Morfología y filogenia del rDNA de una subespecie mediterránea de Coolia Monotis (Dinophyceae) de Grecia

Sequences of LSU and SSU ribosomal RNA genes and phylogeny have not been widely investigated for the dinoflagellate Coolia monotis Meunier, and no information is available on the small and large rDNA subunits of Mediterranean strains. A strain isolated from the Thermaikos Gulf in northern Greece was identified as C. monotis—a new record for the Greek algal flora—using thecal morphology by light, epifluorescence and scanning electron microscopy. The small subunit and partial (D1/D2) large subunit sequences were analyzed and compared to other strains of C. monotis and dinoflagellates from various regions. Thecal architecture showed that the Greek strain of C. monotis was phenotypically similar, but not identical, to other strains reported in literature. The partial LSU sequence (700 bp) was found to vary by 113 bp positions (16%) from the C. monotis strain from New Zealand, whereas the SSU (1757 bp) had 15 bp differences (0.85%) from the strain from Norway. Phylogenetic tree construction showed that the Greek strain fell within the Coolia clade and had a close relationship with the families Ostreopsidaceae and Goniodomaceae of the order Gonyaulacales. Preliminary findings suggest the existence of different genotype strains of C. monotis with large intraspecific genetic variability and minimal morphological differentiation (similar phenotypes). Certain ecological and evolutionary implications of these findings are discussed.Las secuencias de los genes del RNA de las subunidades ribosomales grandes y pequeñas (LSU y SSU, respectivamente) y la filogenia del dinoflagelado Coolia monotis Meunier han sido poco investigadas, y no hay información disponible sobre los genes LSU y SSU de subespecies mediterráneas. Una subespecie aislada del golfo de Thermaikos en el norte de Grecia fue identificada como C. monotis –una nueva aportación a la flora algal griega– por medio de la morfología de la teca observada a través de microscopía óptica, de epifluorescia y electrónica. Las secuencias correspondientes a la subunidad pequeña y a la parte (D1/D2) de la subunidad grande fueron analizadas y comparadas a las de otras subespecies de C. monotis y otras especies de dinoflagelados de diversas regiones. La arquitectura de la teca mostró que la subespecie griega de C. monotis era fenotípicamente similar, pero no idéntica, a otras subespecies registradas en la literatura. Se encontró que la secuencia parcial de la LSU (700 pares de bases o bp) difería de la de C. monotis de Nueva Zelanda en las posiciones de 113 bp (16%), mientras que la SSU (1757 bp) se diferenciaba en 15 bp (0.85%) de la subespecie de Noruega. La construcción del árbol filogenetico demostró que la subespecie griega se situaba dentro de la rama de Coolia y presentaba una relación cercana con las familias Ostreopsidaceae y Goniodomaceae del orden Gonyaulacales. Resultados preliminares sugieren la existencia de diversos genotipos de la subespecie de C. monotis con una importante variabilidad genética intraespecífica y una mínima diferenciación morfológica (fenotipos similares). Se comentan diversas implicaciones ecológicas y evolutivas de estos resultados

Efficiency of Manual Scanning in Recovering Rare Cellular Events Identified by Fluorescence In Situ Hybridization: Simulation of the Detection of Fetal Cells in Maternal Blood

Fluorescence in situ hybridization (FISH) and manual scanning is a widely used strategy for retrieving rare cellular events such as fetal cells in maternal blood. In order to determine the efficiency of these techniques in detection of rare cells, slides of XX cells with predefined numbers (1–10) of XY cells were prepared. Following FISH hybridization, the slides were scanned blindly for the presence of XY cells by different observers. The average detection efficiency was 84% (125/148). Evaluation of probe hybridization in the missed events showed that 9% (2/23) were not hybridized, 17% (4/23) were poorly hybridized, while the hybridization was adequate for the remaining 74% (17/23). In conclusion, manual scanning is a relatively efficient method to recover rare cellular events, but about 16% of the events are missed; therefore, the number of fetal cells per unit volume of maternal blood has probably been underestimated when using manual scanning