Cléa Lerner

ACL-I, a lectin from the marine sponge Axinella corrugata: isolation, characterization and chemotactic activity.

The lectin from the marine sponge Axinella corrugata (ACL-I) was purified by affinity chromatography on rabbit erythrocytic stroma incorporated into a polyacrylamide gel followed by gel filtration on Ultrogel AcA 44 column. Purified ACL-I is a hexameric glycoprotein with a Mr of 82.3 kDa estimated by SDS-PAGE and 78.5 kDa by FPLC on Superose 12 HR column. The pI of lectin is 6.3 and ACL-I is constituted of 13.9 kDa similar subunits some of them linked by disulphide bridges. This lectin agglutinates native rabbit, goat and dog erythrocytes and in less extent human erythrocytes. The hemagglutinating activity is independent of Ca(2+), Mg(2+) and Mn(2+), but it is strongly inhibited by carbohydrates containing N-acetyl groups. ACL-I is stable up to 70 degrees C for 30 min, with optimum pH between 7 and 8, and it is also resistant to enzymatic proteolysis in vitro. In the presence of reducing or denaturant agents, the lectin activity decreases. ACL-I displays chemotactic effect on rat neutrophil in vitro which is inhibited by N-acetyl-d-glucosamine.

Biological activities of ACL-I and physicochemical properties of ACL-II, lectins isolated from the marine sponge Axinella corrugata

Lectin II from the marine sponge Axinella corrugata (ACL-II) was purified by affinity chromatography on rabbit erythrocytic stroma incorporated into a polyacrylamide gel, followed by gel filtration on Ultrogel AcA 44 column. Purified ACL-II is a lectin with an Mr of 80 kDa and 78 kDa, estimated by SDS-PAGE and by FPLC on Superose 12 HR column, respectively. ACL-II mainly agglutinates native rabbit erythrocytes and this hemagglutinating activity is independent of Ca(2+), Mg(2+) and Mn(2+), but is inhibited by d-galactose, chitin and N-acetyl derivatives, with the exception of GalNAc. ACL-II is stable for up to 65 °C for 30 min, with a better stability at a pH range of 2 to 6. In contrast, ACL-I displays a strong mitogenic and cytotoxic effect.

Novos registros e ampliação de limites meridionais de distribuição de poríferos (Porifera, Demospongiae) no Atlântico sudoeste

The southern boundaries of seven species of Brazilian coast sponges were enlarged. Two of them represent new records: Chalinula zeae de Weerdt, 2000 e Terpios manglaris Rutzler & Smith, 1993 and five were registered for the first time from the state of Santa Catarina: Callyspongia (Toxochalina) pseudotoxa Muricy & Ribeiro, 1999; Mycale (Carmia) magnirhaphidifera van Soest, 1984; Hymeniacidon heliophila Parker, 1910; Monanchora arbuscula (Duchassaing & Michelotti, 1864) and Scopalina ruetzleri (Wiedenmayer, 1977). The taxonomic description of species is also provided and the three latter were described for the first time from the Brazilian coast, since other authors only cited it.

Antibiofilm activity of Cobetia marina filtrate upon Staphylococcus epidermidis catheter-related isolates

We report the antibiofilm activity by the sponge-associated bacterium Cobetia marina upon Staphylococcus epidermidis clinical isolates obtained from central venous catheters. Antibiofilm activity/antimicrobial susceptibility correlation might predict the action of the metabolite(s) upon Staphylococcus epidermidis in the clinic, making it a possible adjuvant in therapies against biofilm-associated infections.

Family Guitarridae Dendy, 1924

Guitarridae Dendy (Demospongiae, Poecilosclerida, Mycalina) includes species with typical mycalostyles and sigmancistras, lacking tridentate chelae, and having restricted architectural specialization shown by their megascleres (e.g., absence of echinating megascleres). Microscleres consist of placochelae-derivatives (placochelae, biplacochelae, dischelae and/or tetrapocillas), uniting genera irrespective of their disparate skeletal arrangements. The family includes seven nominal genera of which four are valid. A key for the valid genera is given.

Immunohistochemical localization of an N-acetyl amino-carbohydrate specific lectin (ACL-I) of the marine sponge Axinella corrugata.

The N-acetyl amino-carbohydrate specific lectin (ACL-I) was previously identified and purified by us from the marine sponge Axinella corrugata (phylum Porifera, class Demospongiae). The distribution of the specific lectin within the tissue of the sponge was studied by bright-field optical microscopy immunohistochemistry in order to better understand its physiological role in the sponge. Polyclonal antibodies were raised against purified ACL-I in mice and tested by Western blot technique. The immunohistochemical analysis of ACL-I in cross sections of A. corrugata showed that this lectin is found inside the denominated spherulous cells, which contain vesicles that store the lectin. Some evidence is shown that ACL-I might also be present in the extracellular matrix. It was not possible to demonstrate by the immunohistochemical technique if ACL-I is colocalized in both the plasma membrane and in the cytoplasm of the spherulous cells.

New records of the genus Agelas Duchassaing & Michelotti, 1864 (Porifera, Agelasida) off the Amazon River mouth, Brazil, Southwestern Atlantic

This work provides new information on agelasid sponges found on the continental shelf off northern Brazil. Agelas sceptrum (Lamarck, 1815) and Agelas wiedenmayeri Alcolado, 1984 have their first record for the Brazilian coast. Agelas dispar Duchassaing & Michelotti, 1864 and Agelas schmidti Wilson, 1902, previously recorded from Brazil, are cited for the first time off the mouth of the Amazon River.

Monanchora brasiliensis sp. nov. (Poecilosclerida: Demospongiae), new crambeid from the Brazilian coast, south-western Atlantic, with monodentate anchorate chelae

A new Brazilian endemic Monanchora is described, M. brasiliensis sp. nov. It is clearly distinct from any other species in the genus by the monodentate shape of its anchorate isochelae, and its smooth, centrotylote and strongyloid microrhabds. Monodentate anchorate isochelae are relatively common, normally abundant, and represent the main diagnostic character for recognizing the new species, but microrhabds are usually rare and may be even absent. Monanchora brasiliensis sp. nov. can be further differentiated from other Atlantic species of the genus in eventually showing tetralobate branches and a skeleton formed by well-defined honey-coloured spongin fibres. The affinities of the new species with other crambeids and the nature of anchorate isochelae, microrhabds as well as the megascleres in defining Monanchora are discussed. An amended diagnosis for the genus is proposed.

Morphological and molecular systematics of the ‘Monanchora arbuscula complex’ (Poecilosclerida : Crambeidae), with the description of five new species and a biogeographic discussion of the genus in the Tropical Western Atlantic

Abstract. Monanchora Carter, 1883 is a genus of shallow-water marine sponges comprising 16 species distributed worldwide, two of them in the Tropical Western Atlantic (TWA): M. arbuscula (Duchassaing & Michelotti, 1864) and M. brasiliensis Esteves, Lerner, Lôbo-Hajdu & Hajdu, 2012. The former species stands out as one of the most variable demosponges, and is very similar in spicule complement and in secondary metabolite chemistry to the Mediterranean/eastern Atlantic Crambe crambe (Schmidt, 1862), type species of Crambe Vosmaer, 1880. The aim of the present study was to revise the genus Monanchora in the TWA. In addition, we critically analyse the monophyly of Crambe and Monanchora. Maximum Likelihood and Bayesian Inference analyses of 28S and 16S rRNA sequences of the latter genera, and a redescription of the ‘M. arbuscula complex’, revealed three species: M. arbuscula s.s., M. coccinea, sp. nov. and a new species of Acarnidae – Iophon parvachela, sp. nov. Three other new species from the TWA previously assigned to Monanchora were revealed by morphological analyses, and are also described: M. bahamensis, sp. nov., M. megasigmifera, sp. nov. and a new species of Chondropsidae – Batzella catarinensis, sp. nov. A key for species identification is provided. Our results suggest that the Eastern Brazil and Southeastern Brazil Ecoregions may represent centres of diversity for Monanchora in the TWA.