# Genetic Basis of Cuticular Hydrocarbon Variation in the Desert Ant Cataglyphis niger

## TL;DR

This study explores the genetic basis of cuticular hydrocarbon variation in desert ants and finds multiple genetic regions linked to these chemical signals.

## Contribution

The paper identifies 20 QTLs associated with cuticular hydrocarbon variation in Cataglyphis niger, revealing a polygenic basis for chemical signaling in social insects.

## Key findings

- 19 QTLs are associated with 8 out of 31 identified cuticular hydrocarbons.
- One QTL is linked to total cuticular hydrocarbon quantity.
- Candidate genes like fatty acid elongase and reductase are highlighted in the QTLs.

## Abstract

Cuticular hydrocarbons (CHCs) are a ubiquitous component of insect cuticles that are used for a wide range of chemical signaling functions, especially recognition. Recognition and other signals are vital for the maintenance of insularity and cooperation in social insect colonies. Therefore, we expect natural selection on the composition and variability of social insect CHC profiles. Selection on these signals may result in the evolution of genetic polymorphism affecting variation in CHC profiles. Here we tested for a genetic basis of CHC variation in the desert ant
Cataglyphis niger
. We applied a genomic mapping approach to a cohort of brothers from the same nest to reduce noise from environmental effects and achieve a clear statistical signal for association between the variation of CHCs and quantitative trait loci (QTL). This analysis identified 19 QTLs associated with 8 out of the 31 CHCs identified, and one QTL associated with total CHC quantity. These QTLs are located on 11 different chromosomes, including two cases where QTLs of different CHCs overlap. Each QTL explains between 13%–25% of the variation in a specific CHC. We highlight several candidate genes in the QTLs identified, including fatty acid elongase and reductase genes. Our results reveal a polygenic genomic architecture underlying CHC variation in a population of the desert ant and open new research avenues into the genetic basis and evolution of chemical signaling in social insects.

Cuticular hydrocarbons (CHCs) are a ubiquitous component of ant cuticles that are used for a wide range of chemical signaling functions, especially recognition. Here we tested for a genetic basis of CHC variation in the desert ant
Cataglyphis niger
. We applied a genomic mapping approach to discover associations between CHCs and 20 quantitative trait loci (QTL).