# Discovery and functional analysis of novel candidate genes and variants underlying craniofacial diversification in Cyprinodon pupfishes

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA BERKELEY · 2024 · $428,985

## Abstract

Project Summary:
Craniofacial abnormalities are the most common form of human birth defect, but their molecular basis remains
poorly understood. Highly conserved craniofacial developmental pathways shared across diverse vertebrate
species have been shaped by adaptive evolution to produce a tremendous diversity of adaptive craniofacial
phenotypes. Fundamental investigation of the genetic basis of these phenotypes will lead to better diagnosis,
prevention, and treatment of human birth defects. Indeed, complementary or new information on the genetic
basis of many human pathologies can be obtained from naturally occurring organisms, particularly non-model
vertebrates, that display analogous divergent phenotypes, known as ‘evolutionary mutant’ models. These natural
systems are becoming increasingly tractable for genomic and transgenic approaches and provide an opportunity
for ‘evolutionary’ forward genetics.
 Here I propose to build on my lab’s demonstrated success developing a new vertebrate system studying
the genetic basis of highly divergent craniofacial morphology in Caribbean pupfishes. Pupfish exhibit novel
craniofacial features not found in other non-model fish systems and are highly tractable for laboratory studies
with life histories and eggs comparable to zebrafish. Ongoing gene flow and strong selection for divergent
craniofacial features provide an ideal natural ‘experiment’ for fine-mapping candidate variants associated with
these traits. Our initial success confirming three new craniofacial genes in Caribbean pupfishes and identifying
27 candidate craniofacial genes found in other vertebrates demonstrates the power and potential of our
approach.
 I hypothesize that fixed mutations between these species control spatiotemporal expression of
both known and novel craniofacial genes underlying the highly divergent craniofacial features observed
in pupfishes. I propose to investigate the genetic basis of novel adaptive phenotypes in this non-model system
using a combination of population genomics, de novo genome assemblies, phenomics, quantitative genetics,
transcriptomics, in situ hybridization, gene overexpression and chemical inhibition, and CRISPR-Cas9 genome
editing. By integrating candidate gene and variant discovery with functional genetics in a natural system
exhibiting diverse craniofacial features the proposed research will demonstrate the feasibility and power of new
non-model systems to gain novel insights into the developmental genetics of human diseases.

## Key facts

- **NIH application ID:** 10883481
- **Project number:** 2R01DE027052-07A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA BERKELEY
- **Principal Investigator:** Christopher Herbert Martin
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $428,985
- **Award type:** 2
- **Project period:** 2018-08-01 → 2029-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10883481

## Citation

> US National Institutes of Health, RePORTER application 10883481, Discovery and functional analysis of novel candidate genes and variants underlying craniofacial diversification in Cyprinodon pupfishes (2R01DE027052-07A1). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10883481. Licensed CC0.

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