Molecular Evolution of Embryogenesis in Nematodes: A Comparison between R. culicivorax and C. elegans

• Applicant: Dr. Jens Schulze
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology)
• Term: Funded in 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 214901511

Nematodes can be subdivided into basal Enoplea (Clade 1-2) and more derived Chromadorea (Clade 3-12). Intensive studies reveal that the taxon shows unexpectedly high differences concerning establishment of polarity and axes, cell determination, embryonic patterning, cell lineage and organogenesis. Hence, embryogenesis of the model organism C. elegans (Clade 9) is typical only for a subgroup of the Chromadorea. Therefore, a better understanding of evolution of developmental processes among nematodes requires the study of additional representatives. Based on my preliminary work on embryogenesis of the basal nematode R. culicivorax (Clade 2) this species appears to be a suitable candidate for further studies, since it combines plesiomorpic embryonic characters of the Enoplea with some apomorphic characters of the Chromadorea. Making use of its recently sequenced genome (our unpublished data) in combination with established molecular methods for the visualization of gene expression patterns should allow me to unravel peculiarities of its embryogenesis and to draw conclusions concerning the evolution of nematode development. In particular I would like to clarify the role of polarly organized interphase microtuble caps for putative asymmetric distribution of mRNA and cell specification. Furthermore I want to understand the function of the underlying gene machinery necessary for the establishment of polarity, axes and asymmetry in embryogenesis of basal nematodes and point out evolutionary changes compared to C. elegans. Finally, I want to study HOX genes to determine whether these are expressed in a lineage-dependent manner (like in C. elegans) or in a position dependent manner (like in Drosophila and many other organisms). This may help to determine whether the alignment of founder cells with different fate along the anterior-posterior axis can be interpreted as remnants of an originally existent segmentation that was lost during evolution.

• DFG Programme: Research Fellowships
• International Connection: USA
• Hosts: Professor Dr. Paul de Ley; Professor Dr. Morris Maduro; Professor Dr. Edward Platzer