https://www.selleckchem.com/products/ro5126766-ch5126766.html Most byssal genes are in small families, with several amino acid substitutions between paralogs. Byssal proteins of zebra mussels and related quagga mussels (D. rostriformis) are divergent, suggesting rapid evolution typical of proteins with repetitive low complexity domains. Opportunities abound for proteomic and genomic work to further our understanding of this textbook example of a marine natural material. A priority should be invasive bivalves, given the role of byssal attachment in the spread of, and ecological and economic damage caused by zebra mussels, quagga mussels and others. This article is part of the Theo Murphy meeting issue 'Molluscan genomics broad insights and future directions for a neglected phylum'.Mollusca are the second largest and arguably most diverse phylum of the animal kingdom. This is in sharp contrast to our very limited knowledge concerning epigenetic mechanisms including DNA methylation in this invertebrate group. Here, we inferred DNA methylation patterns by analysing the normalized dinucleotide CG content in protein-coding sequences and identified DNA methyltransferases (DNMT1 and 3) in published transcriptomes and genomes of 140 species across all eight classes of molluscs. Given the evolutionary age and morphological diversity of molluscs, we expected to find evidence for diverse methylation patterns. Our inferences suggest that molluscs possess substantial levels of DNA methylation in gene bodies as a rule. Yet, we found deviations from this general picture with regard to (i) the CpG observed/expected distributions indicating a reduction in DNA methylation in certain groups and (ii) the completeness of the DNMT toolkit. Reductions were evident in Caudofoveata, Solenogastres, Polyplacophora, Monoplacophora, as well as Scaphopoda. Heterobranchia and Oegopsida were remarkable as they lacked DNMT3, usually responsible for de novo methylation, yet showed signs of DNA methyl