# Sex differences in crossover interference in house mice

## TL;DR

This study finds that male house mice have stronger crossover interference than females during meiosis, shedding light on sex differences in genetic recombination.

## Contribution

The paper provides the first estimate of non-interfering crossovers in female mice and confirms stronger interference in males.

## Key findings

- Crossover interference is stronger in male meiosis compared to female meiosis in house mice.
- The proportion of non-interfering crossovers is lower in females than in males.
- Interference strength varies with chromosome length but not with crossover frequency.

## Abstract

Meiotic recombination ensures the fidelity of chromosome segregation in most organisms with sexual reproduction. The distribution of crossovers along chromosomes is governed in part by interference, which prevents multiple crossovers from occurring in close proximity, though not all crossovers are subject to interference. Neither the factors that control the strength of interference, nor the extent to which they vary within and between species, are well understood. Here, I confirm that crossover interference is stronger in male than in female meiosis in house mice (Mus musculus), provide the first estimate of the proportion of non-interfering crossovers in female mice, and show that this proportion is lower than in males. Interference is stronger on shorter chromosomes in both sexes, but the frequency of non-interfering crossovers is similar across the range of chromosome size. Together with evidence that interference varies across strains and subspecies, my results provide a foundation for studying the evolution and sexual dimorphism in this important feature of meiosis in mice.