Picoeukaryotic diversity in Argentinean sea costal site studied by molecular approaches

CUMINO, A; COVACEVICH, F; SILVA, R; NEGRI, R; SALERNO, G

Pinamar, Buenos Aires

Workshop; XLI Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y de Biología Molecular (SAIBBM); 2005

Sociedad Argentina de Investigación Bioquímica y de Biología Molecular (SAIBBM)

We studied the diversity of picoeukaryotes of samples collected from surface water at a coastal fixed station EPEA (38º28’S-57º41’W). Sequences of 18S rDNA environmental picoeukaryotes were retrieved and molecular fingerprinting techniques (RFLP and DGGE) were used to analyze the seasonal changes in the taxonomic composition. Genetic libraries were constructed and the clones that produced different RFLP pattern were sequenced. Phylogenetic tree constructed with ribosomal minilibraries revealed that organisms of the Prasynophyceae class may be dominant during autumn, including a member of clade VII, a new taxonomic group recently described. Organisms of the Stramenopiles, Dinophyceae, and Dictyochophyceae groups have been identified from spring samples. Diversity indices (Shannon and Simpson) and dendrograms (based on Euclidean distances) from DGGE and RFLP techniques revealed the annual diversity of the picoeukaryote assemblages.