Tissue-like multicellular development triggered by mechanical compression in archaea

Area of Science:

• Evolutionary biology
• Microbiology
• Biophysics

Background:

• Clonal multicellularity is a rare evolutionary event, observed predominantly in eukaryotes.
• Archaea have a limited history of developing multicellularity, with only one known instance.
• Understanding the emergence of multicellularity across different domains of life is crucial.

Purpose of the Study:

• To investigate the induction of clonal multicellularity in haloarchaea.
• To characterize the mechanical and molecular properties of archaeal tissues.
• To explore the potential for convergent evolution in multicellular systems.

Main Methods:

• Induction of multicellularity via uniaxial compression in haloarchaea.
• Mechanical and molecular analysis of archaeal tissues.
• Microscopy and cellular analysis to identify cell types and developmental stages.

Main Results:

• Uniaxial compression successfully induced clonal multicellularity in haloarchaea, forming tissue-like structures.
• Archaeal tissues exhibit distinct mechanical and molecular properties compared to unicellular haloarchaea, mimicking eukaryotic features.
• A tubulin-independent cellularization process, driven by membrane tension at a critical cell size, was observed.
• Two distinct cell types, peripheral (Per) and central scutoid (Scu) cells, emerged with specialized polarity patterns.

Conclusions:

• Haloarchaea can form multicellular tissues under specific biophysical conditions (uniaxial compression).
• The study reveals a potential convergent evolutionary pathway for multicellularity, driven by biophysical mechanisms.
• These findings challenge the traditional view of multicellularity's exclusivity to eukaryotes and bacteria.