sábado, 25 de abril de 2015

Rosa Baeza defiende su Tesis Doctoral

Ayer, 25 de abril, Rosa Baeza alcanzó el grado de Doctora tras defender su Tesis Doctoral titulada: “Overview of lipid roles in male European eel (Anguilla anguilla) reproduction. Application in broodstock diets’, supervisada por mí y financiada fundamentalmente por el Proyecto PRO-EEL.

El tribunal estuvo formado por el Dr. Juan Carlos Navarro (como Presidente) del Instituto de Acuicultura de Torre de la Sal (CSIC, Castellón), el Dr. Eduardo Almansa del Instituto Español de Oceanografía (Tenerife) y el Dr. Óscar Monroig de la University of Stirling (Reino Unido), que tras la exposición y la posterior discusión le concedieron la máxima nota posible: Sobresaliente Cum laude.

El documento final es un compendio de 4 artículos previamente publicados (2 en Aquaculture y 2 en Comparative Biochemistry and Physiology, Part A), con una introducción y una discusión general, y si me lo pedís por e-mail, podemos enviaros un pdf con el texto completo.


Enhorabuena Dra. Baeza!


Resumen
During the last 25 years, eel populations have declined considerably, this species is considered outside safe biological limits. The life cycle of the eel is quite complex including transoceanic migration whose conditions are still so unknown that even the natural spawning process has never been observed.

Eels cease feeding during migration and that is why their energy reserves such as lipids play a crucial role and thus their in deep study is essential to obtain gametes (eggs and sperm) quality as the first step for their reproduction in captivity. In the last years, many efforts have been directed at the study of the influence of fatty acids on the reproductive performance in females, but not in male eels.

The present manuscript describes the results obtained in two experiments. The first experiment (which led to the three first articles included in the memory) focused on the effect of fatty acids along maturation, their relationship with steroid hormones and their effect on sperm quality parameters. The second experiment involved the comparison of different diets designed, considering the previously acquired insights into the most influential fatty acids on male eel reproduction, and the assessment of their influence on the reproductive performance of males.

The first experiment was used to assess the changes in the fat content, as well as fatty acids, in different tissues of male eels hormonally induced to sexual maturation under different thermal regimes (two variables and one constant). Males finished spermatogenesis earlier with a constant temperature of 20 ºC, suggesting that eel spermatogenesis is tightly regulated by temperature. The fat content did not change significantly in the muscle, but was increased in the liver and decreased in testes during testicular development. With regard to fatty acids, during sperm maturation, the liver was highlighted as the main site of synthesis. Finally, EPA, ARA and DHA remained constant in testes, while the level of the rest of fatty acids decreased significantly.

Using samples from the same experiment, the correlation between the main steroid hormones and fatty acids at different stages of testicular development were investigated. Similarly as occurs in mammals, EPA and DHA were highlighted as possible modulators of androgen synthesis. The set of the results obtained suggests new perspectives concerning the functions and interactions between fatty acids and steroids in fish spermatogenesis.

Also, with samples from the first experiment, a study was carried out seeking to establish the possible correlations between different fatty acids and several sperm quality parameters. Correlations between several highly unsaturated fatty acids with parameters such as volume, the percentage of motile sperm and sperm velocity were found.

Finally, with the acquired knowledge so far, a second experiment was carried out designing feeds with different fatty acid percentages in order to evaluate the influence of the diets on sperm quality. The results showed that high levels of DHA and EPA in the diets induce higher volumes and high sperm motility. This study allowed obtaining results applicable to the design of optimum broodstock diets for this species.

martes, 7 de abril de 2015

Rossella Caccia inicia su estancia Erasmus

A principios de marzo se incorporó a nuestro grupo Rossella Caccia, Licenciada en Biología por la Seconda Università di Napoli (Italia) y estudiante de primer año del Máster en Biología marina de la Universitá Politecnica delle Marche (Ancona, Italia).
Ella ha obtenido una beca del programa Erasmus que le permitirá pasar cuatro meses con nosotros.
Está colaborando con nosotros en distintos experimentos, participando en el cuidado de los peces y en los muestreos que vamos realizando, y ya empieza a participar también en distintos análisis de muestras en el laboratorio. Gracias Rossella!

miércoles, 1 de abril de 2015

La 4th AQUAGAMETE Training School realizada con éxito


En el marco de las actividades de la Acción COST AQUAGAMETE (aquagamete.webs.upv.es/web) del 16 al 20 de marzo se ha realizado en la Faculty of Fisheries and Quality of Waters (Vodnany, República Checa) la 4th AQUAGAMETE Training School, titulada: “Optical Microscopy and Image Analysis”

La Training School fue organizada por los Drs. Jacky Cosson y Martin Psenicka. En ella participaron 18 jóvenes investigadores de 9 países diferentes. Doce expertos impartieron las lecciones teóricas y las sesiones prácticas.

La sesiones teóricas fueron:
-"The principles of Optical Microscopy and of Image Analysis" - C. Matthews and C. Rouvière
-"Principles of image build-up in the microscope" - Pr D. Stys on the. 
-"Application of fluorescence and confocal microscopy to aquatic eggs" - Dr G. Prulières
-"Modelisation and quantitative predictions of cell behavior, especially spermatozoa" - Dr H. Gadêlha
-"Analysis of cell interior - 3D reconstruction" - Dr R. Rychtarikova
-"Presentation of CASA (sperm motility parameters) and cell morphometry softwares" - Pr C. Soler Vázquez
-"The use of software dedicated to follow-up of microscope images" - T. Nahlik
-"Cryo-Electron Microscope Tomography" - J. Nebesarova

Y las sesiones prácticas fueron:
-"Setting up the microscope, alignment, observations using different optical techniques"
-"Confocal microscopy",
-"Sperm motility (CASA)"
-"Fixation and immuno-staining on fixed oocytes"
-"Immuno-staining and mounting of eggs"
-"Quantitative cell behavior modelisation"

También se organizaron reunions infomales sobre el uso de software  ImageJ software, de sus  Plug-ins, y de prácticas con Mathlab.
Durante el primer día, antes del inicio de las lecciones, los estudiantes participantes hicieron unas presentaciones cortas para presentarse, hablar sobre sus áreas de investigación y su interés en la temática del curso.
El último día los participantes contestaron una encuesta de satisfacción sobre el nivel general de la actividad y la docencia recibida. La calidad de la training school fue valorada como excelente/muy buena considerando el balance entre sus expectativas y lo llevado a cabo.

Enhorabuena a nuestros colegas de Vodnany y gracias a todos los colaboradores en esta actividad.