Mitochondrial gene order of the freshwater bryozoan Cristatella mucedo retains ancestral lophotrochozoan features.

Bryozoans are aquatic colonial suspension-feeders abundant in many marine and freshwater benthic communities. At the same time, the phylum is under studied on both morphological and molecular levels, and its position on the metazoan tree of life is still disputed. Bryozoa include the exclusively marine Stenolaemata, predominantly marine Gymnolaemata and exclusively freshwater Phylactolaemata. Here we report the mitochondrial genome of the phylactolaemate bryozoan Cristatella mucedo. This species has the largest (21,008 bp) of all currently known bryozoan mitogenomes, containing a typical metazoan gene compendium as well as a number of non-coding regions, three of which are longer than 1500 bp. The trnS1/trnG/nad3 region is presumably duplicated in this species. Comparative analysis of the gene order in C. mucedo and another phylactolaemate bryozoan, Pectinatella magnifica, confirmed their close relationships, and revealed a stronger similarity to mitogenomes of phoronids and other lophotrochozoan species than to marine bryozoans, indicating the ancestral nature of their gene arrangement. We suggest that the ancestral gene order underwent substantial changes in different bryozoan cladesshowing mosaic distribution of conservative gene blocks regardless of their phylogenetic position. Altogether, our results support the early divergence of Phylactolaemata from the rest of Bryozoa.

Novel brominated metabolites from Bryozoa: a functional analysis.

Marine invertebrates are a promising source of novel natural products with biological activities. The phylum Bryozoa is relatively under-investigated in this context, although a number of compounds with medical potential has been discovered in recent years. Here, we report on the novel group of brominated metabolites from the bryozoan Terminoflustra membranaceatruncata, including analysis of biological activities of the tribrominated terminoflustrindole A (Cm-1) and the structures of the related dibrominated variants terminoflustrindoles B and C. Terminoflustrindole A was previously shown to have fungicidal properties. Although they vary by just one bromine group in each case from terminoflustrindole A, in this study, we report that terminoflustrindoles B and C exhibit no antimicrobial activity in the same assays. In addition to displaying antifungal activity, Terminoflustrindole A was also found to exhibit potent cytotoxic activity when tested against tumour cell lines. The gradient distribution of this compound within the bryozoan colony was demonstrated using LC-MS-analysis.