# Using naturally evolved phenotypic variation to decipher the positional regulatory code of mammalian skin

> **NIH NIH R35** · PRINCETON UNIVERSITY · 2021 · $396,930

## Abstract

Project summary
My proposed research seeks to uncover the precise developmental mechanisms by which gene
regulatory complexity is translated through cellular behaviors into specific morphological
outcomes. Achieving this constitutes a fundamental challenge in biomedical sciences, as errors
in embryonic patterning often lead to congenital and postnatal abnormalities that can have
The mammalian skin displays marked anatomical variation
in growth, thickness, pigmentation, and types of cutaneous appendages. These regional
differences arise during embryogenesis, suggesting that gene regulatory networks controlling
skin development harbor a latent reservoir of anatomical complexity. To understand how such
regulatory complexity is translated into spatial patterns of cellular differentiation,
drastic consequences for individuals.
my research
program combines the study of diverse, naturally occurring phenotypes in emerging model
species, with parallel studies in the laboratory mouse, where powerful molecular and genetic
tools already exist. The proposed experiments seek to elucidate how the skin acquires,
interprets, and executes positional information by focusing on two distinct spatially patterned
phenomena during skin development (1) stripe pattern formation in rodents, using a system I
established as a postdoc and (2) formation of gliding membranes in marsupials, using a system
under development in my laboratory. The approaches described in the two research programs
integrate multiple disciplines, including developmental biology, molecular biology, evolutionary
genetics, and functional genomics, with my expertise in skin developmental biology
(postdoctoral training) and demonstrated success developing molecular tools in emerging model
species (graduate and postdoctoral training). By focusing on developmental mechanisms, this
work will uncover the stepwise processes by which genetic information generates spatial
patterns of cellular differentiation during embryogenesis, provide a comprehensive roadmap for
linking genotype and phenotype at an unprecedented mechanistic and conceptual level, and will
generate fundamental insights into the biology of mammalian skin, from the processes
controlling skin development and homeostasis to the mechanistic bases of diseased states.

## Key facts

- **NIH application ID:** 10246985
- **Project number:** 5R35GM133758-03
- **Recipient organization:** PRINCETON UNIVERSITY
- **Principal Investigator:** Ricardo Mallarino
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $396,930
- **Award type:** 5
- **Project period:** 2019-09-13 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10246985

## Citation

> US National Institutes of Health, RePORTER application 10246985, Using naturally evolved phenotypic variation to decipher the positional regulatory code of mammalian skin (5R35GM133758-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10246985. Licensed CC0.

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