# Molecular and Evolutionary Genetics of Meiotic Drive

> **NIH NIH R01** · CORNELL UNIVERSITY · 2020 · $320,921

## Abstract

Project Summary/Abstract
Mendel's first law describes how the two alleles in a heterozygous individual have equal chances of being
transmitted to its progeny. Decades of work have revealed that different types of selfish DNAs can parasitize
host species and subvert Mendel's first law to increase their transmission to offspring and their frequency in
populations. These selfish DNAs are deleterious as they can reduce fertility and distort allele frequencies of
host genes in populations. The asymmetric meiosis found in the females of many species including humans is
particularly prone to attack by selfish DNAs because only one meiotic product forms an egg while the
remainder become polar bodies. Meiotic drivers exploit this asymmetry by biasing their transmission to the
egg. Moderate-strength meiotic drivers that bias their transmission by a few percent may be prevalent in
populations but have been challenging to identify due to the necessity of distinguishing them from viability
effects. This proposal will determine the identity and mechanism of a recently discovered candidate meiotic
driver discovered in a natural population of the fruit fly Drosophila melanogaster that causes an approximately
4% deviation from normal Mendelian segregation. This candidate maps broadly to a centromeric region,
leading to the working hypothesis that it corresponds to a variant in heterochromatic repetitive DNA. Novel
methods will first be used to track the genotype and state of development of individuals throughout the life
cycle, from meiosis in their mothers through adulthood, in order to determine the mechanism of meiotic drive.
Heterochromatic regions have long been considered inaccessible to conventional genetic mapping approaches
due to their complete suppression of meiotic recombination. A new approach is developed here to generate
recombinants across the centromeric region in order to perform a high-resolution association study of repeat
type and abundance relative to meiotic drive. Importantly, this approach does not require genome assembly
across the centromere. We will also apply both short-read and long-read sequencing technologies to identify
candidate sequences responsible for drive. Following these mapping and sequencing approaches,
experimental manipulation will be used to test and confirm identity of the meiotic driver. Evolutionary theory
predicts that meiotic drive will vary in degree between populations. This proposal will investigate the magnitude
of drive in both related and unrelated populations, and then map and identify major-effect modifier alleles.
Other candidate meiotic drivers will also be characterized by the approaches developed here. This proposal
will provide an unprecedented level of information about the identity and mechanism of meiotic drivers that are
segregating in natural populations, and provide a framework and series of methods that can be applied to other
types of non-Mendelian transmission in a wide range of organisms.

## Key facts

- **NIH application ID:** 9850974
- **Project number:** 5R01GM074737-14
- **Recipient organization:** CORNELL UNIVERSITY
- **Principal Investigator:** DANIEL A BARBASH
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $320,921
- **Award type:** 5
- **Project period:** 2019-01-16 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9850974

## Citation

> US National Institutes of Health, RePORTER application 9850974, Molecular and Evolutionary Genetics of Meiotic Drive (5R01GM074737-14). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/9850974. Licensed CC0.

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