# The prevalence of genetic introgression in speciation

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2020 · $314,798

## Abstract

Background: The importance of genetic exchange between species (i.e. introgression of genes from one
species into another through hybrid intermediates) is a constant subject of debate among evolutionary
biologists. While some claim genetic exchange is pervasive, others claim that it is extremely rare. Currently,
there is little data quantitatively supporting either of these scenarios.
Broad, long-term objective: The proposed study of naturally occurring hybrid zones will quantify the
prevalence of genetic exchange between species to understand the frequency and evolutionary consequences
of gene exchange. The proposal takes advantage of these natural experiments in hybrid zones to find admixed
genomes with which I can map the genetics of complex behavior traits that differ between the hybridizing
species. Since genetic mapping of behavior traits has proven very difficult by conventional means, admixture
mapping provides a unique opportunity to make progress on these important questions.
Specific aims: Aim 1 of the study is to map the prevalence of introgression in six natural hybrid zones, four of
which are documented here for the first time. Aim 2 will used admixed flies from a hybrid zone to map genes
underlying the ecologically important trait of temperature preference. Aim 3 will use admixed flies from another
hybrid zone to map genes underlying the complex behavioral trait of mate preference.
Method: Fruit flies from the genus Drosophila can be collected in their natural habitat and also maintained
under laboratory conditions, and have an unmatched arsenal of molecular genetic and genomic tools. This
proposal presents a novel model for identifying introgressed alleles in the genome, an approach that is only
feasible in hybridizing organisms for which both parental species have high quality genome assemblies. The
genes identified in these admixture analyses will be functionally validated with CRISPR-mediated gene
replacements. Preliminary results for admixture mapping and genome editing are both promising.
Health-relatedness: Admixture mapping in humans is a primary approach used for the identification of
disease-causing gene variants. However, follow up experiments to test the function of genes correlated with
disease cannot be performed in humans. Admixture mapping protocols have therefore never been validated
end-to-end from the population level at which variants correlated with disease are identified, to the functional
molecular genetic level where the phenotypic state is manifested. This proposal is innovative because it
develops new computational methods to identify genomic regions with complex ancestry, and then connects
these genomic patterns to measurable phenotypic differences via genome editing.
Impact: The results from this study will provide the first broad view of patterns of introgression in cases where
species interbreed in nature, and will leverage those patterns of admixture to dissect the genetic basis of
behavioral differen...

## Key facts

- **NIH application ID:** 9978075
- **Project number:** 5R01GM121750-04
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Daniel Matute
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $314,798
- **Award type:** 5
- **Project period:** 2017-09-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9978075

## Citation

> US National Institutes of Health, RePORTER application 9978075, The prevalence of genetic introgression in speciation (5R01GM121750-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9978075. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*