Ecological Niche Adaptations Influence Transposable Element Dynamics in Pollinating and Non-Pollinating Fig Wasps

Area of Science:

• Genomics
• Evolutionary Biology
• Ecology

Background:

• Transposable elements (TEs) are mobile genetic sequences influencing genome evolution.
• Fig wasps exhibit diverse ecological roles, including pollination and seed predation, potentially impacting their genomic landscapes.
• Understanding TE dynamics in relation to ecological niches can reveal adaptive evolutionary processes.

Purpose of the Study:

• To investigate the influence of ecological niches, specifically oviposition sites, on transposable element (TE) dynamics in pollinating and non-pollinating fig wasps (NPFWs).
• To compare TE load, types, and dynamics between pollinating and NPFWs to understand genome evolution.
• To assess the role of TEs in adaptation by examining their proximity to regulatory genes.

Main Methods:

• Comparative analysis of TE load and dynamics in six pollinating and five NPFW species.
• Phylogenetic analysis to correlate genome size, oviposition sites, and TE length.
• Analysis of natural selection and population dynamics' effects on TE accumulation.

Main Results:

• Significant differences in TE length, number, and types were found between pollinators and NPFWs.
• NPFWs exhibit expanding TEs driven by genome size and oviposition sites, whereas pollinators display limited TE insertions ('dormant' landscape).
• TEs contribute cis-regulatory modules near genes involved in environmental information processing, suggesting a role in adaptation.

Conclusions:

• Ecological niches, particularly oviposition sites, are key drivers of TE dynamics in fig wasp genomes.
• Pollinators maintain low TE abundance despite relaxed selection, likely due to contracted population sizes.
• TEs play a significant role in insect adaptation through the regulation of environmental response genes.