Meeting Abstract
The role of DNA methylation in invertebrate gene regulation, if any, remains uncertain. We examine this question using axial and radial polyps of the coral Acropora millepora as a model for gene regulation. These dimorphic polyp types represent a key innovation of the Acropora genus, giving it uniquely rapid growth rates and morphological diversity. We compare gene expression and DNA methylation between these two polyp types from two colonies, assaying gene expression using Tag-seq, and DNA methylation using three different methods: whole genome bisulfite sequencing (WGBS), Methylation binding domain sequencing (MBD-seq), and methylation-selective restriction enzymes (MethylRAD). We begin by benchmarking the three methylomic assays, showing that they provide similar readouts of DNA methylation. We then examine the covariation between methylation and transcription, both between polyp types and coral colonies. Finally, we take a molecular evolutionary approach to identify genes under positive selection in the lineage preceding Acropora diversification. We compare these genes with those showing differential expression and methylation between polyp types to identify candidate genes involved in the evolution of polyp dimorphism key innovation.
