Stephen L Dellaporta
Professor of Molecular, Cellular, and Developmental Biology
Research Interests
Functional genomics; plant molecular genetics; marine genomics; biofuels
Current Projects
HarvestPlus, a collaborative project to biofortify maize for developing countriesNSF, Evolutionary genetics of allorecognition in a marine hydroid
NIH, Molecular basis for allorecognition
Various, Sex determination in maize
Research Summary
My lab is interested in the study the pathway of
sex determination in maize, a process that involves cell death and
cell arrest. Zea
mays is an ideal organism for molecular genetic studies on the sex
determination
process. Maize produces unisexual flowers, called florets in grasses,
with
pistillate (female) florets formed in the ear and staminate (male)
florets
formed in the tassel. Initially, these floral meristems are bisexual
(cosexual).
Through the action of sex determination (SD) genes they later become
unisexual
by the selective elimination of one sex and maturation of preformed
organ
primordia of the opposite sex. The formation of staminate florets in
the
tassel involves programmed death of pistil subepidermal cells and
sexual
maturation of stamen initials. Our mission is to understand these
pathways
in maize, including the associated processes of tasselseed-mediated
pistil cell death, silkless-mediated pistil cell protection,
and
gibberellin (GA)-mediated stamen cell arrest.
We are also interested in unraveling the origin and early diversification
of Antp superclass homeobox genes (including Hox genes and the related
ParaHox and NK-like genes) in Trichoplax adhaerens. Trichoplax is
a simple diploblastic metazoan with the smallest known animal genome, only
ten times that of the bacterium E. coli. Our project includes testing
the hypothesis that physical clustering of homeobox genes is a unique character
of animal genomes, exploited repeatedly during animal evolution. In pursuing
this goal, we are developing Trichoplax adhaerens as a new model
system for primitive animal studies along with comparative genetic data from
sponges, cnidarians, and choanoflagellates.
Selected Publications
- Acosta, I.F., Laparra, H., Romero, S.P., Schmelz, E., Hamberg, M., Mottinger, J.P., Moreno, M.A., and Dellaporta, S.L. (2009). tasselseed1 is a lipoxygenase affecting jasmonic acid signaling in sex determination of maize. Science (New York, NY 323, 262-265.
- Nicotra, M.L., Powell, A.E., Rosengarten, R.D., Moreno, M., Grimwood, J., Lakkis, F.G., Dellaporta, S.L., and Buss, L.W. (2009). A hypervariable invertebrate allodeterminant. Curr Biol 19, 583-589.
- Schierwater, B., Eitel, M., Jakob, W., Osigus, H.J., Hadrys, H., Dellaporta, S.L., Kolokotronis, S.O., and Desalle, R. (2009). Concatenated analysis sheds light on early metazoan evolution and fuels a modern "urmetazoon" hypothesis. PLoS biology 7, e20.
- Srivastava, M., Begovic, E., Chapman, J., Putnam, N.H., Hellsten, U., Kawashima, T., Kuo, A., Mitros, T., Salamov, A., Carpenter, M.L., et al. (2008). The Trichoplax genome and the nature of placozoans. Nature 454, 955-960.
- Poudyal, M., et al. (2007). Embryonic chimerism does not induce tolerance in an invertebrate model organism. Proc. Natl. Acad. Sci. (USA) 104:4559-4564.
- Kamm, K., Schierwater, B., Jakob, W., Dellaporta, S.L., and Miller, D.J. (2006). Axial patterning and diversification in the cnidaria predate the Hox system. Curr. Biol. 16:920-926.
