AGR 506 Spermatozoa in Female Tract

What species is the semen deposited into the vagina?

-Cow

-Sheep

-Rabbit

-Primates

-Dog

-Cat

What species’ is the semen deposited into the cervix?

Pigs

What species is the semen deposited into the cervical lumen?

Horse

What is Intracervical insemination?

Semen is delivered into cranial half of cervix and flows directly into uterine horns (procedure in pigs)

What is Intercornual transport and why is it important?

Semen redistributed into both uterine horns

Depositing into just one horn is not beneficial

What is Transcervical insemination?

Semen delivered by pipette to penetrate and bypass cervix

What is Intravaginal insemination?

Semen deposited into cranial vagina (Procedure in Cats and Dogs)

What can cause spermatozoal loss?

-Retrograde Loss

-Neutrophils attacking foreign material (sperm)

What does the sperm do during the sustained phase of spermatozoal transport?

-Sperm move into isthmus and attach to oviductal epithelium (inner layer)

-Temporarily docks to the epithelium

-Elicits signal cascade in sperm that promotes viability

How fast after copulation can sperm be found in the oviducts? Are these sperm viable?

Few minutes

No, they are not viable

What is the major barrier to spermatozoal transport?

The Cervix

What species does the sperm have to travel through a convoluted system of grooves within the cervix?

Cows and Ewes

(To some degree in the mare)

What is Spermatozoal capacitation?

When sperm enters the female reproductive tract the sperm goes through changes that allows them to become fertile

What happens when sperm enters the oviduct?

Become hyperactive and facilitates sperm-oocyte contact

What are the zone binding sites and what do they do?

Primary zone binding region- responsible for adherence of spermatozoa to zona pellucida

Second binding site- acrosome reaction promoting ligand

What is the acrosomal reaction?

-Enables spermatozoa to penetrate zona pellucida

-Modifies equatorial segment so it can later fuse with plasma membrane of oocyte

-Release of acrosomal enzymes allows spermatozoon to digest its way through zona pellucida

What is Syngamy?

Fusion of male and female pronuclei

What is Polyspermy? What does it result in?

Multiple sperm fertilizing an oocyte

Embryo Death

What prevents polyspermy?

Zona and vitelline block to allow only one sperm to fertilize oocyte

What is the fertile period?

The fertile lifespan of sperm after deposition in female tract varies among species

In which species is semen deposited into the cranial cervix?

Pig

Multiple sperm fertilizing an oocyte (polyspermy) is prevented by ________.

Both zona block and vitelline block depending on species

Which type of artificial insemination should be utilized on dogs?

Intravaginal insemination

True or False: Neutrophils attack foreign material but they do not recognize sperm as foreign material in the female reproductive tract.

False

True or False: The cervix is a major barrier to spermatozoal transport and also serves as a reservoir for spermatozoa.

True