[
International Worm Meeting,
2011]
Development and ageing are strongly interlinked with metabolism. Especially in C.elegans this relationships becomes apparent with the insulin like signalling pathway (IIS), mitochondrial activity and dietary restriction having a direct effect on lifespan. We recently showed (Fuchs et. al. 2010) that untargeted metabolic profiling (metabolomics | metabonomics) can be used to find a signature of long-life by comparing different longevity mutants and old worms.
By optimising tissue extraction protocols and incorporating chromatography mass spectrometry coupled approaches (GC-MS, LC-MS) we have refined our methodology to achieve a higher coverage of C.elegans metabolites (pathways) and increased sensitivity, aiming at single worm concentrations. We also use stable isotopes (13C, 15N) to label the C.elegans metabolome to help identify (novel) metabolites to increase coverage and trace the fate of dietary uptake.
By providing this array of new tools to the C.elegans (metabolomics) community, we hope to help improve the understanding of metabolism in this important model organism.
[
International Worm Meeting,
2011]
Nematodes are well suited for a comparative study of early embryogenesis. Analyzing development of a single model system like Caenorhabditis elegans does not shed any light on the degree of evolutionary modifications within the taxon Nematoda. For better understanding evolution of development among nematodes including the identification of plesiomorphic and apomorphic characters, we compared early embryogenesis of representatives from all 12 nematode clades (phylogeny after Holterman et al., 2006; Mol. Biol. Evol. 23:1792-1800). Our data reveal that embryogenesis is unexpectedly variable with floating transitions that can be interpreted as frozen images of evolutionary change. Particularly, members of clade 1 and 2 differ massively from the standard C. elegans. Nevertheless, some basic developmental similarities appear to be common among all nematodes, e.g. the general existence of at least partial cell lineages and the influence of Polarity Organizing Centers (POCs). These POCs are required for generating a linear sequence of cells along the a-p axis which constitute the ventral midline. Depending on phylogenetic position fewer or more cells of this midline divide into left and right daughters this way establishing bilateral symmetry within individual lineages. Our studies reveal the stepwise emergence of founder cells and dramatic fate shifts during evolution. The comparison between embryogenesis of the basal nematode Tobrilus stefanskii and the tardigrade Hypsibius dujardini (Gabriel et al., 2007; Dev. Biol. 312, 545-59) with respect to the early cell division pattern revealed surprising similarities between these two. This may be considered as embryological support for the Ecdysozoa hypothesis.