# VERTEBRATE PIGMENT CELLS AND PATTERN FORMATION

> **NIH NIH R01** · UNIVERSITY OF KANSAS LAWRENCE · 1989 · $94,281

## Abstract

The general aim of the proposed research is to examine how certain
"exogenous" and "endogenous" factors regulate the expression of animal
pigments and pigment cells.  The approach taken will involve administering
allopurinol (a drug used to treat gout in humans) to experimental animals
(in this case, axolotls--salamanders) and observing changes that occur in
the pigment phenotype.  The primary action of allopurinol is to inhibit the
enzyme, xanthine dehydrogenase (XDH).

It is known from preliminary studies that allopurinol administration to
wild type axolotls for periods of from 2-8 weeks results in a gradual
darkening of the overall pigment phenotype.  During this time, changes
occur in the outward appearance of drug-treated animals that apparently
involve increasing one pigment cell type (melanophores) accompanied by
gradual decreases and eventual disappearance of the other pigment cell
types (xanthophores and iridophores).  Because the phenotypic changes
elicited by allopurinol treatment are identical to the phenotypic
characteristics of a genetic mutation in axolotls known as melanoid, it is
suspected that these two phenomena are related.  Thus, four experimental
objectives that are designed to investigate how XDH activity and "melanism"
might be related are proposed:  (1) structural studies to follow the fate
of the three pigment cell types during drug treatment, (2) quantitative
and/or qualitative analyses of purine, pteridine and melanin pigments
during drug treatment, (3) analysis of XDH activity during the development
of wild type and melanoid axolotls and in drug-treated animals, and (4)
administration of allopurinol, purines and pteridines to melanoid axolotls
followed by observations of any change in phenotype.  Objectives 1-3 are
directed toward understanding how XDH activity affects pigment synthesis
and, ultimately, pigment cell differentiation.  Objective 4 involves a set
of preliminary experiments designed to alter and/or correct the melanoid
defect.

## Key facts

- **NIH application ID:** 3156853
- **Project number:** 5R01AR034478-06
- **Recipient organization:** UNIVERSITY OF KANSAS LAWRENCE
- **SAM.gov UEI:** SSUJB3GSH8A5
- **Principal Investigator:** SALLY K FROST
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $94,281
- **Award type:** 5
- **Project period:** 1984-07-01 → 1990-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3156853

## Citation

> US National Institutes of Health, RePORTER application 3156853, VERTEBRATE PIGMENT CELLS AND PATTERN FORMATION (5R01AR034478-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3156853. Licensed CC0.

---

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