G. S. Yasui1†, J. A. Senhorini2, E. Shimoda3, M. Pereira-Santos4, L. S. O. Nakaghi4, T. Fujimoto5, L. Arias-Rodriguez6 and L. A. Silva1 1Laboratory of Theriogenology Dr. O. J. Ginther, Department of Veterinary Medicine – FZEA, University of Sao Paulo, Avenida Duque de Caxias Norte 225, Pirassununga, SP 13630-080, Brazil; 2National Center for Research and Conservation of Continental Fish, Chico Mendes Institute of Biodiversity Conservation, Rodovia Pref. Euberto Nemésio Pereira de Godoy, Pirassununga, SP 13630-970, Brazil; 3Department of Pharmacy, Cândido Mendes University, Rua Anita Peçanha 100, Campos dos Goytacazes , RJ 28030-335, Brazil; 4Aquaculture Center, Sao Paulo State University, Via de Acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, SP 14884-900, Brazil; 5Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, 041-8611, Hakodate, Japan; 6Biological Sciences Academic Division,
Juarez Autonomous University of Tabasco, C.P. 86150 Villahermosa, Tabasco, México |
In fish, in vitro fertilization is an important reproductive tool used as first step for application of others biotechniques as chromosome and embryo manipulation. In this study, we aimed to optimize gamete quality and their short-term storage from the yellowtail tetra Astyanax altiparanae, for future application in laboratory studies. Working with sperm, we evaluated the effects of spawning inducers (carp pituitary gland and Ovopel® [(D-Ala6, Pro9-NEt) – mGnRH+metoclopramide]) and the presence of female on sperm motility. Additionally, we developed new procedures for short-term storage of sperm and oocytes. Briefly, sperm motility was higher when male fish were treated with carp pituitary gland (73.1 ± 4.0%) or Ovopel® (79.5 ± 5.5%) when compared with the control group treated with 0.9% NaCl (55.6 ± 27.2%; P = 0.1598). Maintenance of male fish with an ovulating female fish also improved sperm motility (74.4 ± 7.4%) when compared with untreated male fish (42.1 ± 26.1%; P = 0.0018). Storage of sperm was optimized in modified Ringer solution, in which the sperm was kept motile for 18 days at 2.5°C. The addition of antibiotics or oxygen decreased sperm motility, but partial change of supernatant and the combination of those conditions improve storage ability of sperm. Fertilization ability of oocytes decreased significantly after storage for 30, 60 90 and 120 min at 5, 10, 15 and 20°C when compared with fresh oocytes (P = 0.0471), but considering only the stored samples, the optimum temperature was 15°C. Those data describe new approaches to improve semen quality and gametes short-term storage in yellowtail tetra A. altiparanae and open new possibilities in vitro fertilization. |