[
Cell,
2000]
Current understanding of the way in which embryonic polarity is established relies heavily on studies of maternal effect lethal mutants in D. melanogaster and C. elegans. Although the analysis in worms began in earnest about a decade after the explosion of information from flies, we now know enough about both systems to make comparisons meaningful, and to ask whether there are conserved mechanisms used for establishing embryonic polarity. Thus far, the single common feature is translational repression, which has been shown to localize important fate regulators in both systems. Now, however, in this issue of Cell, Shulman and colleagues report an analysis in D. melanogaster of the first molecule to play an important and perhaps conserved role in both animals, PAR-1.
[
Curr Biol,
2011]
Phenotypic plasticity refers to the ability of an organism to adopt different phenotypes depending on environmental conditions. In animals and plants, the progression of juvenile development and the formation of dormant stages are often associated with phenotypic plasticity, indicating the importance of phenotypic plasticity for life-history theory. Phenotypic plasticity has long been emphasized asa crucial principle in ecology and as facilitator of phenotypic evolution. In nematodes, several examples of phenotypic plasticity have been studied at the genetic and developmental level. In addition, the influence of different environmental factors has been investigated under laboratory conditions. These studies have provided detailed insight into the molecular basis of phenotypic plasticity and itsecological and evolutionary implications. Here, we review recent studies on the formation of dauer larvae in Caenorhabditis elegans, the evolution of nematode parasitism and the generation of a novel feeding trait in Pristionchus pacificus. These examples reveal a conserved and co-opted role of an endocrine signaling module involving the steroid hormone dafachronic acid. We will discuss how hormone signaling might facilitate life-history and morphological evolution.