Polyspermy is one of the most commonly observed abnormal types of fertilization in @entity1 oocytes. @entity52 ( @entity52 ) provides approaches to study the mechanisms by which oocytes block polyspermic fertilization. Accumulated data indicate that oocyte, sperm and insemination conditions are all related to the occurrence of polyspermic fertilization. A high proportion of immature and aged oocytes showed polyspermy as compared with mature oocytes. Preincubation of oocytes and/or sperm with oviductal epithelial cells or collected oviductal fluid before @entity52 reduces polyspermic penetration. Recently, it was found that an abnormal zona pellucida is one of main causes of polyspermy in @entity1 eggs. A high proportion of polyspermy has resulted from the use of a high concentration of capacitated spermatozoa at the site of fertilization, irrespective of in the in vivo or in vitro environment. Oviductal secretions or oviductal epithelial cells themselves can regulate the number of spermatozoa reaching or binding to the zona pellucida thus reducing multiple sperm penetration. Suboptimal in vitro conditions, such as supplementations in @entity52 media, pH, and temperature during @entity52 , also induce polyspermic fertilization in some mammals. Species-specific differences are present regarding the relationship between insemination conditions and polyspermy.

How does polyspermy happen in XXXX oocytes?

@entity1 :: ('9606', 'Species') :: ['mammalian', 'human'] @entity52 :: ('MESH:C566179', 'Disease') :: ['In vitro fertilization', 'IVF']
@entity1 :: (9606,Species) :: ['mammalian']
