# Genome-Wide Profiling of P450 Gene Expression Reveals Caste-Specific and Developmental Patterns in Solenopsis invicta

## TL;DR

This study explores how P450 genes are expressed in different stages and castes of fire ants, revealing their roles in development, reproduction, and social behavior.

## Contribution

The study identifies caste- and development-specific P450 gene expression patterns in Solenopsis invicta, linking them to physiological and social functions.

## Key findings

- CYP4, CYP6, and CYP9 genes are highly expressed in early larval stages and minim workers, supporting growth and colony maintenance.
- CYP4AA1 is overexpressed in queens and female alates, indicating its role in pheromone production and reproductive dominance.
- Halloween genes and CYP18A1 show dynamic regulation across stages, highlighting their roles in hormone production and balance.

## Abstract

P450 enzymes are integral to insect physiology, metabolism, hormone regulation, and adaptation to environmental challenges. By leveraging transcriptomic and genomic data, this study characterized the expression of 68 unique P450 genes across developmental stages and castes in the red imported fire ant (Solenopsis invicta), uncovering stage- and caste-specific differential expression patterns. Genes from the CYP4, CYP6, and CYP9 families, known for metabolizing exogenous and endogenous compounds, were highly expressed in early larval stages and minim workers, underscoring their roles in supporting rapid growth, hormone metabolism, colony maintenance, and brood care. The overexpression of CYP4AA1—linked to pheromone production—in queens, female alates, and female alate pupae highlights its critical functions in reproductive dominance, social structure maintenance, and colony dynamics. Here, juvenile hormone biosynthesis genes, including CYP305A1 and CYP315A1, exhibited significant overexpression in later instar larvae and larger workers, emphasizing their roles in development and in fulfilling colony-wide physiological demands. The “Halloween genes” (CYP302A1, CYP306A1, CYP315A1, CYP307A1, and CYP314A1) and CYP18A1 demonstrated dynamic regulation across developmental stages and castes, reflecting their essential contributions to hormonal production and balance throughout S. invicta’s lifecycle. These findings offer valuable insights into the molecular and biological mechanisms driving S. invicta’s social organization, developmental transitions, physiological adaptations, and evolutionary success. They also provide a foundation for future research into the regulatory pathways governing P450 gene expression and function.