Sperm physiology varies according to ultradian and infradian rhythms

MORENO-IRUSTA, AYELEN; KEMBRO, JACKELYN M.; DOMINGUEZ, ESTEBAN M.; MATAMOROS-VOLANTE, ARTURO; GALLEA, NOEL; MOLINA, ROSA; GUIDOBALDI, HECTOR A.; TREVIÑO, CLAUDIA L.; FIGUERAS, MARIA J. ; BABINI, ANA; PAINA, NELSO A.; MERCADO, CARLOS A.; GIOJALAS, LAURA C.

Scientific Reports

Springer Nature Publishing AG

Año: 2019

The spermatozoon must be physiologically prepared to fertilize the egg, process called capacitation. Human sperm samples are heterogeneous in their ability to capacitate themselves, which leads to variability between samples from the same or different donors. Here we studied sperm heterogeneity by means of the sperm capacitation, according to the ability of capacitated spermatozoa to acrosome react upon stimulation and to be recruited by chemotaxis. Both indicators of sperm capacitation showed fluctuations and increased along the incubation time. Those capacitated sperm recruited by chemotaxis showed an ultradian rhythm of about 2 hours which might be influenced by unknown intrinsic sperm factors. Moreover, the observed sperm heterogeneity may also be due to seasonal changes. Thus, a circannual rhythm, and in part a 6 months one, were observed, which are modulated by the joint action of temperature and photoperiod. As whole, sperm physiology varies according to an ultradian an circannual rhythm, innovative vision of sperm physiology that may contribute to a better comprehension of mammalian reproductive biology.