Zinc ion flux during mammalian sperm capacitation

• Published in: Nature communications 2018-05, Vol.9 (1), p.2061-10, Article 2061
• Main Authors: Kerns, Karl, Zigo, Michal, Drobnis, Erma Z., Sutovsky, Miriam, Sutovsky, Peter
• Format: Article
• Language: English
• Subjects: 14/34; 49/31; 631/80; 631/80/2373; Animals; Artificial insemination; Bicarbonates; Calcium influx; Calcium ions; Capacitation; Cations, Divalent - metabolism; Chelating agents; Chelating Agents - pharmacology; Chlorides - pharmacology; Flow cytometry; Flow Cytometry - methods; Humanities and Social Sciences; In vitro fertilization; Ion distribution; Ion flux; Male; Mammals; multidisciplinary; Phosphorylation; Proteasomes; Proteins; Regulatory mechanisms (biology); Reproduction (biology); Science; Science (multidisciplinary); Semen; Semen Analysis; Sperm; Sperm Capacitation - drug effects; Sperm Capacitation - physiology; Spermatozoa; Spermatozoa - metabolism; Swine; Tyrosine; Zinc; Zinc - metabolism; Zinc chloride; Zinc Compounds - pharmacology
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-04523-y

Sperm capacitation, the ultimate maturation event preparing mammalian spermatozoa for fertilization, was first described in 1951, yet its regulatory mechanisms remain poorly understood. The capacitation process encompasses an influx of bicarbonate and calcium ions, removal of decapacitating factors, changes of pH and sperm proteasomal activities, and the increased protein tyrosine phosphorylation. Here, we document a novel biological phenomenon of a unique zinc (Zn 2+ ) ion redistribution associated with mammalian sperm in vitro capacitation (IVC). Using image-based flow cytometry (IBFC), we identified four distinct types of sperm zinc ion distribution patterns (further zinc signature) and their changes during IVC. The zinc signature was altered after sperm capacitation, reduced by proteasomal inhibitors, removed by zinc chelators, and maintained with addition of external ZnCl 2 . These findings represent a fundamental shift in the understanding of mammalian fertilization, paving the way for improved semen analysis, in vitro fertilization (IVF), and artificial insemination (AI). During sperm capacitation physiological changes occur that are required for fertilization. Here, the authors describe four sperm zinc signatures during invitro capacitation that are indicative of sperm quality and capacity to fertilize.