. The short, modular synthesis route also allowed them to produce functionalized derivatives, the effect of which on thechanoflagellate S. rosetta was also assessed. The experiments were in collaboration with the Molecular and Applied Microbiology and the Biosynthetic Design of Natural Products units of the Leibniz-HKI, as well as with the University of California at Berkeley, USA.

Microscopic image, light microscopy above, fluorescence microscopy below.
Light and fluorescence micrograph of choanoflagellates. The fluorescence image shows the uptake of the sulfonolipid (blue). Source: Chia-Chi Peng/Leibniz-HKI

The studies have allowed "elaboration of the biochemical foundations of rosette-formation in the choanoflagellate S. rosetta," the authors write in the journal Angewandte Chemie. In further steps, they want to investigate the exact role of the detected target proteins in cell differentiation of S. rosetta in order to decipher the cellular signaling pathways.

Choanoflagellates are considered the closest living unicellular relatives of today’s animals and have become an important model organism to study the evolution of multicellularity.

Original publication

Raguž L, Peng CC, Rutaganira FUN, Krüger T, Stanišić A, Jautzus T, Kries H, Kniemeyer O, Brakhage AA, King N, Beemelmanns C (2022). Total Synthesis and Functional Evaluation of IORs, Sulfonolipid-based Inhibitors of Cell Differentiationin Salpingoeca rosetta. Angew. Chem. Int. Ed. 2022, e202209105


Christine Beemelmanns
Axel A. Brakhage
Theresa Jautzus
Olaf Kniemeyer
Hajo Kries
Thomas Krüger
Chia-Chi Peng
Luka Raguž
Aleksa Stanišić