Introduction

The fields of developmental genetics and evodevo have provided significant insights into how gene regulatory networks (GRNs) control fate specification, and how those networks vary between species. Yet, we still do not understand how GRNs launch specific cell biological behaviors; nor do we know how changes in cell biology have influenced body-plan divergence. To address these gaps in our knowledge, the overarching goals in the Lyons lab are to: 1) make explicit connections between cellular behaviors and GRNs, and 2) use these data to explain how developmental processes evolve, particularly at the cellular level.  We work primarily with echinoderms and molluscs because these groups have unique advantages for studying the evolution of development and cell biology.  

Echinoderms

The phylum Echinodermata includes 5 extant classes: Crinoidea (feather stars and sea lillies), Ophiuroidea (brittle stars and basket stars), Holothuroidea (sea cucumbers), Asteroidea (sea stars), and Echinoidea (sea urchins and sand dollars). These animals have been used for a wide range of studies at all levels of biological organization, from genetics and cell biology on the micro scale, to ecosystem and climate studies on the macro scale.  Our lab is working with sea urchins, sand dollars, and sea stars to understand how cell types become different from one another during development and how these processes differ between species.  Currently we are focusing on local west coast species, the bat star Patiria miniata, and the painted sea urchin Lytechinus pictus, which are easy to work with and are beautiful for imaging. 

Spiralians

Spiralian lophotrochozoans are a diverse assemblage of animals such as snails, clams, polychaetes, earthworms, ribbon worms, and polyclad flatworms. Despite looking different as adults and larvae, these animals share a highly stereotyped suite of characters during early development, called spiral cleavage. From this stereotyped cleavage pattern, clade-specific body-plans emerge, providing a unique opportunity to study how cell fate specification and morphogenesis evolve. Nowhere else in the animal kingdom can different phyla be compared systematically at a single cell level.  We work with gastropod snails and nudibranchs that are amenable to functional studies, to answer fundamental question about molluscan biology, including early patterning, gastrulation, biomineralization, and neurogenesis.