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The oolemma in polyspermy block
Fusion of sperm‐oocyte plasma membranes requirement for establishment of the plasma membrane block to polyspermy.
Block absent in ICSI or parthenogenetic activation Mechanism independent of cortical reaction Mouse oocytes (Maleszewski et al 1996) Human oocytes (Sengoku et al 1999) Mechanism unspecified at the time.
Juno is the Izumo receptor on oocytes
Fertilisation requires fusion of egg‐sperm membrane
Two receptor proteins implicated in the recognition and/or fusion process, and affect fertility:
Sperm: Izumo1 (Inoue et al. 2005) (named after a Japanese marriage shrine)
Oocyte: Folate receptor 4 (Folr4), a GPI‐anchored protein expressed on the egg surface, aka “Juno”
(Bianchi et al. 2014)
(named after the Roman goddess of fertility and marriage)
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PRECONGRESS COURSE 02 I VIENNA, AUSTRIA – 23 JUNE 2019 33