jueves, 24 de abril de 2014
Durante cuatro semanas hemos tenido con nosotros a Eszter Kása, que realiza su Tesis Doctoral en la Szent István University (Gödöllő, Hungría) bajo la supervisión de nuestro colega Ákos Horváth. Eszter ha contado con una Short Term Scientific Mission financiada por AQUAGAMETE. Hemos trabajado en distintas técnicas de preservación de esperma de anguila europea, aunque los machos no han colaborado mucho esta vez. Así que Eszter, tendrás que volver!
Los primeros resultados se presentarán en las V Jornadas Ibéricas de Ictiología en Lisboa en junio, y en la sesión especial de AQUAGAMETE en el EAS2014 en San Sebastián en octubre.
domingo, 6 de abril de 2014
Sperm motility parameters and spermatozoa morphometric characterization in marine species: a study of swimmer and sessile species
V. Gallego, L. Pérez, J.F. Asturiano and M. Yoshida
The biodiversity of marine ecosystems is diverse and a high number of species coexist side by side. However, despite the fact that most of these species share a common fertilization strategy, a high variability in terms of the size, shape and motion of spermatozoa can be found. In this study, we have analysed both the sperm motion parameters and the spermatozoa morphometric features of two swimmer (pufferfish and European eel) and two sessile (sea urchin and ascidian) marine species.
The most important difference in the sperm motion parameters was registered in the swimming-time period. The sperm of the sessile species displayed notably higher values than those of the swimmer species. In addition, the sperm motilities and velocities of the swimmer species decreased sharply from the moment the sperm was activated, whereas the sessile species were able to maintain their initial values for a long time. These results are linked directly to the species-specific lifestyles. While sessile organisms, who demonstrate limited or no movement, need to have sperm with a capacity to swim for long distances in order to find the oocytes, swimmer organisms can move towards the female and release gametes near it, and therefore the spermatozoa does not need to be able to swim for such a long time period.
On the other hand, sperm morphology is related to sperm motion parameters and in this study an in depth morphometric analysis by CASA software of ascidian, sea urchin and pufferfish spermatozoa has been carried out for the first time. A huge variability in shapes, sizes, and structures were found using electron microscopy in the studied species.
International Conference on "Sex determination and differentiation in fishes - Genes, environment and behaviour
It will take place September 23th–24th, 2014 at Fundação da Faculdade de Ciências (FFCUL), Lisboa.
This conference aims to promote knowledge exchange and debate on the latest findings regarding processes of sex differentiation and mechanisms of primary sex determination in fishes. Genetic/epigenetic, environmental and behavioural factors will be discussed as well as the diversity of evolutionary scenarios described in fishes.
This international meeting will feature three outstanding speakers in the field: MANFRED SCHARTL (University of Würzburg, Germany), FRANCESC PIFERRER (Institut de Ciencies del Mar, CSIC, Spain) and RUI OLIVEIRA (ISPA, Portugal).