Pigment patterns: fish in stripes and spots

Abstract

The analysis of zebrafish pigment pattern development suggests a model for the genes and cell populations required to make an adult pigment pattern and provides a useful starting point for identifying the mechanisms underlying pigment pattern evolution across species.A recent approach has used interspecific hybrids. When zebrafish are crossed to other danios (Figure 1Figure 1), the resulting pigment patterns typically resemble that of zebrafish more than the other species, suggesting that pigment pattern genes in other species often are recessive to those of zebrafish. This has allowed for interspecific complementation tests to determine whether genes identified as zebrafish pigment pattern mutants might contribute to differences between taxa. For example, hybrids between wild-type zebrafish and D. albolineatus form stripes like zebrafish, whereas hybrids between fms mutant zebrafish and D. albolineatus lack stripes, like D. albolineatus, identifying fms as a candidate gene for stripe elaboration in zebrafish, or stripe loss in D. albolineatus.Danio pigment patterns offer an outstanding opportunity for integrative studies that link genetic and cellular mechanisms to behavior, ecology, and natural selection in the wild. In the future, identification of additional genes and cell behaviors required for pigment pattern formation in zebrafish will provide valuable resources and testable hypotheses for dissecting the evolution of neural crest derivatives in danios and vertebrates more generally.