Meeting Abstract
Chitons possess clusters of sensory cells called aesthetes within their eight overlapping shell plates. In some polyplacophoran species within a large unresolved subgroup, Chitonina, aesthetes are modified to include an eyespot, and in others, aesthetes are present in addition to eyes with a lens and retina. To address the evolution of complexity in chiton eyes, it is necessary to phylogenetically test the relationships between chitons with eyespots and chitons with lenses. Relationships within Chitonina have been difficult to resolve with traditional molecular markers, limiting our ability to test evolutionary hypotheses. To enable us to use ethanol-preserved collections, we took a target-capture approach. We designed a set of 19,980 probes using transcriptome data and predicted exon boundary information using three mollusk genomes (Lottia, Octopus, and Crassostrea). Preliminary maximum likelihood analyses show strong support for super-family relationships, and suggest the possibility of multiple origins for lenses in chitons. However, hypothesis testing and ancestral state reconstructions are necessary to further investigate this result.
