Mobilizing molluscan models and genomes in biology

Abstract

Molluscs are among the most ancient, diverse, and important of all animal taxa. Even so, no individual mollusc species has emerged as a broadly applied model system in biology. We here make the case that both perceptual and methodological barriers have played a role in the relative neglect of molluscs as research organisms. We then summarize the current application and potential of molluscs and their genomes to address important questions in animal biology, and the state of the field when it comes to the availability of resources such as genome assemblies, cell lines, and other key elements necessary to mobilising the development of molluscan model systems. We conclude by contending that a cohesive research community that works together to elevate multiple molluscan systems to 'model' status will create new opportunities in addressing basic and applied biological problems, including general features of animal evolution. This article is part of the Theo Murphy meeting issue 'Molluscan genomics: broad insights and future directions for a neglected phylum'.

Keywords: evolution; genomics; model organism; mollusc.

Figure 1.

Relationships among the major lineages of Mollusca, relative to other Lophotrochozoa, and Ecdysozoa and Deuterostomia outgroups. The structure of the phylogeny is based on that presented by Kocot et al. [2], using a phylogenomic dataset. Representative organismal images provided by Emily Jalinsky. (Online version in colour.)

Figure 2.

Idealized ‘ELCTR’ criteria for the making of a model mollusc. Images from top: Cepaea nemoralis at the University of Nottingham (Daniel Ramos Gonzalez); Potamopyrgus antipodarum laboratory culture at the University of Iowa (Justin Torner); attendees at the Royal Society ‘Pearls of Wisdom’ molluscan genome meeting 2019 (Liam Helm); CRISPR-Cas9 cartoon (National Human Genome Research Institute, CC-BY-2.0); investigators using the MolluscDB [8] database (Chelsea Higgins). (Online version in colour.)

Figure 3.

Representative molluscs used in research and highlighted in this work. The classes Gastropoda (including pond snail Lymnaea stagnalis, bloodfluke planorb Biomphalaria glabrata, New Zealand mud snail Potamopyrgus antipodarum, slipper snail Crepidula fornicata, cone snails Conus spp.), Bivalvia (including various clams, mussels, scallops) and Cephalopodia (including Octopus) all include several model species. In comparison, there are no species that could be described as models in the other classes and groups, including the Scaphopoda, Monoplacophora, Aplacophora and Polyplacophora. Image credit: Emily Jalinsky. (Online version in colour.)