An Integrative View on Multiple "Lipid Divide" Events as Hallmarks of Distinct Evolutionary Transitions.

Area of Science:

• Biochemistry
• Evolutionary Biology
• Cell Biology

Background:

• Lipids are essential molecules involved in membrane structure, signaling, energy storage, and cellular identity.
• The "lipid divide" between Bacteria and Archaea is a known evolutionary divergence.
• Emerging evidence indicates lipid-based divergences extend beyond prokaryotes.

Purpose of the Study:

• To highlight multiple lipid divergences coinciding with major phylogenetic splits across life.
• To propose an expanded model of the lipid divide as a recurring evolutionary hallmark.
• To offer insights into the molecular basis of cellular complexity and evolutionary innovation.

Main Methods:

• Mapping lipid class distribution across various lineages.
• Identifying lineage-specific lipid biosynthetic enzymes, regulatory proteins, and functional effectors.
• Correlating molecular players with phylogenetic divergences.

Main Results:

• Lipid divergences are observed at multiple phylogenetic levels, including unikont-bikont separation, Amoebozoa-Opisthokonta split, fungi-metazoa divergence, invertebrate-vertebrate transition, and intragenus divergence.
• These divergences are associated with the presence or absence of specific lipid-related genes and proteins.
• Lipid composition varies significantly across different evolutionary branches.

Conclusions:

• The "lipid divide" is not limited to prokaryotes but is a recurring theme in evolution across all domains of life.
• Lipid-centric evolutionary events contribute to cellular complexity and innovation.
• Further research is needed to uncover additional lipid divergence events and their evolutionary significance.