IIBYT   23944
INSTITUTO DE INVESTIGACIONES BIOLOGICAS Y TECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Variability of human sperm samples along the incubation time and seasons
Autor/es:
MORENO A; GUIDOBALDI HA; GIOJALAS LC; GALLEA MN; TREVIÑO C; DOMINGUEZ EM; MATAMOROS A
Lugar:
Holderness School, Holderness, NH.
Reunión:
Congreso; Gordon Research Conference on Fertilization and Activation of Development; 2017
Institución organizadora:
Gordon Research Conference
Resumen:
In mammals, the spermatozoon must be physiologically prepared to fertilize the egg. That preparation is called ?sperm capacitation?. Human sperm samples are extremely variable in terms of the ability to capacitate themselves. Such variation is observed not only between different sperm donors but also between different samples from the same donor. We hypothesize that sperm capacitation vary not only along incubation time but also along the seasons. To test this hypothesis sperm capacitation was evaluated by means of the induced A23187 acrosome reaction, the level of protein phosphorylation in tyrosine, and the ability of capacitated spermatozoa to be recruited by chemotaxis towards progesterone. Human sperm samples were separated from seminal plasma by the migration-sedimentation technique. Then, for daily variation, spermatozoa were incubated under capacitating conditions for 24 h, determining the level of sperm capacitation every hour. The level of capacitation increased with fluctuations along time, whereas 100% of the samples poorly capacitate after 2 hours, in contrast with the 100% of samples that capacitate after 18 h of incubation. Then, sperm capacitation was evaluated in the middle of each month (at 4 and 18 hours of incubation under capacitating conditions), during 3-4 consecutive years (2014 to 2017). A significant decrease in sperm capacitation was observed in winter time, followed by and abrupt recovery in July-August. This sperm variation along the year is correlated with monthly temperature, photoperiod and radiation. We conclude that the best time to perform experiments with human sperm samples is late winter until early summer, and incubating the samples for 18 hours.