Role of calcium on the initiation of sperm motility in the European eel

• Published in: Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology
• Main Authors: Pérez Igualada, Luz María, Vilchez Olivencia, Maria Carmen, Gallego Albiach, Victor, MORINI, MARINA, Peñaranda, D.S., Asturiano Nemesio, Juan Francisco
• Other Authors: Universitat Politècnica de València. Instituto de Ciencia y Tecnología Animal - Institut de Ciència i Tecnologia Animal, Universitat Politècnica de València. Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural - Escola Tècnica Superior d'Enginyeria Agronòmica i del Medi Natural, Ministerio de Ciencia e Innovación
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2016
• Subjects: envir; hist; European eel
• Online Access: https://doi.org/10.1016/j.cbpa.2015.10.009; http://hdl.handle.net/10251/79931; http://dx.doi.org/ 10.1016/j.cbpa.2015.10.009

S [EN] Sperm from European eel males treated with hCG(rec), was washed in a calcium free extender, and sperm motility was activated both in the presence (seawater, SW) and in the absence of calcium (NaCI + EDTA), and treated with calcium inhibitors or modulators. The sperm motility parameters were evaluated by a computer-assisted sperm analysis (CASA) system, and changes in the [Ca2+](i) fluorescence (and in [Na+](i) in some cases) were evaluated by flow cytometry. After sperm motility was activated in a medium containing Ca2+ (seawater, SW) the intracellular fluorescence emitted by Ca2+ increased 4-6-fold compared to the levels in quiescent sperm. However, while sperm activation in a Ca-free media (NaCI + EDTA) resulted in a percentage of motility similar to seawater, the [Ca2+](i) levels did not increase at all. This result strongly suggests that increasing [Ca2+](i) is not a pre-requisite for the induction of sperm motility in European eel sperm. Several sperm velocities (VCL, VSL, VAP) decreased when sperm was activated in the Ca-free activator, thus supporting the theory that Ca2+ has a modulatory effect on sperm motility. The results indicate that a calcium/sodium exchanger (NCX) which is inhibited by bepridil and a calcium calmodulin kinase (inhibited by W-7), are involved in the sperm motility of the European eel. Our results indicate that the increase in [Ca2+](i) concentrations during sperm activation is due to an influx from the external medium, but, unlike in most other species, it does not appear to be necessary for the activation of motility in European eel sperm. (c) 2015 Elsevier Inc All rights reserved. Funded from the SPERMOT project (Spanish Ministry of Science and Innovation, MICINN; AGL2010-16009). M.C. Vilchez has a predoctoral grant from UPV PAID Program (2011-S2-02-6521), Marina Morini has a predoctoral grant from Generalitat Valenciana (Programa Grisolia, GRISOLIA/2012/006), Victor Gallego has a postdoctoral contract from UPV (PAID-10-14), and David S. Penaranda was supported by MICINN ...