Kewalo Marine Laboratory University of Hawaii 41 Ahui Street Honolulu HI 96813 mqmartin@hawaii.edu http://www.kewalo.hawaii.edu/research_faculty.htm##mark
[publications] [graduate students]We are interested in a broad range of problems associated with the cellular, molecular, and evolutionary basis of biological pattern formation. We are particularly interested in events leading to changes in metazoan body plans. My lab utilizes a variety of cellular and molecular techniques (e.g., PCR, cloning, sequencing, whole-mount in situ hybridization, immunolocalization) in conjunction with classical techniques of microinjection, cell labeling, cell ablation, and transplantation, to address fundamental problems in developmental biology in a phylogenetic context.
My lab is currently focused in three major areas. The first is to understand the cellular and molecular formation of metameric body plans. We work primarily on glossiphoniid leech and polychaete annelid embryos due to their stereotyped mode of embryogenesis and relatively simple body plan. We are currently looking at the role of the early cleavage program and known transcription factors, such as homeodomain-containing family members, in the establishment of both global symmetry properties, (e.g., body segment identity, formation of lateral appendages) and the specification of individual cell types (e.g., identified neurons). We are hoping to extend these studies into other phyla of protostome "worms" such as the sipunculids and echiurans which share a common pattern of early development with annelids, but do not show over signs of segmentation during adulthood.
The second area of interest is to understand the relationship between radially symmetrical and bilaterally symmetrical organisms. 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 patterning events conserved in this group of animals? We are investigating these and other aspects of early development in both cnidarian and ctenophore embryos.
The third 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 flatworms). Of particular interest is the mechanisms by which dorsoventral polarity is established and the precise origins of mesodermal tissue in members of different lophotrochozoan phyla. We are also interested in understanding the 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 (direct development).
Finnerty JR, Martindale MQ.1999. Ancient origins of axial patterning genes: Hox genes and ParaHox genes in the Cnidaria. Evol Develop 1:16-23.
Martindale MQ, Henry JQ. 1999. Intracelular fate mapping in a basal metazoan, the ctenophore Mnemiopsis leidyi, reveals the origins of mesoderm and the existence of indeterminate cell lineages. Develop Biol, In Press.
Irvine SQ, Martindale MQ. 1999. Expression patterns of anterior
hox genes in the polychaete
Chaetopterus:Correlation with morphological boundaries. Develop
Biol, In Press.
Finnerty JR, Martindale MQ. 1999. The Evolution of the Hox Cluster: Insights from Outgroups. In Doolittle WF, Akam M (editors). Current Opinions in Genetics and Development. Genomes and Evolution. Dec. 1998, 8: 681-687.
Martindale MQ, Kourakis M.J. 1999. Hox clusters: Size doesn't matter. News and Views. Nature 399:730-733
Boyer BC, Henry, JQ, Martindale MQ. 1998. The cell lineage of a polyclad turbellarian embryo reveals close similarity to coelomate spiralians. Develop Biol 204:111-123.
Martindale MQ, Henry JQ. 1997. Reassessing embryogenesis in the Ctenophora: The inductive role of e1 micromeres in organizing ctene row formation in the "mosaic" embryo, Mnemiopsis leidyi. Develop 124:1999-2006.
Panganiban G, Irvine SM, Lowe C, Roehl H, Corley LS, Sherbon B, Grenier JK, Fallon JF, Kimble J, Walker M, Wray GA, Swalla BJ, Martindale MQ, Carroll SB. 1997. The origin and evolution of animal appendages. Proc Natl Acad Sci USA 94:5162-5166.
Kourakis M, Master V, Wedeen C, Nardelli-Haefliger D, Shankland
M, Martindale MQ. 1997. Conserved anterior boundaries of Hox gene
expression in the central nervous system of the leech Helobdella.
Develop
Biol 190:284-300.