Dr. Smith's research interests include the evolution of stem-cell systems in lower metazoans and the systematics, ecology, and evolutionary relationships of marine meiofaunal flatworms.  His stem-cell work, supported by SC-INBRE, took him to the University of Innsbruck in spring 2011 to learn a suite of molecular techniques applicable to his and his students' research, and to develop a collaboration with Dr. Peter Ladurner's laboratory. Over the past three years, in collaboration with colleagues at two other universities, he has begun examining the effects of beachfront development and other anthropogenic changes on the meiofauna (microscopic animals living between sand grains) at four beaches in North Carolina.

SC-INBRE Research

Control of epidermal mitosis in Aeosoma hedleyi--Is Hegehog (Hh) signaling involved?

A. hedleyi is a small, easily cultured freshwater annelid that reproduces profically in culture by asexual fission. We have established stem-cell labeling (M-phase and S-phase) techniques for this animal (Sara Merlie, Winthrop Undergraduate) and have recently shown that there is a pronounced diurnal variation in mitosis in this organism (Emily Bowie, Winthrop Undergraduate). This latter result is important because we plan next to examine the effects of known small-molecule inhibitors of Hh signaling on mitotic activity in the epidermis of this organism. If an effect is observed, we plan next to develop a transcriptome for A. hedleyi in order to recover the orthologuesof the Hh pathway in this organism.

Functions of Hh signaling in a basal metazoan

Isodiametra pulchra is a small, easily cultured marine acoelomorph with a life cycle of around 26 days. Dr. Peter Ladurner has developed a suite of molecular techniques for the study of developmental regulatory pathways in this organism, concentrating on pathways that regulate gonadal development. This past spring, Dr. Smith spent a semester in Innsbruck to begin elucidating the regulatory role(s) of the Hedgehog pathway in I. pulcha, research that will be continued by Emily Bowie in Dr. Smith's lab this summer.

Epidermal stem cells in lower metazoans

Our work with marine meiofauna provides a number of opportunities to examine the source of new epidermal cells in a variety of vermiform invertebrates. So far, the results point to the possible conclusion that basally-located, dedicated epidermal stem-cell populations are secondarily evolved in the metazoa. Student projects so far include a study of S- and M-phase cells in Ototyphlonemertes (Cedric Williams, Limestone College Undergraduate and Winthrop McNair Scholar), in Lehardyia alleithros (Ashley Whitson, SC-GSSM senior), in a new species of Otoplanid turbellarian (Joseph Bursey, Winthrop Undergraduate), in Stenostomum virginianum (Dan Stanton, Winthrop Undergraduate), in Catenula lemnae (Kevin Ryan, Winthrop Undergraduate) and in Aeolosoma hedleyi (Sara Merlie, Winthrop Undergraduate).