CEPCEB Members
Morris Maduro
Assistant Professor of Biology
3380 Spieth Hall
Biology Department
University of California, Riverside
Riverside, CA 92521
Phone: (951) 827-7196
http://www.faculty.ucr.edu/~mmaduro
| Areas of Expertise |
- Developmental Biology
- Gene Regulatory Networks
- Evolution of Gene Specification Pathways
- Mechanisms of Gene Regulation
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Background
I received my Bachelor of Science degree in Mathematics from the University of Alberta, Canada. I also received my PhD in Biology (Genetics) from the same institution. For my doctoral work, I studied the development of the nervous system of the nematode, C. elegans. I became fascinated by the emerging set of tools that allowed molecular biologists to probe many biological questions in this animal. For my postdoctoral work, I studied the genetic mechanisms that specify early C. elegans embryonic cells. In 2003, I joined the Department of Biology at UC Riverside as an Assistant Professor.
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Embryonic Development in C. elegans
My laboratory has two areas of research using the nematode, C. elegans, as a model system. First, we are interested in how the early cells of the C. elegans embryo acquire their unique properties during development. To this end, we are characterizing the gene regulatory network that specifies the 8-cell stage precursors MS (mesoderm) and E (endoderm). Our second project is a collaboration with the laboratory of Dr. Shou-Wei Ding (UCR Plant Pathology) using C. elegans as an animal system in which to study the antiviral immunity that RNA interference (RNAi) confers.
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| Figure 1: Wild-type C. elegans adult (approximately 1mm long). |
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C. elegans embryos are only 50 microns long. Within 14 hours of fertilization, the juvenile is completely formed. As part of my postdoctoral work, I elucidated a gene regulatory network that specifies the major endomesoderm precursor cell EMS. We are continuing these studies in my laboratory at UCR, with the broad goal of identifying the entire suite of regulators that operates in cell fate specification of the two descendants of EMS, called MS (a mesoderm precursor) and E (the endoderm precursor). The regulators MED-1,2 activate the T-box gene tbx-35 in the MS cell, and contribute to the activation of the GATA factors end-1,3 in the E cell. The MS and E cells are made different from each other by the conserved Wnt pathway, which transduces a signal resulting from interaction of the EMS cell with its neighbor P2. |
| Figure 2: Overview of the specification of MS and E by the activation of tbx-35 and end-1,3 |
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Gene Regulatory Networks in Development and Evolution We can represent these regulatory genes as part of a larger Gene Regulatory Network (GRN). The types of regulatory connections (i.e. the architecture) of the genes in the C. elegans endomesoderm GRN are similar to those found in GRNs characterized in other systems, from yeast to mammals. We are now examining the closely related nematode species C. briggsae and C. remanei to better understand how evolutionary flexibility is built into this network.
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| Figure 3: C. elegans endomesoderm GRN |
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RNA Interference as an Antiviral Mechanism in C. elegans
We also have an ongoing collaboration with the laboratory of Dr. Shou-Wei Ding at UCR on the replication of the Flock House Virus in C. elegans. This (+)-strand virus expresses a protein, B2, that suppresses the host response to invading RNA genomes. With the extensive characterization of RNAi mechanisms in C. elegans, we are developing resources to study the role of RNAi components in the antiviral process.
Lab Personnel and Projects
- Gina Broitman-Maduro, Research Associate: Control of expression of genes in the early C. elegans embryo
- Tan-Hui (Katy) Lin, PhD candidate (CMDB): Analysis of cis-regulatory sites mediating lineage-specific expression in the early C. elegans embryo
- Wendy Hung, PhD candidate (CMDB): protein-DNA interactions involving the divergent MED-type GATA factors and T-box genes
- Samer Elkashef, collaborating PhD student (GGB, Ding lab): chemical genomics and RNAi pathways in antiviral immunity
Selected Publications (Bibliography page)
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