ИСТИНА

The species–rich taxon Cladobranchia (Nudibranchia, Heterobranchia) currently comprises approximately 98 genera from 22 families of exclusively marine gastropods. Despite attempts to shed light on the evolution of the group, the phylogenetic position of most of its families is still subject to debate. While past efforts of gaining a better understanding of the relationships within Cladobranchia using barcoding gene approaches did not result in phylogenies with satisfactory resolution, the first phylogenies using transcriptomic multi–gene approaches only covered a limited number of species omitting many families with uncertain position. To overcome this problem, we sequenced the transcriptomes of 21 species of heterobranch sea slugs and combined our data with raw reads from 40 species of Heterobranchia available from public databases. In order to obtain a high number of genes suitable for phylogenetic analyses, we assembled the raw reads using six different transcriptome assembly tools. For each species, we identified the best assembly using a variety of descriptive parameters. We then searched the assemblies for orthologous genes that are presumed to be single–copy in molluscs and combined them in a phylogenetic supermatrix. Here we show our first results from the broadened dataset.