Term
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Definition
the transfer of an embryo from one female(donor) transferred to another female(recipient) to complete gestation |
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Term
A better term for superovulation would be.. |
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Definition
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Term
What are some reasons for embryo transfer? |
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Definition
Increase the number of offspring from selected females
increase offspring from selected males
import/export of genetics
research |
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Term
Why would embryo transfer be an advantage for native resistance to disease from recipients? |
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Definition
Embryos born to native cattle will obtain the immunity from the colostrum of the native cow |
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Term
How is embryo transfer used in genetic testing of bulls? |
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Definition
Progeny testing and used to identify recessive traits |
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Term
Which continents represent the majority that use embryo transfer? |
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Definition
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Term
Why is it important to superovulate a cow before the dominant follicle appears? |
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Definition
The dominant follicle will cause the other follicles in the cohort to regress. If superovulated at the beginning of the follicular wave, before the appearance of the dominant follicle, the smaller follicles in the cohort will be rescued |
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Term
When superovulated with FSH, this will cause a _____ effect. Ovulation of the cohort won't happen until P4 levels decrease causing the release of multiple follicles. |
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Definition
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Term
Injections timed during a natural cycle or the cycle is controlled by ___ |
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Definition
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Term
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Definition
Controlled Intravaginal Drug Releasing device |
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Term
What is the conventional superovulation protocol in cows? |
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Definition
Day 9-12(4 days): FSH injections
Inject PGF day 12
AI 24 hrs after PGF
Collect embryos 6-8 days after first AI |
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Term
What is the superovulation protocol with a CIDR? |
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Definition
Insert CIDR day 1 of cycle
Day 4-7: FSH injections
Day7: inject PGF and remove CIDR
Day 8: Expect estrus and AI
Day 15: collect embryos |
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Term
Which method of collection is usually used in cows? non-surgical or surgical? |
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Definition
non-surgical collection (flushing) |
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Term
When is embryo collection usually in cows? |
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Definition
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Term
What type of solution is used when flushing for embryos? |
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Definition
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Term
What stage will the embryos be upon collection? |
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Definition
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Term
What is the average number of viable embryos collected? |
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Definition
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Term
Where will the embryo be deposited in the recipient cow? |
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Definition
uterine horn, same side as the CL |
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Term
It's important to not manipulate the uterine horn too much during transfer because ___ |
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Definition
It will cause the release of PGs that will cause the CL to regress aborting the embryo |
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Term
Synchrony between donor and recipient is __ |
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Definition
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Term
What is the expected pregnancy rate in embryo transfer? |
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Definition
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Term
What factors affect the pregnancy rate in embryo transfer? |
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Definition
recipient management: "quality" age, fertility, condition |
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Term
What are some applications of in vitro embryo production? |
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Definition
- research
- support other embryo technologies: cloning, transgenic animals, biomedical applications
- assisted reproduction in domestic animals: production of animals
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Term
What are the 3 components of in vitro embryo production? |
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Definition
- In Vitro Oocyte Maturation (IVM)
- In Vitro Fertilization (IVF)
- In Vitro Culture (IVC)
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Term
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Definition
Immature oocyte cumulus cell complexes from abattoir material (unknown source) or aspirated from selected individuals by ultrasound guided aspiration. Oocyte cumulus cell complexes put in tissue culture medium, plus serum and gonadotropins. Incubation 22-24 hours. Nuclear maturation to metaphase II stage of oocyte. Cumulus cell expansion. Production of intercellular matrix and GAGs |
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Term
Abattoir dervived is the term used for ___ |
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Definition
Oocytes collected from random ovaries from unknown sources, usually in a slaughter house |
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Term
If a follicle is too large, what does this do to the effiency of aspiration? |
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Definition
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Term
Cumulus cells around the oocyte are essential for ____ |
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Definition
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Term
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Definition
Mixing of mature oocyte expanded cumulus cell complexes with sperm |
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Term
How are the motile sperm separated? |
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Definition
Percoll separation(density gradient material) or swim up method |
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Term
What induces capacitation of the sperm in IVF? |
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Definition
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Term
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Definition
Glycosaminoglycan
Polysaccharides with high molecular weight that contain amino sugars and often form complexes with proteins |
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Term
GAGs high in _____ at ovulation also in expanded CC matrix |
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Definition
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Term
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Definition
One cell fertilized ovum to blastocyst stage (7 days)
culture through maternal to zygotic transition
Co-culture, culture with other cells
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Term
Why do we usually culture without co-culture? |
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Definition
Improved culture media and conditions |
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Term
What type of medium is used in IVF? |
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Definition
Simple mediums: salts, lactate, pyruvate |
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Term
What type of media is used in IVC? |
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Definition
simple media: salts, lactate, pyruvate, glucose low or omitted during early stages, amino acids, Bovine serum albumin during early stages
sequential media: first 3-4 days lactate, pyruvate, BSA
day3 or 4 glucose, serum |
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Term
Why would we use a low glucose medium? |
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Definition
embryos don't utilize glucose, they use lactate or pyruvate, therefore its better to use low or no glucose |
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Term
How are In Vitro produced embryos used in commercial cattle production? |
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Definition
treatment of infertility- cattle that don't respond to superovulation
cattle of normal fertility- number of embryos in a short period of time |
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Term
How are In Vitro produced embryos used in dairy production? |
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Definition
Production of F1 crossbreeds
dairy replacement heifers in beef herds
incorporation of sex control to produce only females |
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Term
How is IVP used in other domestic animals (other than cattle)? |
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Definition
- Porcine- IVM unfertilized oocytes for nuclear transfer; IVF and IVC- poor, poly spermic fertilization
- Sheep/goats- IVM unfertilized oocytes for nuclear transfer; IVF and IVC- marginal
- equine- IVM marginal; IVF and IVC- poor
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Term
What are some reasons for embryo cryopreservation? |
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Definition
- long term storage of embryos in frozen state
- recipient management- more embryos than recipients at time of collection, use of recipients at different locations
- import/export
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Term
What are the steps of cryopreservation? |
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Definition
- addition of cryoprotectant
- loading
- freezing
- thawing
- removal of cryoprotectant
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Term
What is the difference between penetrating and non penetrating cryoprotectants? |
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Definition
Penetrating cryoprotectants enter the cell and replace the water. They are made up of DMSO, glycerol, and ethylene glycol. Has a low molecular weight.
Non penetrating cryoprotectants don't enter the cell but instead accumulate sugars around the structure for protection. These sugars are sucrose, trehalose, and glucose. Has a large molecular weight |
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Term
Comparing water and cryoprotectant movement across the membrane, which will move faster? |
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Definition
water will always move faster |
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Term
What happens when adding the cryoprotectant? |
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Definition
Water will move out of the cell causing it to shrink. The cryoprotectant will move into the cell but at a slower rate. The cell will re-expand as cryoprotectant moves in. |
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Term
What is the solution to the problem of water moving out of the cell faster than cryoprotectant moving in? |
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Definition
step wise addition- gradually increase concentration of CPs |
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Term
A straw has a very high surface to volume ratio, meaning it will change temperature ___ |
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Definition
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Term
What is the problem with embryo freezing? |
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Definition
If there's any water inside the cell it will freeze causing ice crystals that can damage the cell. |
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Term
What is the solution to water freezing inside the cell? |
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Definition
CPs displace water inside the cell but not all of it. Water outside of the cell will freeze first and grow ice crystals which will draw water from inside the cell.
Must cool slowyly to allow water to move
at ~35 C rapidly lower temp to liquid nitrogen |
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Term
What is the problem with thawing? |
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Definition
There are usually small ice crystals present inside the cells; as thawing starts ice crystals grow |
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Term
What is the solution to the problem of thawing? |
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Definition
Thaw rapidly to prevent ice crystal growth |
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Term
What is the problem during the removal of CPs? |
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Definition
As CPs leave the cell, water will move back into cell at a faster rate causing the celll to swell and cause cell lysis. |
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Term
What is the solution in the removal of CPs? |
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Definition
Step wise removal of the CPs
Use of non penetrating compounds (sucrose) to prevent water movement until CP leaves |
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Term
Which is the preferred CP and why? |
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Definition
ethylene glycol because it enters and leaves the cell rapidly |
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Term
When an embryo is thawed and transferred without any manipulation |
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Definition
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Term
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Definition
very rapid freezing without ice crystal formation (formation of glass)
requires very high concentrations of CP (4x greater)
high surface to volume ratio to obtain freezing rate |
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Term
The ability to survive freeze and thaw |
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Definition
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Term
What are some factors that may affect cryotolerance? |
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Definition
- species-porcine(don't survive freeze thawing), equine(don't survive)
- stage of development- bovine(day 5 lack chill tolerance), porcine(pre-hatched blastocyst don't survive, later dev. embryos dev. some tolerance), equine(after day 7-early stage embryos have better tolerance than later stage)
- effect of manipulation
**Bovine embryos have high degree of tolerance |
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Term
Why do early stage equine embryos have a higher cryotolerane than later stage embryos? |
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Definition
Later stage embryos develop a chorion which is impermeable to any CPs |
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Term
What is the major limiting factor in the widespread application of embryo biotechnologies? |
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Definition
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Term
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Definition
Intra Cytoplasmic Sperm Injection
- used in human ART (assisted reproductive technologies)- failure of IVF, male infertility, highly successful
- not used in animal breeding- limited application, lack of activation of oocyte, not very successful
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Term
The mechanical opening (cutting, slitting, drilling) the zona over a certain area, thins the zona pellucida |
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Definition
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Term
Assisted hatching has been primarily used in ____ IVF |
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Definition
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Term
Embryo splitting is the separation of the ____ |
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Definition
blastomere to make twin, triplets, and quads |
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Term
What stage of embryo is preferred for embryo splitting? |
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Definition
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Term
What are the gender control methods in domestic animals? |
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Definition
- embryo sexing
- fetal sexing
- semen sexing
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Term
What are the different methods of embryo sexing? |
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Definition
- Karyotyping
- x-linked enzyme method
- H-Y antigen
- PCR- used to identify sequences that are sex specific (Y)
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Term
Which is the simplest approach in embryo sexing? |
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Definition
Karyotyping- uses chromosomal analysis, chromosomes have to be in metaphase, ~60% successful at determining sex |
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Term
What enzyme are we testing for during x-linked enzymatic activities? |
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Definition
glucose-6-phosphate dehydrogenase |
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Term
What does the "H" stand for in H-Y Antigen? |
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Definition
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Term
Which method of gender control is the most reliable? |
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Definition
Polymerase Chain Reaction |
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Term
What happens during PCR in embryo sexing? |
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Definition
amplification of male specific DNA sequences on Y chromosome |
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Term
In semen sexing, the X chromosome will be ____ than the Y |
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Definition
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Term
During semen sexing, they are sorted by their differnce in size by ____ |
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Definition
Flurescent Activated Cell Sorting (FACS) |
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Term
What is the superovulation protocol for sheep and goats? |
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Definition
day 0-11: P4 (CIDR)
day 8-11: FSH 2x daily
day 10: PG
day 14: mating |
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Term
The type of collection and transfer used in sheep and goats is ___ |
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Definition
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Term
What is the reasonable alternative to full on surgical transfer in sheep and goats? |
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Definition
Laparoscopic Aided Transfer |
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Term
When a sheep or goat is out of season, what does this do to the pregnancy rate after transfer? |
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Definition
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Term
How much semen is used in AI for pigs? Why? |
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Definition
200-300 mL because the sow has the longest uterine horns, there needs to a large number of motile sperm |
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Term
The major reason for embryo transfer in pigs is __ |
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Definition
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Term
This is used in pigs to control the estrous cycle |
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Definition
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Term
This is used in the superovulation of pigs |
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Definition
PMSG (Pregnant Mare Serum Gondaotropin/ eCG) |
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Term
Altrenogest (Regumate in horses, Matrix for pigs) is an orally active progestagin that is fed daily for ____ days |
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Definition
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Term
How many females will come into estrus after end of altrenogest treatment? |
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Definition
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Term
Collection and transfer of embryos in a pig are done ___ |
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Definition
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Term
Non surgical collection and transfer of embryos in horses is ____ |
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Definition
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Term
Why is it hard to superovulate a mare? |
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Definition
Ovulates from the ovulation fossa, when superovulated all travel to that one spot |
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Term
Why would embryo transfer be used in horses? |
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Definition
to produce offspring while still in competition |
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Term
Mares are what type of breeders? |
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Definition
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Term
producing a population of something from a single individual |
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Definition
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Term
What happens to genetic information during differentiation? |
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Definition
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Term
What is it called when a specialized cell is reprogrammed to a non differential cell? |
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Definition
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Term
What are some issues with cloning? |
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Definition
low effiency
developmental abnormalities |
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Term
What are some applications of cloning? |
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Definition
- research
- transgenic animals
- agricricultural production
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Term
ability to differentiate into any cell type |
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Definition
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Term
can develop into a large array of different cell types except placental |
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Definition
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Term
develop into some cell types but are restricted, most tissues contain stem cell population that can regenerate that tissue |
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Definition
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Term
the diploid cell resulting from the fusion of the male and female pronuclei |
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Definition
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Term
composed of a population of cells that can replicate themselves for long periods of time in vitro |
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Definition
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Term
What are the 3 embryonic germ layers? |
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Definition
endoderm
mesoderm
ectoderm |
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Term
What is the important characteristic of embryonic stem cells? |
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Definition
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Term
what is a progenitor cell? |
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Definition
It's like a stem cell, not differentiated but determined to go in that direction |
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Term
What is the most important characteristic of stem cells? |
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Definition
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Term
What does plasticity mean? |
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Definition
goes from uni to multipotent |
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Term
Which are the most studied adult stem cells? |
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Definition
Hematopoietic Stem cells- bone marrow and cord blood cells |
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Term
What are the main cells used for adult stem cells? |
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Definition
bone marrow, fat, cartilage, nueronal |
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