Fertilization Flashcards
when is the best window for insemination?
6 hours after ovulation
can you inseminate prior tot he six hour window? after?
can inseminate before with lower chances of success but probably not after because ovulation will be finished
what scenario do you want in terms of sperm and the oocyte for insemination?
almost always want sperm waiting on the oocyte, not the other way around
define capacitation
the changes within sperm that confer upon the sperm the ability to acrosome react to the appropriate stimulus
what is the appropriate stimulus that causes sperm to acrosome react?
proximity to oocyte
describe the state of capacitation in mammalian sperm in the epidiymis
plasma membrane of epidydimal spermatozoa contains a complement of surface molecules that will combine with seminal plasma
describe the state of capacitation in mammalian sperm once ejaculated
the surace molecules in epidydimal sperm become coated with seminal plasma proteins that mask portions of the membrane molecules, DECAPACITATED
describe the state of capacitation on mammalian sperm when exposed to the female tract
when exposed to the female tract environment, the seminal plasma coatings and some of the surface molecules are moved, exposing portions of the molecules that can bind to the zona pellucida, CAPACITATED
is there change in sperm morphology in capacitation?
no, capacitated sperm will look the same as not capacitated sperm under a microscope
what characteristic of sperm changes during capacitation?
motility
describe the motility change in sperm during capacitation
hyperactivation: quick zig zags yield more power output from the tail, making the sperm more likey to interact with the oocyte
list the 6 steps in the sequence of events of fertilization
- sperm capacitation and hyperactive motility
- sperm BINDING to zona pellucida
- sperm acrosome react
- sperm get through zona pellucida
- sperm FUSE with oolema
- sperm enters oocyte
what 3 events occur once the sperm enters the oocyte in fertilization?
- resumption of meiosis II by oocyte
- sperm nucleus decondenses
- formation of two pronuclei (1M and 1F)
what determines how many zona pellucida proteins (ZP) exist and their function?
species variations
what is the general function of ZP 1 and ZP2?
maintain zona pellucida structure