Meeting Abstract
The question of how novelty arises has lurked in the background of evolutionary biology for decades. One common hypothesis suggests that novel traits arise with the origin of novel genes. Support for this ‘novel genes-novel traits’ hypothesis largely comes from studies that have identified taxon-restricted genes (which lack identifiable orthologs outside of the taxon of interest) as critical regulators of novel trait identity. A clear example supporting this argument is the role of minicollagen, a cnidarian-specific protein, in the development of the cnidocyte (stinging cell); but examples such as these are rare. We take a different approach to this question; specifically, we examine the role of lineage-specific duplications of conserved gene families on the development and diversification of cnidocytes from the sea anemone Nematostella vectensis. Using functional and comparative genomics and phylogenetics, we show that different cnidocyte types express unique assemblages of paralogs of common/shared genes. Further, we provide evidence that duplication and diversification of effector genes (rather than transcription factors) may play a critical role in supporting the diversification of cell identity. Together, our results imply that general orthology analysis might fail to accurately characterize the transcriptional environment of similar cell types and may, therefore, underestimate the role of gene duplication in facilitating cell diversification.
