Research Summary

Two questions motivate my work: How does an animal develop from a single, fertilized oocyte to a multicellular adult organism? And how did over a million animal species evolve from a single metazoan ancestor? The first question about development can stand alone and can be pursued by studying a single organism. The second question about evolution cannot stand alone but depends on the study of diverse organisms. During my scientific career, I have worked for the most part on the development of crustaceans. The development of crustaceans is interesting in itself, but most of my studies of crustacean development were explicitly tailored to bridge from the knowledge on Drosophila development to the classical questions about animal phylogeny and to the emerging ideas about the evolution of development.

One project is the early cell lineage of Parhyale, an amphipod crustacean. Parhyale shows a total early cleavage that is invariant and sets up four macromeres and four micromeres at the 8-cell stage. I established an injection technique for this species and analyzed macromere and micromere cell lineages: three macromeres are ectoderm progenitors and the fourth generates visceral mesoderm; two micromeres are somatic mesoderm progenitors, the third micromere is a progenitor for germ cells and the fourth macromere generates the endoderm. This is the first report of an arthropod cell lineage from cleavage to organogenesis and it has three major implications: First, the specification of progenitors for the germ layers at the 8-cell stage is earlier than those documented for any other metazoa. Second, the total cleavage and the invariant cell lineage of Parhyale are novel features of the amphipods since all close relatives of the amphipods show superficial cleavage and no cell lineage. Third, the cell lineage of Parhyale bears some similarity to cell lineages that were reported previously for several crustacean taxa unrelated to Parhyale (Gerberding et al. 2002).

In another project, I investigate the segmentation of Parhyale. Segmentation in Parhyale is tied to cell lineage. During germ band formation, a rectangular grid of primary rows and columns is set up in the ectoderm. Previous studies showed that the primary rows divide twice, generating rows a-d. Row a turns on the homolog of the Drosophila segment-polarity gene engrailed. To understand the patterning prior to the engrailed expression, I cloned the homolog of the Drosophila pair-rule gene runt. In Parhyale, runt is expressed prior to row formation. I am currently analyzing the expression pattern and doing experiments on an RNAi knockdown (Gerberding and Patel, in prep.).

Publications

• Gerberding, M., Browne, W. E., and Patel, N.H. (2002) Cell lineage analysis of the amphipod crustacean, Parhyale hawaiensis, reveals an early restriction of cell fates. Development 129: 5789-58011

• Gerberding, M., and Scholtz, G. (2001) Neurons and glia in the midline of the higher crustacean Orchestia cavimana are generated via an invariable cell lineage that comprises a median neuroblast and glial progenitors. Developmental Biology 235: 397-409

• Gerberding, M., and Scholtz, G. (1999) Cell lineage of the midline cells in the amphipod crustacean Orchestia cavimana (Crustacea, Malacostraca) during formation and separation of the germ band. Development Genes and Evolution 209: 91-102

• Scholtz, G., Mittmann, B., and Gerberding, M. (1998) The pattern of Distal-less expression in the mouthparts of crustaceans, myriapods, and insects: new evidence for a gnathobasic mandible and the common origin of Mandibulata. International Journal of Developmental Biology 42: 801-810

• Gerberding, M. (1997) Germ band formation and early neurogenesis in Leptodora kindti (Cladocera): first evidence for neuroblasts in entomostracan crustaceans. Invertebrate Reproduction and Development 32: 63-73

Presentations:

• Gordon Conference Developmental Biology, New Hampshire, USA (2003)
• Drosophila Annual Research Conference, Chicago, USA (2003)
• Central Michigan University, Mt. Pleasant, USA (2003)
• Society of Developmental Biology Annual Meeting, Madison, USA (2002)
• Cold Spring Harbor Meeting on Evolution of Developmental Diversity, USA (2002)
• Hokkaido University, Sapporo, Japan (2001)
• Wayne State University, Detroit, USA (2000)

Education

• Postdoctoral Fellow
Nipam Patel, University of Chicago and UC Berkeley
(June 1999-March 2003)

• Dr. rer. nat. in Biology
Humboldt-Universität Berlin:
1994-1999

• Diploma in Biology
Freie Universität Berlin
1988-1994

Fellowships:

• Federal State Berlin, Graduate Fellowship Program, Fellow (1995-1997)
• DFG Graduiertenkolleg , Associate Fellow (1995-1997)
• Studienstiftung des Deutschen Volkes (German National Merit Foundation), Fellow (1991-1994)