Doris Wagner, PhD

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Contact information
103G Lynch Building
415 University Ave
Philadelphia, PA 19104
Office: 215 898-0483
Fax: 215 898-8780
Education:
Vordiplom (Plant Biology)
Universität München, Weihenstephan, 1988.
PhD (Plant Biology)
University of California at Berkeley, 1995.
Postdoc (Plant Development)
Caltech, 2000.
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Description of Research Expertise

Research Interests
Molecular mechanisms controlling developmental transitions in response to environmental and endogenous cues.

Key words: Transcriptional Regulation, Development, Chromatin Remodeling

Description of Research
My lab is interested in understanding how the accessibility of genomes compacted into chromatin is altered in response to developmental or environmental signals. We study one of the two known mechanisms that can alter access to the genetic information in the context of chromatin, ATP-dependent chromatin remodeling. A second focus of the lab is elucidation of the molecular mechanisms that underlie the vital transition to reproductive development in the plant model system Arabidopsis thaliana. Specifically, we investigate how the master transcription regulator LEAFY (LFY) direct primordium formation and program the primordium founder cells to adopt a floral fate during the onset of reproduction.

Role of chromatin remodeling in development
My lab studies the role of chromatin remodeling in multicellular eukaryote growth, response to stress and development. We use Arabidopsis thaliana as a model system. Plants are an ideal system for studying chromatin mechanisms, as sessile organisms they have evolved adaptive mechanisms for altering cell function and even their body plan in response to different environments. In addition, in contrast to metazoan SWI/SNF ATPases, single null mutations in plant SWI/SNF ATPases cause severe development and growth aberrations, but are not embryonic lethal; facilitating their genetic investigation. Our combined genetic, molecular and genomic studies have revealed that these chromatin remodeling ATPases regulate many distinct processes. In each process they control expression of one or very few key regulators. This surprising functional specificity is in contrast to their previous classification as ‘general’ transcriptional co-regulators. Our current research aims to elucidate how this specificity is achieved.

Developmental reprogramming by the LEAFY transcription factor
LEAFY (LFY) is a helix-turn-helix transcription factor and master regulator that controls the onset of reproduction. Using both global expression and binding studies, we have identified the direct LFY targets at two developmental stages. LFY has stage-specific roles that are in part mediated by interactions with chromatin regulators. We are now studying the roles of the LFY targets in the transition to reproductive development.

Techniques employed
Molecular biology; (Epi)Genomics; Developmental biology; Genetics; Biochemistry

Rotation Projects for 2009-2010
1. Genetic and genomic investigation of the role of chromatin remodeling in pluripotency and differentiation
2. Recruitment of chromatin complexes to target genes
3. Function of LEAFY targets in the reproductive transition
4. Induction of LEAFY mRNA expression and regulation of LFY activity
5. Organogenesis in plants


Lab personnel:
Dr. Kostas Vlachonasios; sabbatical visitor
Dr. Miin-Feng Wu; postdoc
Dr. Nobutoshi Yamaguchi; postdoc
Soon-Ki Han; graduate student
Gleb Bazilevsky; rotation student

Selected Publications

Vercruyssen, L. Verkest, A. Gonzalez, N. Heyndrickx, K. S. Eeckhout, D. Han, S. K. Jegu, T. Archacki, R. Van Leene, J. Andriankaja, M. De Bodt, S. Abeel, T. Coppens, F. Dhondt, S. De Milde, L. Vermeersch, M. Maleux, K. Gevaert, K. Jerzmanowski, A. Benhamed, M. Wagner, D. Vandepoele, K. De Jaeger, G. Inze, D.: ANGUSTIFOLIA3 Binds to SWI/SNF Chromatin Remodeling Complexes to Regulate Transcription during Arabidopsis Leaf Development. The Plant Cell 26(1): 210-29, 2014.

Efroni, I., Han, S. K., Kim, H. J., Wu, M. F., Steiner, E., Birnbaum, K. D., Hong, J. C., Eshed, Y., Wagner, D.: Regulation of leaf maturation by chromatin-mediated modulation of cytokinin responses. Dev Cell 24(4): 438-45, 2013.

Yamaguchi, N., Wu, M. F., Winter, C. M., Berns, M. C., Nole-Wilson, S., Yamaguchi, A., Coupland, G., Krizek, B. A., Wagner, D.: A molecular framework for auxin-mediated initiation of flower primordia. Dev Cell 24(3): 271-82, 2013.

Han, S. K., Wagner, D.: Role of chromatin in water stress responses in plants. Journal of experimental botany 2013.

Han, S. K., Sang, Y., Rodrigues, A., Wu, M. F., Rodriguez, P. L., Wagner, D.: The SWI2/SNF2 chromatin remodeling ATPase BRAHMA represses abscisic acid responses in the absence of the stress stimulus in Arabidopsis. The Plant Cell 24(12): 4892-906, 2012.

Yamaguchi, N., Yamaguchi, A., Abe, M., Wagner, D., Komeda, Y.: LEAFY controls Arabidopsis pedicel length and orientation by affecting adaxial-abaxial cell fate. The Plant journal. 69(5): 844-56, 2012.

Wu, M. F., Wagner, D.: RNA in situ hybridization in Arabidopsis. Methods in molecular biology 883: 75-86, 2012.

Wu, M. F., Sang, Y., Bezhani, S., Yamaguchi, N., Han, S. K., Li, Z., Su, Y., Slewinski, T. L., Wagner, D.: SWI2/SNF2 chromatin remodeling ATPases overcome polycomb repression and control floral organ identity with the LEAFY and SEPALLATA3 transcription factors. Proceedings of the National Academy of Sciences of the United States of America 109(9): 3576-81, 2012.

Sang, Y., Silva-Ortega, C. O., Wu, S., Yamaguchi, N., Wu, M. F., Pfluger, J., Gillmor, C. S., Gallagher, K. L., Wagner, D.: Mutations in two non-canonical Arabidopsis SWI2/SNF2 chromatin remodeling ATPases cause embryogenesis and stem cell maintenance defects. The Plant journal 2012.

Pastore, J. J., Limpuangthip, A., Yamaguchi, N., Wu, M. F., Sang, Y., Han, S. K., Malaspina, L., Chavdaroff, N., Yamaguchi, A., Wagner, D.: LATE MERISTEM IDENTITY2 acts together with LEAFY to activate APETALA1. Development 138(15): 3189-98, 2011.

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Last updated: 03/18/2014
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