Term
For fertilization to occur, sperm and oocyte must meet at a time when both are viable. Give an example of how each of the following can affect this timing?
a) Behaviors
b) Sperm factors
c) Oocyte factors |
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Definition
a) estrus
b) sperm factors
c) occyte factors |
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Term
| Give a very general descroption of sperm transport in the female. |
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Definition
-rapid phase = in th eoviduct in minutes
-await arrival of the oocytes
-result of muscle contraction following copulation
-sustianed phase = sperm delivered to oviducts continually from reservoirs in the: cervix, UTJ |
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Term
| How does the uterus change under E2 control? Sulfomucins? Sialomucins? |
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Definition
-changes in mucus production
-sulfomucins = high viscosity
-sialomucins = low viscosity |
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Term
| When does mucosal immunity start in response to sperm in the female? |
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Definition
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Term
| What are the different options for the fate of sperm? |
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Definition
-retrograde sperm loss
-retained in cervix (due to certain abnormalities)
-make it to oviduct
-phagocytosis |
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Term
| Where do sperm acquire maturity? Where do they acquire maximal fertility? |
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Definition
-sperm acquire maturity during passage through the epididymus
-maxima fertility acquired only after residing in the female tract (uterus mainly) for a minimal time period |
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Term
What is the fertile life of sperm inthe oviduct in the following species:
a) bitch
b) camelids
c) cow
d) mare |
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Definition
a) 9-11
b) 4-5
c) t.5-2
d) 4-5 |
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Term
| A typical ovulated oocye is enclosed by two layers. Describe them? |
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Definition
-outer layer is approx 5000 culules cells
-inner is thick extracellular matrix, the zona pelucida |
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Term
| Describe the process of fertilization. |
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Definition
-sperm bind transiently to the egg zona pellucida nd the egg plasma membrane and then fuse
-signaling in the sperm is induced by sperm adhesion to the zona pellucida
-signaling in the egg is induced by gamete fusion |
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Term
| In placental mammals, describe the structure of the ZP. |
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Definition
| -meshwork of three gropus of sulfated glycoproteins that completely encircles the oocyte |
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Term
| What is the zona pellucida responsible for? |
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Definition
-sperm binding ahd the subsequent induction of the acrosome reaction that allows sperm penetration
-allso a physical barrier to select for functional spermatozoa capable of successful penetration, to prevent polyspermy, and to protect early embryos |
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Term
| Is damage to the acrosome reversible? what are some common causes of acrosomal damage? |
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Definition
-irreversible = sperm will not be fertile
-changes in osmotic pressure, sudden temp change, marked changes in pH |
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Term
| Damage to the acrosome is often associated with what three things? |
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Definition
-chaanges in osmotic pressure
-sudden temp change
-marked changes in pH |
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Term
| What initiates the acrosome reaction? |
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Definition
| -ZP binding initiates acrosome reaction after capacitation exposes the ZP binding sites |
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Term
| If the acrosome reaction occurs prematures what happens? |
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Definition
| -sperm cannot penetrate ZP |
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Term
| Once the sperm penetrate the ZP, what space are they in? |
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Definition
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Term
| What is the cortical reation? |
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Definition
-ZP hardening and vitelline membrane changes
-sperm head attaches to oocyte plasma membrane )vitelline membrane and initiates block to polyspermy |
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Term
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Definition
| -sperm head enters oocyte (male and female pronuclei form) => nuclear membranes fuse (chromosomes match up) => restores 2N |
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Term
| Before the embryo can attach to the uteru what 4 things must occur? |
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Definition
-develop within ZP
-hatching
-maternal recognition
-formation of extraembryonic membranes |
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Term
| During which stage does embryo transfer occur? |
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Definition
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Term
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Definition
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Term
| What happens during the first division? Second and so on? |
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Definition
-First division: 2 blastomeres half the size of zygote
-Second division: 4 blastomeres uarter size of zygote |
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Term
| What structures tells us it is a secondary oocyte? |
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Definition
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Term
| What structure tells us it is a zygote? |
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Definition
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Term
| How large is the cow conceptus at D13? D17? Why is this important? |
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Definition
-D13 = 3mm & D17 250 mm
-Pig: D10 = 2m & D12 = 200 mm
-needs to be large enough for maternal recognition of pregnancy to occur |
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Term
| Describe post-hatching blastocyst growth in the ruminant. |
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Definition
-filamentous thread-like structure
-develops into opposite horn |
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Term
| Describe post-hatching blastocyst growth in the mare. |
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Definition
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Term
| Describe post-hatching blastocyst growth in the sow. |
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Definition
| -elongates like in the ruminant but you need two in EACH horn to maintain pregnancy |
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Term
| Why is extraembryonic membrane development important? |
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Definition
| -essential to facilitate attachement to the uterus |
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Term
| What are the attachment times for the cow, mare, and sow/ewe? |
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Definition
-Cow-: d18-22
-Mare: d36-45
-Sow/Ewe: d15-18 |
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