Spermatozoa in the Female Tract (Ch 12)
deposition of sperm
in cranial vagina
cow, sheep, rabbit, primates, dogs, cat
directly into the cervix
pigs, horses, camelids
through the cervical lumen
horse
after ejaculation, many spermatozoa are lost from the female tract
phagocytosis
neutrophils attack the foreign sperm
retrograde transport
cervix is a major barrier
contains mucus
sialomucin
sulfomucin
low viscosity
high viscosity
sperm that encounter this mucus are washed out
found in the deeper cervical crypts and is known as the privileged pathway
sperm that encounter this mucus have a much high chance of getting higher into the female tract
capacitation
sperm must be in the female tract for a certain period of time before gaining full fertility
sperm are stripped of coating proteins that allow them to be able to penetrate the zona pellucida
initiated in the uterus
completed in the oviduct
once completely capacitated, sperm will undergo hyperactivity
facilitates sperm-oocyte contact
fertilization
sperm binds to zona pellucida at the primary zona binding region
second binding site is the acrosome reaction promoting ligand
triggers acrosomal reaction that enables the sperm to penetrate the ZP and modidies the equatorial segment to later fuse with the plasma membrane of the oocyte
vesiculation
penetrate ZP
sperm and oocyte fuse
sperm is engulfed
sperm nucleus decondenses
male pronucleus forms
allows male and female DNA to form a single nucleus
