Mouse sperm lacking SLO3 channels bend their flagellum after incubation under capacitating conditions

GÓMEZ-OLIVIERI LUCILA; BALESTRINI, PAULA A.; SANTI CELIA; MARIN BRIGGILER, CI; LUQUE GM; BUFFONE MG

Congreso; Reunion SAIC; 2022

Sociedad Argentina de Investigacion Clinica

152) SPERM LACKING SLO3 CHANNELS BEND THEIRFLAGELLUM AFTER INCUBATION UNDER CAPACITATINGCONDITIONSLucila Gomez Olivieri1, Paula A. Balestrini1, Celia Santi2,Clara I. Marin Briggiler1, Guillermina M. Luque1, Mariano G.Buffone1.1Instituto de Biología y Medicina Experimental (IBYME), ConsejoNacional de Investigaciones Científicas y Técnicas (CONICET),Buenos Aires, Argentina.2 Department of obstetrics and Gynecology, Washington University,St Louis, MO. USA.During capacitation, where sperm acquire the ability to fertilize theegg, the gametes undergo a hyperpolarization of the plasma membranepotential (Em). This change in their Em is essential for theoccurrence of acrosomal exocytosis and in mice, is mainly drivenby the sperm-specific K+ channel SLO3. In this work, by using SLO3KO sperm, we found that once cells are incubated under capacitatingconditions, a fraction of them (~50%, vs WT, p < 0.05) display abending of the flagellum called hairpin. In time course experiments,we observed that this increase occurs very rapidly (within the first 15min of incubation). Moreover, the hairpin rise in SLO3 KO mice wasalso observed in sperm obtained from the female uterus after mating.To evaluate how Em could be altering sperm morphology, SLO3KO sperm were incubated in conditions that pharmacologically promoteEm hyperpolarization: valinomycin (K+ ionophore), amiloride(Na+ channel inhibitor), ouabain (active Na,K-ATPase inhibitor), andgenistein (CFTR voltage-dependent channel inhibitor). Only theaddition of valinomycin significantly decreased the percentage ofSLO3 KO sperm with hairpin (p < 0.05). In addition, SLO3 WT spermwere incubated in a high K+ concentration medium to keep the Emdepolarized. However, in this condition, sperm did not develop thischange in morphology. In conclusion, sperm from SLO3 KO mice invitro and in vivo develop flagellar abnormalities during capacitationthat are not fully explained by the alteration on Em.