The evolution of dauer formation

The nematode dauer stage is a specialized larval stage for enduring adverse conditions and for dispersal. In response to environmental cues indicating these situations, nematodes pause their normal development and metamorphose into the dauer state. C. elegans  enters into the dauer state under the conditions of scarce food, high temperature or overcrowding. Molecular mechanisms underlying dauer formation in C. elegans are genetically well characterized, providing the basis for comparative studies in other species.
We are investigating dauer formation in P. pacificus by using genetic, experimental and biochemical tools. C. elegans and P. pacificus differ strongly in their ecology: in contrast to the soil dwelling C. elegans, P. pacificus lives naturally in close association with scarab beetles (see below). Therefore, it is likely that the dauer stage has a different role in P. pacificus and in C. elegans in nature, and it may well be expected that there will be significant differences in the molecular mechanisms of dauer formation in these species. Comparison of molecular mechanisms underlying dauer formation in the two nematodes will provide important insights into how genes are modified to enable animals to adapt to different environmental conditions.


Scientists involved:

Dr. Akira Ogawa, Postdoc
Melanie Mayer, Ph.D. Student
Amit Sinha, Ph.D. Student
Gabi Bartelmes, Technician



Introductory Reading:

Ogawa, A., Bento, G., Bartelmes, G., Dieterich, C. & Sommer, R.J. (2011): Pristionchus pacificus daf-16 is essential for dauer formation but dispensable for mouth form dimorphism. Development, 138, 1281-1284.

Sommer, R. J. & Ogawa, A. (2011): Hormone signaling and phenotypic plasticity in nematode development and evolution. Curr. Biol., 21, R758-R766.

Mayer, M.G. & Sommer, R.J. (2011): Natural variation in Pristionchus pacificus dauer formation reveals cross-preference rather than self-preference of nematode dauer pheromones. Proc. Roy. Soc. B., doi:10.1098/rspb.2010.2760.

Brown, F.D., D'Anna, I., Sommer, R.J. (2011): Host-finding behaviour in the nematode Pristionchus pacificus. Proc. Roy. Soc. B, doi:10.1098/rspb.2011.0129.

Ogawa, A., Streit, A., Antebi, A. & Sommer R. J. (2009): A conserved endocrine mechanism controls the formation of dauer and infective larvae in nematodes. Current Biology, 19, 67-71.

Featured Article:
Viney M.E. (2009): How did parasitic worms evolve? BioEssays, 31, 496-499.