# Recombination plasticity in response to temperature variation in reptiles

## TL;DR

This study shows that temperature changes affect genetic recombination in geckos, increasing crossovers and altering meiotic processes.

## Contribution

The study reveals temperature-induced recombination plasticity in a non-model ectothermic species.

## Key findings

- High and low temperatures increased crossover frequency in gecko spermatocytes.
- Temperature changes were linked to shorter chromosome axis lengths and more meiotic DSBs.
- Results highlight the environmental influence on meiotic recombination in ectotherms.

## Abstract

The survival of species depends on their ability to adapt to environmental changes. While organisms are known to activate common transcriptional pathways in response to temperature variations, the impact of temperature on recombination, a key source of genetic variability, remains largely unexplored. Previous studies in model species have shown that the frequency of recombination during meiotic prophase I can be influenced by extreme temperatures. Yet, it remains unclear whether this effect is also conserved in non-model vertebrates. In this study, we investigated the effect of temperature on recombination in the Guibé’s ground gecko (Paroedura guibeae), an ectotherm species. We analyzed the formation of double-strand breaks (DSBs) and crossovers (COs) by immunolocalizing the meiotic proteins involved in these processes. Furthermore, we determined the frequency and chromosomal location of COs and the levels of CO interference (COI). Our findings show the presence of hyper-COs spermatocytes in individuals exposed to both high and low temperatures. Notably, this significant increase in COs was associated with a decrease in chromosome axis lengths and elevated levels of meiotic DSBs in later stages of prophase I. In conclusion, our results provide new insights into the effects of environmental temperatures on meiotic recombination in ectothermic species, underscoring the intricate interplay between environmental factors and genetic processes.

Species survival hinges on adapting to environmental changes. While organisms activate common genetic pathways in response to temperature shifts, the impact on recombination—a key source of genetic diversity—remains largely unexplored, especially in non-model vertebrates. Here we investigated how temperature affects recombination in the Guibé’s ground gecko, an ectothermic species. By analyzing proteins involved in double-strand breaks (DSBs) and crossovers (COs), we uncovered a significant increase in COs upon exposed to high and low temperatures, linked to shorter chromosome axis lengths and higher levels of meiotic DSBs. Our findings reveal the complex interplay between temperature and genetic processes in ectothermic species, offering new perspectives on how environmental factors shape genetic diversity.