Ionic regulation of sterlet (<em>Acipenser ruthenus</em>) spermatozoa <em>in vitro</em> maturation — ASN Events
  1. Schedule
  2. Session 6.2: Acquisition and loss of sperm function
  3. Ionic regulation of sterlet (Acipenser ruthenus) spermatozoa in vitro maturation

Ionic regulation of sterlet (Acipenser ruthenus) spermatozoa in vitro maturation (#45)

Olga Bondarenko 1 , Borys Dzyuba 1 , Jacky Cosson 1 , Galina Prokopchuk 1 , Sergii Boryshpolets 1 , Viktoriya Dzuyba 1 2 , Marek Rodina 1 , Otomar Linhart 1
  1. South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Faculty of Fisheries and Protection of Waters, University of South Bohemia in Ceske Budejovice, Vodnany, Czech Republic
  2. Institute of Biology, V.N. Karazin Kharkiv National University, Kharkiv, Ukraine

During the sturgeon sperm maturation testicular sperm is diluted with hypotonic urine (Krayushkina et al., 2006) during passing through kidney to mesonephric (Wolffian) ducts where the last stage of maturation occurs (Dzyuba et al., 2014). However, the role of ions alteration as a result of testicular sperm mixture with urine in sperm maturation is not fully investigated. Thus, the aim of this study was to explore the role of Ca2+ ions in the in vitro sturgeon sperm maturation.

For this purpose, testicular (immature) sperm was collected from 6 sterlet males (Acipenser ruthenus) via incision of the efferent ducts before their entering to the kidney.  Procedure of sperm in vitro maturation was run according to Dzyuba et al., 2014. For maturation, testicular sperm was incubated for 5 min at 20°C in the seminal fluid of naturally matured sperm, collected from Wolffian ducts.  Motility was evaluated by using video microscopy. To investigate the role of Ca2+ dynamics during in vitro sperm maturation 2mM EGTA (exocellular Ca2+ chelating agent) or 100µM verapamil or tetracaine (blockers of Ca2+ channel) were added to seminal fluid during incubation.

Testicular sperm were immotile in all studied media. However, in vitro maturation leads to motility activation appearance.  The presence EGTA or calcium channel blockers prevent sperm maturation. Thus, we propose calcium as a main participant in the last stages of sturgeon’s sperm maturation.

To determine the precise mechanisms of Ca2+ action during sturgeons sperm maturation future studies are required.

ACKNOWLEDGEMENTS

Special thanks are expressed to the projects: IAA 608030801, ME10015, QH82119, LC06073, CZ.1.05/2.1.00/01.0024, GACR P502/11/0090, GAJU 046/2010/Z., GAJU 123/2014/Z 2014.

  1. Krayushkina L.S., Semenova O.G. 2006: Osmotic and ion regulation in different species of Acipenserids (Acipenseriformes, Acipenseridae). J Ichthyol 46, 108-19.
  2. Dzyuba B., Cosson J., Boryshpolets S., Bondarenko O., Dzyuba V., Prokopchuk G., Gazo I., Rodina M., Linhart O. 2014. In vitro sperm maturation in sterlet, Acipenser ruthenus. Reprod Biol, 14(2):160-3