A gathering of minds: expanding understanding of the origins of biological diversity and the evolution of developmental mechanisms

This year, a record number attended the Annual Society of Integrative and Comparative Biology (3-7 January 2012) meeting in Charleston, South Carolina. The meeting offered a wide range of talks about the evolution of development, as well as sessions in the other SICB divisions (animal behavior, comparative biomechanics, comparative endocrinology, comparative physiology/biochemistry, ecology/evolution, invertebrate zoology, neurobiology, phylogenetics/comparative biology and vertebrate morphology). This report summarizes a few of the many excellent presentations (800+ talks/600+ posters), focusing on those in the evolution of development.Among the lower metazoans, understanding of the ctenophores is clearly progressing. William Browne in collaboration with Christine Schnitzler, Derek Gildea, Anh-Dao Nguyen, E. Maxwell, Joseph Ryan and Andreas Baxevanis (University of Miami, USA; NHGRI/NIH, USA) presented preliminary analysis of next-generation RNAseq data from Mnemiopsis leidyi. In this study, they examined mRNA and smRNA expression at two developmental stages, zygotes 0 to 1 hours post fertilization (hpf) and late embryonic stages (15 to 30 hpf). Interestingly, they found elevated levels of two Kruppel-like factor (Klf) genes in zygotes. In light of J. Jiang's recent work showing that Klf is required for self-renewal of mouse embryonic stem (ES) cells and that ES cells depleted of Klf2, Klf4 and Klf5 undergo differentiation, Browne et al. suspect that ctenophore maternal Klf transcripts may aid in regulating pluripotency. They have also found a complex zygotic transcriptome, suggesting that maternal transcripts strongly influence early cell fate decisions.Extensive analysis of another ctenophore species, Pleurobrachia bachei, was performed by Leonid Moroz, Andrea Kohn, Matthew Citarella, Anastasia Grigorenko, Kevin Kocot, Ken Halanych and Evgeny Rogaev (University of Florida, USA; University of Massachusetts Medical School, USA; University of Alabama, USA). These in