Professor, Department of Biology
Ph.D. Brandeis University
B.S. Utah State
Research Interests: Specification and patterning of the vertebrate nervous system with a focus on developmental interactions between the nervous system, immune system, and host-associated microbiota
Overview: The vertebrate nervous system is composed of a large number of neurons with diverse characteristics that ultimately form the circuits that underlie an animal’s behavioral repertoire. We are interested in several aspects of this process including: 1) How neuronal diversity is generated during development: how are the correct number of cells specified for specific neural and glia fates at particular times and in particular locations? 2) How neuronal circuits are wired up: how do neurons make appropriate connections with their synaptic partners. 3) What are the roles of host-associated microbiota and the immune system during neural development: how do microbes associated with the host interact with the immune system and with the nervous system to shape neuronal architecture, circuitry, and function? We use an approach that combines cellular, molecular, genetic, and microbiological manipulations with live imaging in zebrafish to investigate these questions with the goal of understanding the mechanisms underlying neural development.
Evolution of Endothelin signaling and diversification of adult pigment pattern in Danio fishes.
PLoS Genet. 2018 Sep 18;14(9):e1007538
Authors: Spiewak JE, Bain EJ, Liu J, Kou K, Sturiale SL, Patterson LB, Diba P, Eisen JS, Braasch I, Ganz J, Parichy DM
Fishes of the genus Danio exhibit diverse pigment patterns that serve as useful models for understanding the genes and cell behaviors underlying the evolution of adult form. Among these species, zebrafish D. rerio exhibit several dark stripes of melanophores with sparse iridophores that alternate with light interstripes of dense iridophores and xanthophores. By contrast, the closely related species D. nigrofasciatus has an attenuated pattern with fewer melanophores, stripes and interstripes. Here we demonstrate species differences in iridophore development that presage the fully formed patterns. Using genetic and transgenic approaches we identify the secreted peptide Endothelin-3 (Edn3)-a known melanogenic factor of tetrapods-as contributing to reduced iridophore proliferation and fewer stripes and interstripes in D. nigrofasciatus. We further show the locus encoding this factor is expressed at lower levels in D. nigrofasciatus owing to cis-regulatory differences between species. Finally, we show that functions of two paralogous loci encoding Edn3 have been partitioned between skin and non-skin iridophores. Our findings reveal genetic and cellular mechanisms contributing to pattern differences between these species and suggest a model for evolutionary changes in Edn3 requirements for pigment patterning and its diversification across vertebrates.
PMID: 30226839 [PubMed - as supplied by publisher]