Polyphyly of the genus Axinella and of the family Axinellidae (Porifera: Demospongiaep).

The genus Axinella is difficult to define on the basis of morphological characters and includes a heterogeneous assemblage of species. Several previous authors have suspected the polyphyly of both this genus and the family Axinellidae. To clarify the phylogeny of Axinellidae and Axinella, we propose a new hypothesis based on two molecular markers.

Conservation and phylogeny of a novel family of non-Hox genes of the Antp class in Demospongiae (porifera).

A survey across the most basal animal phylum, the Porifera, for the presence of homeobox-containing genes led to the isolation of 24 partial or complete homeobox sequences from 21 sponge species distributed in 15 families and 6 orders of Demospongiae. All the new sequences shared a high identity/similarity with EmH-3 (Ephydatia muelleri), a non-Hox gene from the Antp class. The Demox sequences, EmH-3, and related homeodomains formed a well-supported clade with no true affinity with any known bilaterian family, including the Tlx/Hox11 family, suggesting that the EmH-3 family of genes, comprising 31 members, represents a novel family of non-Hox genes, called the Demox family, widespread among Demospongiae.

Primary cultures from the marine sponge Xestospongia muta (Petrosiidae, Haplosclerida).

In the context of the investigations on the origin and in vitro production of bioactive compounds, primary cultures were developed from ectosomal and choanosomal cell suspensions from the sponge Xestospongia muta. Dissociated cells aggregated and reorganized into a striking reticulated network of cells, typical for X. muta.

Cellular location of (2R, 3R, 7Z)-2-aminotetradec-7-ene-1, 3-diol, a potent antimicrobial metabolite produced by the Caribbean sponge Haliclona vansoesti.

The Caribbean sponge Haliclona vansoesti has been found to contain large amounts of a new sphingosine derivative, (2R, 3R, 7Z)-2-aminotetradec-7-ene-1, 3-diol (compound 1). To determine the localization of this compound within the organism, cell distribution and quantitative determination of the aminodiol content of cell fractions obtained by differential centrifugation have been performed. Results show that choanocytes and archaeocytes are the major sponge cell types and that H.

Retinoic acid down-regulates the expression of EmH-3 homeobox-containing gene in the freshwater sponge Ephydatia muelleri.

The effects of retinoic acid (RA), a common morphogen and gene expression regulator in vertebrates, were studied in the freshwater sponge Ephydatia muelleri, both on morphogenesis and on the expression of EmH-3 homeobox-containing gene. At 0.3 microM, RA had no noticeable influence on sponge development, slightly up-regulating EmH-3 expression.

Temporal and spatial expression of EmH-3, a homeobox-containing gene isolated from the freshwater sponge Ephydatia muelleri.

Homeoboxes have been particularly valuable in identifying genes involved in development. This prompted us to look for homeobox-containing genes in sponges, the most primitive metazoans, and to explore the potential role of these genes in their development. Using the reverse transcription polymerase reaction (RT-PCR), we analyzed the expression of EmH-3 homeobox-containing gene at different stages of development, and in different cell-type populations.

[Demonstration of glycocalyx formation in vitro in Citrobacter freundii, Proteus mirabilis and Planococcus sp.: the effect of polyosidases].

Three bacterial species of different origin, Citrobacter freundii, Proteus mirabilis and Planococcus sp., formed glycocalyx in vitro and thereby showed that the phenomena does not only occur in vivo contrary to the opinion of many authors. The glycocalyx was produced in the attachment processes used or both extra- and intercellular attachment.