# Evolution of the Genome-wide Recombination Rate in Mice

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 2020 · $590,376

## Abstract

PROJECT SUMMARY
Recombination during meiosis serves multiple biological roles. Recombination diversifies genomes by shuffling
combinations of mutations, thereby increasing genetic variation and enhancing the efficiency of natural
selection. In many species, recombination also ensures that chromosomes segregate properly during
gametogenesis. Although these roles should impose strong selective constraints on recombination,
recombination rate varies among individuals. This unexpected result raises a major unanswered question:
what processes govern variation in recombination rate in nature?
Importantly, we still lack a basic picture of how the heritable component of recombination rate varies within and
between species – information that is required for understanding how any phenotype evolves. Two clues about
potential determinants of natural variation come from recent studies targeting recombination mechanisms.
First, the two sexes present contrasting recombination landscapes and meiotic constraints, raising the
prediction that males and females will display discordant patterns of inter-individual variation. Second, there is
new evidence that the number of DNA double-strand breaks and the proportion of breaks repaired as
crossovers also show differences among individuals, suggesting that these traits could explain natural variation
in recombination rate.
The proposed research will provide a much-needed portrait of natural genetic variation in recombination rate
across multiple evolutionary scales. The contributions of sex and key meiotic processes to variation in
recombination rate among individuals will be evaluated. In Aim 1, we will measure polymorphism and
divergence in the genome-wide recombination rate during oogenesis and spermatogenesis by applying
immunofluorescence cytology to individual mice. Sex-specific, genetic variation in the total number of
crossovers will be quantified on geographically global and local scales using a panel of house mice and their
relatives. The prediction that recombination rate experiences distinctive evolutionary pressures in the two
sexes will be tested through controlled comparisons between females and males across common genomic
backgrounds. In Aim 2, we will use immunofluorescence cytology to profile natural genetic variation in
molecular processes that lead to crossovers, including the generation of double-strand breaks, the regulation
of recombination intermediates, and the assembly of the synaptonemal complex. By linking these traits to the
total number of crossovers in the same set of strains, we will test the hypothesis that the decision between
crossover and non-crossover repair is a primary factor in recombination rate evolution.
Defects in recombination are a leading cause of fetal loss and a leading genetic cause of developmental
disabilities in humans. By examining heritable variation in recombination rate and its potential determinants in
natural populations of the house mouse – a model organism fo...

## Key facts

- **NIH application ID:** 9896869
- **Project number:** 5R01GM120051-04
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Bret A Payseur
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $590,376
- **Award type:** 5
- **Project period:** 2017-05-15 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9896869

## Citation

> US National Institutes of Health, RePORTER application 9896869, Evolution of the Genome-wide Recombination Rate in Mice (5R01GM120051-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9896869. Licensed CC0.

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