9B: Fertilization Flashcards
Only 2 animals with site of semen deposition is in UTERUS?
the rest is in VAGINA
- sow
- mare
STAGES of SPERM TRANSPORT
a. Presence of first sperms in oviduct after mating
b. These sperms are not involved with fertilization because of structural damage to them during rapid transport
Initial rapid transport
(mating
→ semen ejaculated
→ released to female reproductive tract)
STAGES of SPERM TRANSPORT
a. Formed 6-12 hrs after semen deposition
b. Slowly transported sperms
establishment of sperm reservoir
(sperms released after initial rapid transport)
Spermatozoa haploid in nature, needs ____ ____ so as not to be recognized as
foreign by female body
sperm reservoir
STAGES of SPERM TRANSPORT
a. Goes to ampulla
b. Sperms can have higher percentage to fertilize ovum or ova
slow release of sperm
(from sperm reservoir to
oviduct)
Only (2) animals with sperm reservoir is location in UTEROTUBAL JUNCTION
the rest is in CERVIX
- sow
- mare
(2) animals with sperm fertilizing capacity is up to 90 hours
- bitch
- queen
(3) animals with sperm fertilizing capacity is up to 24-48 hours
- cow
- ewe
- sow
ONLY animals with sperm fertilizing capacity is up to 5 DAYS
MARE
junction between uterus and fallopian tube
Uterotubal junction
length of time sperm is still viable and can fertilize the ovum
sperm fertilizing capacity
activation of acrosome important for sperm to
penetrate ovum
SPERM CAPACITATION
site of sperm capacitation
uterus to the ➔ isthmus of oviduct
◆ Modification or removal of sperm surface components by oviductal & uterine fluids
◆ Depletion of sperm cholesterol & glycoproteins at sperm surfaces
◆ Alteration in glycosaminoglycans
This is a process of?
sperm capacitation
◆ Modification or removal of sperm surface components by oviductal & uterine fluids
◆ Depletion of sperm cholesterol & glycoproteins at sperm surfaces
◆ Alteration in glycosaminoglycans
This is a process of?
sperm capacitation
- Fusion of plasma membrane and outer acrosomal membrane
- Vesiculation → release of acrosomal membrane
- Activation of different acrosomal enzymes
sperm capacitation
(2) acrosomal enzyme
- hyaluronidase
- acrosin
➔ Fusion of male & female gamete & forming a single cell zygote, then migrates to uterus
➔ Oocyte viable up to 18 hrs after ovulation
◆ Time the mating
● ovum/ova still viable
● Capacitated sperm to fertilize
FERTILIZATION
site of fertilization
Ampulla of the oviduct
In process of fertilization, migration of sperm between ______ _____
cumulus oophorus
migration of sperm is aided by (2)
a. hyaluronidase (most animals)
b. aryl sulfatase (boar)
As sperm migrates, and upon reaching ampulla, capacitated sperm will migrate between _____
and ___ ____ cells
cumulus &
corona radiata cells
Migrations among cells surrounding the
ovum are aided by _____ enymes
acrosomal enzymes
Process of fertilization:
a. Occurrence of acrosomal reaction
b. Occurs before or after sperm attaches to ZP3 receptors on zona pellucida
Passage of sperm to zona pellucida
Process of fertilization:
In passage of sperm to zona pellucida, Eventually, sperm penetrates zona pellucida (glycoprotein layer) → then acrosomal reaction takes
place → attachment to _____ receptors
ZP3 receptors
primary receptor for fertilization
ZP3 receptors
secondary receptor maintaining
sperm/egg contact
ZP2 receptors
Sperm penetration of zona ______
pellucida
Penetration of ______ membrane
vitelline
Zona pellucida reaction ensures ____ to prevent penetration of vitelline membrane of other sperms
monospermic fertilization
a. Male + female pronucleus
b. Formation of zygote (diploid state restored)
c. Zygote divides into two-cell
i. Hours after sperm penetration:
1. Sow - 12-14
2. Ewe - 16-21
3. Cow - 20-24
d. Migrates to uterus for implantation
fusion of gametes
