Cambios estacionales en la calidad seminal de neomachos de trucha arcoiris (Oncorhynchus mykiss)Integridad de la cromatina

Resumen

The use of good quality gametes is of outmost importance in aquaculture. Commercial farming of rainbow trout (Oncorhynchus mykiss) is frequently based on the use of sex reverted females (neomales) as breeders, kept under artificial photoperiod in order to avoid seasonality. Neomales sperm has a low antioxidant capacity and maturation at different thermal regimes could affect the sperm quality. Our objective was to analyze the seasonal variation on the integrity of plasma membrane and chromatin. Sperm was sampled through a year (December, March, June and September) and cell viability and apoptosis were evaluated by flow citometry using the probes Propidium Iodide (PI) and Yo-PRO1. Chromatin fragmentation was analyzed using the Comet assay and the percentage of cells showing ranges of fragmentation (DNAt) from <5%, 5-15% and >15% where evaluated. Seasonality significantly affects the quality of samples. Sperm from December, at the natural reproductive season, showed more than 90% of viable cells and 85% of cells with non-fragmented chromatin, whereas in June the lower rates of cell viability and the higher rates of chromatin fragmentation where noticed. Data showed us that the quality of samples obtained out of season could compromise their fertilization ability and the success of further embryo development.