Practice question

Corona radiata consists of cumulus granulosa cells embedded in hyaluronic acid-rich extracellular matrix surrounding ovulated oocyte. Sperm must disperse this layer before contacting zona pellucida. Acrosomal membrane associated hyaluronidase hydrolyzes beta-1,4 linkages of hyaluronan polymers, breaking intercellular cement and creating paths for motile sperm. This action is complemented by flagellar thrust and other proteases. Hyaluronidase activity is greatly enhanced after capacitation and is localized on sperm surface, allowing efficient penetration of cumulus oophorus without damaging oocyte, facilitating species-specific approach to zona glycoproteins.