Metagenomic analysis of museum nudibranch specimens reveals uncultured symbionts with biosynthetic gene clusters (microbiomejournal.biomedcentral.com)

• Metagenomics of 30-year-old museum specimens doubled nudibranch microbiome data
• Two novel uncultured symbionts discovered in Polycera and Felimare: Candidatus Polyceribacter and Felimaribacter
• Symbionts encode diverse biosynthetic gene clusters matching host metabolites
• Study validates museomics for symbiosis research in rare marine invertebrates

"Researchers used metagenomics on ethanol-preserved nudibranch specimens, some archived for up to 30 years, doubling available nudibranch microbiome datasets. They discovered two previously unknown symbionts, Candidatus Polyceribacter and Candidatus Felimaribacter, in the genera Polycera and Felimare. These symbionts encode diverse biosynthetic gene clusters consistent with metabolites previously reported from their hosts, indicating long-term evolutionary specialization. The study establishes museomics as a robust framework for symbiosis research in rare marine invertebrates, revealing that dominant uncultured symbionts are rare overall but present in specific lineages."