Nuestro último artículo, publicado en Aquaculture

Ionic control of sperm motility and trials for the improvement of pufferfish (Takifugu alboplumbeus) sperm extenders

L. Pérez, J.F. Asturiano, M. Yoshida, V. Gallego

Abstract: Seminal plasma characteristics, such as ionic composition and pH, are important for sperm maturation and further motility. In this work, a first batch of experiments evaluated the effect of the absence of several ions (Na⁺, K⁺, Mg²⁺) in the artificial seminal plasma, as well as the effect of artificial seminal plasma pH and seawater pH, on the sperm activation in the pufferfish (Takifugu alboplumbeus, named before T. niphobles). In all the experiments, total motility, progressive motility, curvilinear velocity, straight line velocity, and average path velocity were measured. The absence of Na⁺, K⁺ or Mg²⁺ ions did not reduce the sperm motility in comparison with the control. In contrast, artificial seminal plasma pH had a strong effect on sperm motility. Samples diluted in artificial seminal plasma at pH 6.5 showed a high reduction of sperm motility in comparison with higher pHs (7.5, 8.5 and 9.5), and this inhibition was reversible. Where the effect of the pH of artificial seawater in sperm motility (used as activation medium) was concerned, there were no significant differences between the control (pH 8.2) and pH 6.5, indicating that pufferfish spermatozoa can swim in acidic environments. Finally, nigericin (that make equal the intracellular pH and extracellular pH) was added, and the highest sperm motility was found at pH 7.0, which suggested that the optimal intracellular pH of pufferfish for sperm motility is 7.0.

Our second batch of experiments was developed to optimize the pufferfish sperm extenders to achieve longer preservation under refrigeration, assessing the addition of several concentrations of magnesium and NaHCO₃ (used in extenders for other fish species), as well as different pHs. From the extender experiments it was observed that bicarbonate reduced the sperm motility after 7 days of incubation, and it can be concluded that the use of magnesium 2 mM as part of the extender composition, in combination with the pH measured in the pufferfish sperm (7.5), seems to be the best option for the short-medium term storage of the sperm of this species.

Aquaculture 554,738146

doi: 10.1016/j.aquaculture.2022.738146

Wendy González se incorpora al equipo

Wendy González es originaria de México, donde realizó sus estudios de Licenciatura en Biología por el Instituto Tecnológico de Chetumal y maestría en Biología Marina por el Centro de Investigación y de Estudios Avanzados (CINVESTAV, Unidad Mérida). Además, realizó estudios de doctorado en acuicultura por la Universidad Autónoma de Barcelona, realizando su proyecto de investigación en las instalaciones del Institut de Recerca y Tecnologia Agroalimentariès (Sant Carles de la Rápita, Tarragona), en aspectos del estudio del comportamiento reproductivo y alternativas para la reproducción del lenguado senegalés (Solea senegalensis).

Actualmente cuenta con un contrato posdoctoral del Programa “Margarita Salas” para trabajar con nuestro grupo de investigación
en temas relacionados con el efecto del cambio climático sobre la fisiología espermática, la criopreservación de gametos y la evaluación de calidad seminal de peces de diferentes especies de interés para el sector de la acuicultura.

Nuestro último artículo, publicado en Marine Pollution Bulletin

Ex vivo exposure to titanium dioxide and silver nanoparticles mildly affect sperm of gilthead seabream (Sparus aurata) - a multiparameter spermiotoxicity approach

A. Carvalhais, I.B. Oliveira, H. Oliveira, C.C.V. Oliveira, L. Ferrão, E. Cabrita, J.F. Asturiano, S. Guilherme, M. Pacheco, C.L. Mieiro

Abstract: Nanoparticles (NP) are potentially reprotoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO2: 10 to 10,000 μg/L) and silver NP (Ag: 0.25 to 250 μg/L) on the sperm of gilthead seabream (Sparus aurata). We performed short-term direct exposures (ex vivo) and evaluated sperm motility, head morphometry, mitochondrial function, antioxidant responses and DNA integrity. No alteration in sperm motility (except for supra environmental Ag NP concentration), head morphometry, mitochondrial function, and DNA integrity occurred. However, depletion of all antioxidants occurred after exposure to TiO2 NP, whereas SOD decreased after exposure to Ag NP (lowest and intermediate concentration). Considering our results, the decrease in antioxidants did not indicate vulnerability towards oxidative stress. TiO2 NP and Ag NP induced low spermiotoxicity, without proven relevant ecological impacts.

doi: 10.1016/j.marpolbul.2022.113487