Ongoing phytoplankton monitoring programs over the last 12 years in the northern Adriatic Sea showed that the diatom genus Bacteriastrum is an important component of the pelagic diatom assemblage. The main goals of this study were to identify which Bacteriastrum species occur in the northern Adriatic Sea and describe their distributions. Bacteriastrum comosum and B. hyalinum f. princeps were rare, while B. delicatulum, B. hyalinum, and B. mediterraneum were frequently present, together with the newly proposed species B. jadranum, described herein. This new species is weakly silicified and is mainly characterized by a large aperture between each cell of the filament. Cells are connected to each other by 8–12 setae, which cross at a distance equivalent to the diameters of 2–3 cells. There is no difference in the orientation of the setae on the two terminal cells, hence the species is placed in the section Isomorpha. The new species was recorded throughout the study area, in both coastal and offshore waters, with higher cell abundances in the vicinity of the Po River during the September–October period. The maximum cell abundance of B. jadranum was 244.2×103cells l-1in the surface waters at 44.75666667ºN, 12.75ºE in September 2006, sometimes representing up to 46% of the entire phytoplankton assemblage, as recorded in the surface waters at 45.06833333ºN, 13.515ºE in October 2008.

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Finkel-Biskis-Reilly murine sarcoma virus (FBR-MuSV) ubiquitously expressed (FAU) gene is down-regulated in human prostate, breast and ovarian cancers. Moreover, its dysregulation is associated with poor prognosis in breast cancer. Sponges (Porifera) are animals without tissues which branched off first from the common ancestor of all metazoans. A large majority of genes implicated in human cancers have their homologues in the sponge genome. Our study suggests that FAU gene from the sponge Suberites domuncula reflects characteristics of the FAU gene from the metazoan ancestor, which have changed only slightly during the course of animal evolution. We found pro-apoptotic activity of sponge FAU protein. The same as its human homologue, sponge FAU increases apoptosis in human HEK293T cells. This indicates that the biological functions of FAU, usually associated with “higher” metazoans, particularly in cancer etiology, possess a biochemical background established early in metazoan evolution. The ancestor of all animals possibly possessed FAU protein with the structure and function similar to evolutionarily more recent versions of the protein, even before the appearance of true tissues and the origin of tumors and metastasis. It provides an opportunity to use pre-bilaterian animals as a simpler model for studying complex interactions in human cancerogenesis.

In this study we analyze the calcarean sponge diversity of the Adriatic Sea, the type locality of some of the first described species of calcarean sponges. Morphological and molecular approaches are combined for the taxonomic identification. Our results reveal six species new to science and provisionally endemic to the Adriatic Sea (Ascandra spalatensis sp. nov., Borojevia croatica sp. nov., Leucandra falakra sp. nov., L. spinifera sp. nov., Paraleucilla dalmatica sp. nov., and Sycon ancora sp. nov.), one species previously known only from the Southwestern Atlantic (Clathrina conifera), and three already known from the Adriatic Sea (Ascaltis reticulum, Borojevia cerebrum, and Clathrina primordialis). We confirm the presence of the alien species Paraleucilla magna in the Adriatic and again record Clathrina blanca, C. clathrus, and C. rubra. We emend the description of the genus Ascaltis, propose a lectotype for Borojevia cerebrum and synonymise B. decipiens with B. cerebrum. A checklist of all calcarean species previously and currently known from the Adriatic Sea (39 species) is given. The Central Adriatic is indicated as the richest calcarean sponge fauna sector; however, the biodiversity of this class is underestimated in the whole Adriatic Sea and new systematic surveys are desirable.

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Abstract. Bruton's tyrosine kinase (Btk) is a member of Tec family of protein tyrosine kinases. It is expressed in B cells and myeloid cells in humans and it is crucial for maturation of B-lineage lymphoid cells. Mutations in the gene encoding human Btk result in hereditary immunodeficiency X-linked agammaglobulinemia. Sponge proteins can probably reflect characteristics of the ancestral metazoan homologues before their diversifications and specializations in complex animals.Gene coding for sponge Btk-like protein was fully characterized and its structure was compared with homologous genes from other organisms. Kinase activity of sponge protein was compared to human Btk activity.We showed that sponge Btk-like gene is probably the most ancient member of Tec family while other members arose from the ancestral gene present in chordate ancestor. The ancestral-type protein was structurally and functionally similar to the highly sophisticated enzyme it is today, whose functions are usually associated with higher Metazoa. (doi: 10.5562/cca1862)

Ribosomal protein genes (RPGs) are a powerful tool for studying intron evolution. They exist in all three domains of life and are much conserved. Accumulating genomic data suggest that RPG introns in many organisms abound with non-protein-coding-RNAs (ncRNAs). These ancient ncRNAs are small nucleolar RNAs (snoRNAs) essential for ribosome assembly. They are also mobile genetic elements and therefore probably important in diversification and enrichment of transcriptomes through various mechanisms such as intron/exon gain/loss. snoRNAs in basal metazoans are poorly characterized. We examined 449 RPG introns, in total, from four demosponges: Amphimedon queenslandica, Suberites domuncula, Suberites ficus and Suberites pagurorum and showed that RPG introns from A. queenslandica share position conservancy and some structural similarity with “higher” metazoans. Moreover, our study indicates that mobile element insertions play an important role in the evolution of their size. In four sponges 51 snoRNAs were identified. The analysis showed discrepancies between the snoRNA pools of orthologous RPG introns between S. domuncula and A. queenslandica. Furthermore, these two sponges show as much conservancy of RPG intron positions between each other as between themselves and human. Sponges from the Suberites genus show consistency in RPG intron position conservation. However, significant differences in some of the orthologous RPG introns of closely related sponges were observed. This indicates that RPG introns are dynamic even on these shorter evolutionary time scales.

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