The Occurrence of Laminarionema elsbetiae (Phaeophyceae) on Rhodymenia pseudopalmata (Rhodophyta) from the Patagonian Coasts of Argentina: Characteristics of the Relationship in Natural and Experimental Infections, and Morphology of the Epi-endophyte in Unialgal Free Cultures

The occurrence of Laminarionema elsbetiae (Ectocarpaceae, Phaeophyceae), as epi-endophyte of Rhodymenia pseudopalmata (Rhodymeniales, Rhodophyta), described from Santa Isabel, Rawson, Argentina. L. elsbetiae grows in the host tissues forming epi-endophytic relationship in the epidermal, cortical and medullar layers. Epiphytic thalli of L. elsbetiae were unbranched filaments emerging from hostis surface. Reproductive structures of L. elsbetiae on the host were absent. On the contrary, free cultured individuals formed different reproductive structures. Macrozoosporangia containing a single large motile zoospore originated from vegetative cells, they were conical to cylindrical in shape, 30-50 in length and 18-20 in wide. Uniseriate plurilocular zoosporangia were cylindrical shape, 40 in length and 10-13 in wide. Sexual fusion was not seen. In mixed cultures of L. elsbetiae with R. pseudopalmata fronds, L. elsbetiae infected the host, grew as in natural host and, formed macrosporangia between host subcortical cells. Gametophytes of L. elsbetiae were filaments with diffuse growth, branched with a branch pattern alternate or opposite. Gametangia were plurilocular, uni or biseriate and lateral. When mature they contained 2 to 6 isogametes. The presence L. elsbetiae on R. pseudopalmata could be defined as an epi-endophytic relationship. The percentage of infection of R. pseudopalmata thalli by L. elsbetiae was 34%.A25% of the infected thalli presented a low, non-symptomatic level infection, whereas a 62% and a 13% of them exhibited respectively moderate and high indexes of infection.Fil: Gauna, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Caceres, Eduardo Jorge. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ficología y Micología; Argentin

Secondary zoospores in the algal endoparasite Maullinia ectocarpii (Plasmodiophorea).

The present paper deals with the ultrastructure of zoospores produced by the plasmodiophorid Maullinia ectocarpii , living in the marine algal host Ectocarpus siliculosus. The zoospores described here are very similar to secondary zoospores of Polymyxa graminis and Phagomyxa sp. (the latter an algal endopara- site, also). Our results indicate that M. ectocarpii produces two types of plasmodia, and suggest that is a species with a complete life cycle, as it is known for all the Plasmodiophormycota that have been studied. Sporogenic and sporangial plasmodia produce, respectively, primary zoospores with parallel flagella within thick walled resting sporangia, and secondary zoospores with opposite flagella within thin walled sporangia.Fil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur; ArgentinaFil: Caceres, Eduardo Jorge. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ficología y Micología; ArgentinaFil: Westermeier, Renato. Universidad Austral de Chile; ChileFil: Muller, Dieter G.. Universität Konstanz; Alemani

Estudio preliminar de los efectos del dragado sobre aspectos bio-sedimentológicos de las planicies de marea

Se llevó a cabo un estudio preliminar interdisciplinario donde se relacionan resultados biológicos y sedimentológicos para analizar el efecto del dragado a inyección de agua, un método recientemente implementado a nivel mundial. Los resultados de este estudio son pioneros en evaluar las consecuencias del dragado sobre las planicies de marea. Las conclusiones obtenidas permiten señalar que las tareas de dragado influyen en las comunidades microfitobentónicas de las planicies de marea, afectando por consiguiente la estabilidad de los sedimentos que son factibles de ser transportados y depositados en el medio circundante. Los resultados y su posterior análisis a través de componentes principales indican que la alteración ambiental por el dragado hidráulico afecta sólo la zona vecina al sector dragado y parece no alcanzar una distancia perpendicular al canal dragado de 1000 m sobre las planicies de marea adyacentes.A preliminary interdisciplinary study was carried out relating biologic to sedimentologic results with the objective of analyze the water injection dredging effect, a method recently applied in the world. These results are pioneer in the evaluation of consequences of dredging over the tidal plains. The conclusions let to state that the dredge works affect the microphytobenthos communities lying at the tidal plains, and consequently, the stability of the sediments that might be transported and deposited in the surroundings. The results of a statistical method (Principal Component) pointed that the environmental effect produced by dredging only influence the adjacent zone, being negligible in the tidal flat at a distance of 1000 m perpendicular to the dredged channel.Fil: Pizani, Natalia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur; ArgentinaFil: Cuadrado, Diana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur; ArgentinaFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur; Argentin

First record of Spermatozopsis similis (Chlorophyta) in a marine environment

El objetivo del presente trabajo es registrar por primera vez la presencia de Spermatozopsis similis H.R.Preisig et M.Melkonian en un ambiente marino y describir su morfología y abundancia en la Ría del Jabalí (Bahía Anegada, Buenos Aires, Argentina). Se realizaron muestreos mensuales entre los meses de junio y noviembre de 2006 y las muestras se observaron bajo microscopio óptico y electrónico de barrido. Los ejemplares de S. similis presentaron células biflageladas fusiformes y levemente espiraladas, con flagelos de largo desigual. S. similis fue un componente importante del fitoplancton en la Ría del Jabalí entre junio y agosto de 2006, alcanzando su máxima abundancia durante agosto (6770 cél.ml-1), durante este período se observaron valores muy altos y fluctuantes en la salinidad. Este trabajo constituye el primer registro de Spermatozopsis similis en un ambiente marino.The objective of the present study is to report for the first time the occurrence of Spermatozopsis similis H. R. Preisig et M. Melkonian in a marine environment, describing the morphology and its abundance in Ría del Jabalí; Bahía Anegada, Buenos Aires, Argentina. Samples were taken monthly between June and November 2006 and were observed under light and scanning electron microscope. Specimens of S. similis showed biflagellate, fusiform and slightly spiraled cells, with flagella of unequal length. S. similis was an important component of phytoplankton in Ría del Jabalí between June and August 2006, reaching its maximum abundance in August (6 770 cél.ml-1), during this period there were observed very high and fluctuating values of salinity. This paper is the first record of S. similis in a marine environment.Fil: Fernandez, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Gauna, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Croce, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología Acuática; Argentin

Dictyota dichotoma (phaeophyceae) methanolic extracts exhibit antitumoral effects on breast cancer cells and induce osteoblasts differentiation

There is a growing interest in macroalgae as natural products with antioxidant and anticancer activity. In this work, we studied the anti-tumoral effect of an algal extract (AE) derived from the marine alga Dictyota dichotoma on human breast cancer cells (MCF-7). We also evaluated the cytotoxic effects on non-tumorigenic cells and the effects on ostoblastogenesis in vitro. We found that the AE contains high levels of polyphenols and anti-oxidant activity measured by DPPH and Folin-Ciocalteu methods, respectively. Using trypan blue and MTS assays we demonstrated a significant inhibition of MCF-7 cell proliferation and viability. The changes in protein phosphorylation levels were examined through Western blot analysis, finding a decrease of phosphorylated AKT (Ser473) and its target molecule BAD (Ser136). In addition, AE inhibits cell migration determined through the wound healing assay and decreases cellular adhesion at all concentrations probed. Interestingly, AE does not affect the number and morphology of normal osteoblastic human cells, indicating its selectivity. Moreover, using colorimetric methods, we found that low doses of AE increase the production of osteoblastogenesis markers. These findings indicate that D. dichotoma is a valuable source of bioactive compounds for its regulatory effects on processes involved in metastasis and healthy effects in osteoblasts.Fil: Lezcano, Virginia Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Mariani, Florencia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Fernández, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Parodi, Elisa Rosalia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: Morelli, Susana Ana. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Química Biológica; Argentin

Senecio bonariensis Hook. & Arn. promising arsenic phytoextractor from water in laboratory and field trials

The use of plant species to cleanse groundwater with excessive concentrations of arsenic (As) derived from contact with weathered materials has become a valuable option to treat it. The aim of this work was to analyze the bioaccumulation capacity of As of Senecio bonariensis (Asteraceae) through controlled laboratory tests and uncontrolled trials in the field in order to generate a low cost method applicable in rural areas that do not have systems of water treatments. Plants collected from the natural environment were arranged in hydroponic crops under controlled and uncontrolled conditions, in the first case with increasing concentrations of As for 45 days, and in the second, with a constant concentration of As for a period in a range between 45 and 90 days. The plants were processed and dried for the measurement of As. In both tests, in all the samples there was a noticeable accumulation of As, generally greater in roots than in leaves. Under controlled conditions the plants accumulated more As in relation to greater concentration of this element in the water. In all the trials a high bioaccumulation of As was found, which turns the plant into a hyperaccumulator. Due to the ability of S. bonariensis to accumulate As, and even more because of the great biomass produced by this species, it becomes an excellent one to be used for the remediation of arsenical waters.Fil: Pérez Cuadra, Vanesa. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Cambi, Viviana Nora. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Espósito, Martín Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Agronomía; ArgentinaFil: Sica, María Gabriela. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Plantas Vasculares; ArgentinaFil: Verolo, Magalí. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Siniscalchi, Amira Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Parodi, Elisa Rosalia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

Life cycle of Punctaria latifolia (Chordariaceae, Phaeophyceae) from the coast of Buenos Aires Province, South America

The objective of this study was to describe the morphology of Punctaria latifolia individuals from the natural environment, their life cycle under culture conditions and the caryology of different phases. The life cycle of Punctaria latifolia was studied under culture conditions (140 μmol m-2 s-1; 12 h/12 h; 21 ± 1 °C). Fertile sporophytes were collected in the intertidal zone of Bahía San Blas (Buenos Aires, Argentina, South America), in August and December 2003. These macroscopic laminar plants were found adhered to the rocky substrate and on Spartina alterniflora plants. Sporophytes from the natural environment presented both plurilocular and unilocular sporangia, which released plurispores and unispores, respectively. The asexual reproduction was evidenced by the germination of unispores by formation of a single - pole germination that formed microscopic filamentous gametophytes. Terminal and intercalar gametangia released isogametes. Zygotes reconstituted the macroscopic phase. Chromosome counts gave 16 and 8 for sporophytic and gametophytic phases, respectively. This species presented a haplodiplobiontic heteromorphic life cycle as well as a direct type, when plurispores produced plethysmothalli.Fil: Gauna, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología Acuática; ArgentinaFil: Parodi, Elisa Rosalia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología Acuática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

Green epi-endophytes in Hymenena falklandica (Rhodophyta) from the Patagonian coasts of Argentina: Preliminary observations.

The occurrence of epi-endophyte algae in Hymenena falklandica J. G. Ag. Ex Kylin (Rhodophyta) is reported in Argentina. Epicladia heterotricha (Yarish) Nielsen (Chlorophyceae) revealed a 100% prevalence of occurrence, particularly in the basal region of the host. Low (14%), moderate (28%) and high (58%) severity degrees of infection were also registered for E. heterotricha. Pseudendoclonium submarinum Wille (Chlorophyceae) exhibited a lower frequency of occurrence, close to 3%. The developmental morphology and dynamics of E. heterotricha and P. submarinum were investigated under unialgal as well as bialgal culture conditions. The experimental infection of H. falklandica by E. heterotricha demonstrated that E. heterotricha initially behaves as epiphytic but with endophytic filaments growing into the cortex of the host during late infection. P. submarinum was found to be exclusively epiphytic, with no development of endophytic filamentous systems. The present study reports the first lines of evidence of an epidemiological study conducted with the purpose of comparing both the prevalence and effects of algal epi-endophytic organisms in H. falklandica in the southern coasts of Argentina.Fil: Gauna, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin

The turf-forming alga Gelidium crinale (Florideophyceae, Rhodophyta) on Atlantic Patagonian coasts

We describe for the first time the morphology of Gelidium crinale from its natural habitat in Atlantic Patagonia with special consideration of diagnostic characters. Observations and morphometric measurements were done on fresh specimens using scanning electron and inverted light microscopy. This report is a new record for Atlantic Patagonian coasts. The thalli comprise prostrate and erect axes; they are subterete at the base and compressed to flattened at the apices. The basal parts are scarcely and irregularly branched, while the apical parts are highly ramified and subdichotomously branched. The lengths of thalli and the ramification patterns differ from previous descriptions, and were variable between seasons and life history phases. ´Brush-like´ haptera confirmed the identity of the algae as members of the Gelidiaceae. Internal rhizoidal filaments are abundant and distributed in groups throughout the medulla. The life history was of the ´Polysiphonia -type´ ; occurrences of carposporophytes and tetrasporophytes were variable.Fil: Croce, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur; ArgentinaFil: Parodi, Elisa Rosalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentina. Universidad Nacional del Sur; Argentin