Experimental Embryology and Evo-Devo
Addressing fundamental problems in biological pattern formation
We are interested in a broad range of problems associated with the cellular, molecular, and evolutionary basis of biological pattern formation. My lab utilizes a variety of molecular and "classical" techniques of microinjection, cell labeling, ablation, and transplantation, to address fundamental problems in developmental biology in a broad phylogenetic context.
My lab is currently focused in three major areas. The first area of interest is to understand the role of the early cleavage program in the segregation of developmental potential in a wide variety of animals which share a mode of embryogenesis known as spiral cleavage (e.g., molluscs, annelids, nemerteans, sipunculids, echiurans, and polyclad flatworms). Of particular interest is the mechanism by which dorsoventral polarity is established in members of different spiralian phyla. We are also interested in understanding the origins and significance of naturally evolved variations in the spiral cleavage program, such as modifications associated with the abandonment of larval development in order to develop directly to a miniature adult form (i.e., direct development). We consistently use intracellular cell lineage labeling and cell ablation techniques in a wide variety of species for many of our experiments.
The second area of interest is gaining an understanding of the relationship between radially symmetrical and bilaterally symmetrical metazoans. Current theory predicts that bilaterians are derived from a radially symmetrical stock, yet there is little evidence for how such a transition might have occurred. For example, what is the relationship of the oral-aboral axis of radially symmetrical forms to the anterior-posterior of bilaterians? How did the dorsoventral axis arise? Is there evidence for the origins of major cleavage patterns in bilaterian development (e.g., spiral and radial cleavage) in radially symmetrical forms? To what degree are the molecular events underlying morphological patterning and cell type specification conserved in this group of animals? We are investigating these and other aspects of early development in representatives of both anthozoan cnidarian and ctenophore embryos.
The third area of focus is to understand the evolution of biological novelties. These include the origins of the "middle" germ layer (mesoderm), the evolution of the nervous system in the Metazoa, and the evolution of unique cell types (cnidocytes, colloblasts, sensory cells, etc.). Many of these studies utilize cnidarians (the starlet sea anemone Nematostella vectensis) and ctenophores (the lobate Mnemiopsis leidyi), both of whose genomes have been sequenced. We continue to developed functional techniques to uncover conserved and novel molecular mechanisms underlying novel cell type formation.
Mark Q. Martindale, Ph.D.
Director of the Whitney Laboratory, Professor of Biology
Dr. Martindale obtained a B.A. in natural sciences at New College of Florida and earned his Ph.D. in zoology at the University of Texas.
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