Ph.D. University of California, Los Angeles
Office/Building: Biol 334
Our lab studies the molecular genetics of seed development. Our current focus is on development of the endosperm. Endosperm is an important component of the seed because it provides nutrients and developmental signals to the embryo during seed development. Furthermore, endosperm is an important source of food, feed, and industrial raw materials. Approximately two-thirds of human calories are derived from endosperm. Our goal is to understand the molecular processes controlling endosperm development. We are taking three complementary approaches: forward genetics, reverse genetics, and genomics. For these studies, we are using the model genetic organism Arabidopsis thaliana. In forward-genetics screens, we identified several Type I MADS domain transcription factors important for endosperm development. Two of these are AGL80 and AGL62. AGL80 is expressed in the central cell and regulates the expression of genes necessary for central cell and early endosperm development (Portereiko et al., 2006). AGL62 regulates cellularization during early endosperm development (Kang et al., 2008). A current focus in the lab is analysis of additional Type I MADS box genes regulating endosperm development. Using genomics approaches, we identified a large collection of genes expressed in the central cell and endosperm (Steffen et al., 2007). Many of the identified genes encode transcription factors and we currently are using the reverse-genetics resources available for Arabidopsis to determine the functions of these genes.
- Steffen, J.G., Kang, I.-H., Portereiko, M.F., Lloyd, A., and Drews, G.N. (2008) AGL61 interacts with AGL80 and is required for central cell development in Arabidopsis. Plant Physiology, 148, 259-268.
- Punwani, J.A., Rabiger, D.S., Lloyd, A., and Drews, G.N. (2008) The MYB98 subcircuit of the synergid gene regulatory network includes genes directly and indirectly regulated by MYB98. Plant Journal 55, 406-414.
- Kang, I.-H., Steffen, J.G., Portereiko, M.F., Lloyd, A., and Drews, G.N. (2008) The AGL62 MADS domain protein regulates cellularization during endosperm development in Arabidopsis. Plant Cell 20, 635-647.
- Punwani, J.A., and Drews, G.N. (2008) Development and function of the synergid cell. Sexual Plant Reproduction 21, 7-15.
- Punwani, J.A., Rabiger, D.S., and Drews, G.N. (2007) MYB98 positively regulates a battery of synergid-expressed genes encoding filiform apparatus-localized proteins. Plant Cell 19, 2557-2568.
- Portereiko, M.F., Lloyd, A., Steffen, J.G., Punwani, J.A., Otsuga, D., and Drews, G.N. (2006) AGL80 is required for central cell and endosperm development in Arabidopsis. Plant Cell 18, 1862-1872.
- Steffen, J.G., Kang, I.-H., Macfarlane, J., and Drews, G.N. (2007) Identification of Genes Expressed in the Arabidopsis Female Gametophyte. Plant Journal 51, 281-292.
- Biol 3230: Developmental Biology Lecture
- Biol 3235: Developmental Biology Lab
- Biol 2020: Principles of Cell Biologu