Cold adaptation and horizontal gene transfer shape Antarctic sponge microbiomes

Area of Science:

• Marine Microbiology
• Ecology
• Evolutionary Biology

Background:

• Marine sponges host diverse, vital microbiomes across various global environments.
• Antarctic sponges harbor unique microbial communities adapted to extreme cold.
• Functional differences in Antarctic sponge microbiomes remain largely unexplored.

Purpose of the Study:

• Investigate functional differences in Antarctic sponge microbiomes compared to other environments.
• Focus on cold adaptation functions within these microbiomes.
• Assess the role of horizontal gene transfer (HGT) in driving functional adaptations.

Main Methods:

• Comparative analysis of functional gene content in Antarctic, temperate, and tropical sponge microbiomes.
• Identification of genes associated with cold adaptation.
• Assessment of horizontal gene transfer prevalence and mechanisms (e.g., conjugation, ICEs).

Main Results:

• Antarctic sponge microbiomes show higher proportions of cold adaptation genes (e.g., cold shock proteins, chaperones, osmoprotectants).
• Horizontal gene transfer (HGT) is prevalent in Antarctic sponge symbionts, contributing to metabolic functions and cold adaptation.
• The cold shock protein C (CspC) was identified as a potential horizontally acquired gene exclusive to Antarctic sponge symbionts.

Conclusions:

• Antarctic sponge microbiomes exhibit enhanced cold adaptation through functional genes facilitated by HGT.
• HGT mechanisms are evolutionarily significant in shaping microbial symbioses in extreme environments.
• Further research into HGT dynamics and specific symbionts can illuminate microbial evolution and host-symbiont interactions in polar ecosystems.