Lec.5 FERTILIZATION Flashcards
-is the process by which the
spermatozoon and the egg unite.
-union of the male and female pronuclei.
Fertilization
duration of copulation in
ruminants -
horses -
pigs -
dogs -
ruminants - less than a minute
horses - few minutes longer
pigs - several minutes
dogs - 5-30 minutes
act of mating.
copulation
What animals have the semen deposited in the vagina?
cows, sheep, rabbit, dog, cat, primates
what animals have the semen ejaculated directly into the cervix and/or the uterus.
pigs, horses, camelids
what is the volume of sperm in ruminants (concentrated with spermatozoa)
3-4 mL
what is the volume of sperm in boar (low concentration of spermatozoa)
200-400 mL
what is the animal that ejaculates in a series of ‘jets’, of which the first usually contains the fraction rich in spermatozoa.
Stallion
what is the volume of sperm in dogs
1-85 mL
what is the volume of sperm in cats
0.2-0.3 mL
Retrograde loss of spermatozoa from the
female genital tract depends on:
the volume
the physical nature of the ejaculate
the site of its deposition within the female genital tract
what animal releases thick coagulum in their last ejaculation to act as ‘plugs’, preventing backflow of semen.
pigs
Spermatozoa are not able to fertilize the oocyte immediately after arrival in the female genital tract, they need to ____ themselves first.
Biochemical changes will occur in the sperm, and this usually occurs in the uterus / cervix.
capacitate
this surrounds the oocyte and is critically involved in fertilization: such as
the adhesion and binding of capacitated spermatozoa
the induction of the acrosome reaction and penetration
the fertilization-induced modifications that prevent polyspermy
zona pellucida
The zona pellucida has species- specific receptors for spermatozoa.
Sperm that comes in contact with ZP will undergo ____.
firm binding
Once bound, the sperm will release hydrolytic enzymes (acrosin and hyaluronidase) from its acrosome.
This will allow the sperm to penetrate the ZP in combination with the propulsive movement of its tail.
Acrosome reaction
*Fusion of the gametocytes
After penetration of the ZP, sperm adhere to and fuse with the plasma membrane of the oocyte.
The fertilizing spermatozoon will be engulfed by the oocyte.
This process is referred to as?
syngamy / fertilization
Once a sperm has entered, the cortical granules from the oocyte will stimulate the modification of the oocyte membrane and the ZP.
This will induce ____, which won’t allow entry of any other sperm.
zona block
Once Oocyte activation happens, meiosis will resume in the oocyte, creating a ____.
The tail of the spermatozoon detaches and degenerates.
second polar body and a zygote
