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Animal Biotechnology Exam 3
n/a
107
Agriculture
Undergraduate 4
11/19/2011

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Cards

Term
Define embryo transfer
Definition
the transfer of an embryo from one female(donor) transferred to another female(recipient) to complete gestation
Term
A better term for superovulation would be..
Definition
follicular stimulation
Term
What are some reasons for embryo transfer?
Definition

Increase the number of offspring from selected females

increase offspring from selected males

import/export of genetics

research

Term
Why would embryo transfer be an advantage for native resistance to disease from recipients?
Definition
Embryos born to native cattle will obtain the immunity from the colostrum of the native cow
Term
How is embryo transfer used in genetic testing of bulls?
Definition
Progeny testing and used to identify recessive traits
Term
Which continents represent the majority that use embryo transfer?
Definition
North and South America
Term
Why is it important to superovulate a cow before the dominant follicle appears?
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
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.
Definition
"Dam" effect
Term
Injections timed during a natural cycle or the cycle is controlled by ___
Definition
progesterone
Term
CIDR
Definition
Controlled Intravaginal Drug Releasing device
Term
What is the conventional superovulation protocol in cows?
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

Term
What is the superovulation protocol with a CIDR?
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

Term
Which method of collection is usually used in cows? non-surgical or surgical?
Definition
non-surgical collection (flushing)
Term
When is embryo collection usually in cows?
Definition
7 days after estrus
Term
What type of solution is used when flushing for embryos?
Definition
a simple saline solution
Term
What stage will the embryos be upon collection?
Definition
morula or blastocyst
Term
What is the average number of viable embryos collected?
Definition
6
Term
Where will the embryo be deposited in the recipient cow?
Definition
uterine horn, same side as the CL
Term
It's important to not manipulate the uterine horn too much during transfer because ___
Definition
It will cause the release of PGs that will cause the CL to regress aborting the embryo
Term
Synchrony between donor and recipient is __
Definition
+/- 24 hrs
Term
What is the expected pregnancy rate in embryo transfer?
Definition
50-70%
Term
What factors affect the pregnancy rate in embryo transfer?
Definition
recipient management: "quality" age, fertility, condition
Term
What are some applications of in vitro embryo production?
Definition
  • research
  • support other embryo technologies: cloning, transgenic animals, biomedical applications
  • assisted reproduction in domestic animals: production of animals 
Term
What are the 3 components of in vitro embryo production?
Definition
  • In Vitro Oocyte Maturation (IVM)
  • In Vitro Fertilization (IVF)
  • In Vitro Culture (IVC) 
Term
What happens in IVM?
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
Term
Abattoir dervived is the term used for ___
Definition
Oocytes collected from random ovaries from unknown sources, usually in a slaughter house
Term
If a follicle is too large, what does this do to the effiency of aspiration?
Definition
will decrease
Term
Cumulus cells around the oocyte are essential for ____
Definition
maturation
Term
What happens in IVF?
Definition
Mixing of mature oocyte expanded cumulus cell complexes with sperm
Term
How are the motile sperm separated?
Definition
Percoll separation(density gradient material) or swim up method
Term
What induces capacitation of the sperm in IVF?
Definition
GAGs, Heparin
Term
What are GAGs?
Definition

Glycosaminoglycan

Polysaccharides with high molecular weight that contain amino sugars and often form complexes with proteins

Term
GAGs high in _____ at ovulation also in expanded CC matrix
Definition
oviductal fluid
Term
What happens in IVC?
Definition

One cell fertilized ovum to blastocyst stage (7 days)

culture through maternal to zygotic transition

Co-culture, culture with other cells

 

Term
Why do we usually culture without co-culture?
Definition
Improved culture media and conditions
Term
What type of medium is used in IVF?
Definition
Simple mediums: salts, lactate, pyruvate
Term
What type of media is used in IVC?
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

Term
Why would we use a low glucose medium?
Definition
embryos don't utilize glucose, they use lactate or pyruvate, therefore its better to use low or no glucose
Term
How are In Vitro produced embryos used in commercial cattle production?
Definition

treatment of infertility- cattle that don't respond to superovulation

cattle of normal fertility- number of embryos in a short period of time

Term
How are In Vitro produced embryos used in dairy production?
Definition

Production of F1 crossbreeds

dairy replacement heifers in beef herds

incorporation of sex control to produce only females

Term
How is IVP used in other domestic animals (other than cattle)?
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 
Term
What are some reasons for embryo cryopreservation?
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 
Term
What are the steps of cryopreservation?
Definition
  • addition of cryoprotectant
  • loading
  • freezing
  • thawing
  • removal of cryoprotectant 
Term
What is the difference between penetrating and non penetrating cryoprotectants?
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

Term
Comparing water and cryoprotectant movement across the membrane, which will move faster?
Definition
water will always move faster
Term
What happens when adding the cryoprotectant?
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.
Term
What is the solution to the problem of water moving out of the cell faster than cryoprotectant moving in?
Definition
step wise addition- gradually increase concentration of CPs
Term
A straw has a very high surface to volume ratio, meaning it will change temperature ___
Definition
very easily and rapidly
Term
What is the problem with embryo freezing?
Definition
If there's any water inside the cell it will freeze causing ice crystals that can damage the cell.
Term
What is the solution to water freezing inside the cell?
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

Term
What is the problem with thawing?
Definition
There are usually small ice crystals present inside the cells; as thawing starts ice crystals grow
Term
What is the solution to the problem of thawing?
Definition
Thaw rapidly to prevent ice crystal growth
Term
What is the problem during the removal of CPs?
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.
Term
What is the solution in the removal of CPs?
Definition

Step wise removal of the CPs

Use of non penetrating compounds (sucrose) to prevent water movement until CP leaves

Term
Which is the preferred CP and why?
Definition
ethylene glycol because it enters and leaves the cell rapidly
Term
When an embryo is thawed and transferred without any manipulation
Definition
direct transfer
Term
What is vitrification?
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

Term
The ability to survive freeze and thaw
Definition
cryotolerance
Term
What are some factors that may affect cryotolerance?
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

Term
Why do early stage equine embryos have a higher cryotolerane than later stage embryos?
Definition
Later stage embryos develop a chorion which is impermeable to any CPs
Term
What is the major limiting factor in the widespread application of embryo biotechnologies?
Definition
lack of cryotolerance
Term
ICSI
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
Term
The mechanical opening (cutting, slitting, drilling) the zona over a certain area, thins the zona pellucida
Definition
assisted hatching
Term
Assisted hatching has been primarily used in ____ IVF
Definition
human
Term
Embryo splitting is the separation of the ____
Definition
blastomere to make twin, triplets, and quads
Term
What stage of embryo is preferred for embryo splitting?
Definition
morula
Term
What are the gender control methods in domestic animals?
Definition
  • embryo sexing
  • fetal sexing
  • semen sexing  
Term
What are the different methods of embryo sexing?
Definition
  • Karyotyping
  • x-linked enzyme method
  • H-Y antigen
  • PCR- used to identify sequences that are sex specific (Y) 
Term
Which is the simplest approach in embryo sexing?
Definition
Karyotyping- uses chromosomal analysis, chromosomes have to be in metaphase, ~60% successful at determining sex
Term
What enzyme are we testing for during x-linked enzymatic activities?
Definition
glucose-6-phosphate dehydrogenase
Term
What does the "H" stand for in H-Y Antigen?
Definition
Histocompatibility
Term
Which method of gender control is the most reliable?
Definition
Polymerase Chain Reaction
Term
What happens during PCR in embryo sexing?
Definition
amplification of male specific DNA sequences on Y chromosome
Term
In semen sexing, the X chromosome will be ____ than the Y
Definition
bigger
Term
During semen sexing, they are sorted by their differnce in size by ____
Definition
Flurescent Activated Cell Sorting (FACS)
Term
What is the superovulation protocol for sheep and goats?
Definition

day 0-11: P4 (CIDR)

day 8-11: FSH 2x daily

day 10: PG

day 14: mating

Term
The type of collection and transfer used in sheep and goats is ___
Definition
surgical
Term
What is the reasonable alternative to full on surgical transfer in sheep and goats?
Definition
Laparoscopic Aided Transfer
Term
When a sheep or goat is out of season, what does this do to the pregnancy rate after transfer?
Definition
It will decrease
Term
How much semen is used in AI for pigs? Why?
Definition
200-300 mL because the sow has the longest uterine horns, there needs to a large number of motile sperm
Term
The major reason for embryo transfer in pigs is __
Definition
Research
Term
This is used in pigs to control the estrous cycle
Definition
Altrenogest (Matrix)
Term
This is used in the superovulation of pigs
Definition
PMSG (Pregnant Mare Serum Gondaotropin/ eCG)
Term
Altrenogest (Regumate in horses, Matrix for pigs) is an orally active progestagin that is fed daily for ____ days
Definition
14
Term
How many females will come into estrus after end of altrenogest treatment?
Definition
80%
Term
Collection and transfer of embryos in a pig are done ___
Definition
surgically
Term
Non surgical collection and transfer of embryos in horses is ____
Definition
highly successful
Term
Why is it hard to superovulate a mare?
Definition
Ovulates from the ovulation fossa, when superovulated all travel to that one spot
Term
Why would embryo transfer be used in horses?
Definition
to produce offspring while still in competition
Term
Mares are what type of breeders?
Definition
long day breeders
Term
producing a population of something from a single individual
Definition
cloning
Term
What happens to genetic information during differentiation?
Definition
nothing, its not lost
Term
What is it called when a specialized cell is reprogrammed to a non differential cell?
Definition
Reprogramming
Term
What are some issues with cloning?
Definition

low effiency

developmental abnormalities

Term
What are some applications of cloning?
Definition
  • research
  • transgenic animals
  • agricricultural production 
Term
ability to differentiate into any cell type
Definition
totipotent
Term
can develop into a large array of different cell types except placental
Definition
pluripotent
Term
develop into some cell types but are restricted, most tissues contain stem cell population that can regenerate that tissue
Definition
multipotent
Term
the diploid cell resulting from the fusion of the male and female pronuclei
Definition
zygote
Term
composed of a population of cells that can replicate themselves for long periods of time in vitro
Definition
stem cell lines
Term
What are the 3 embryonic germ layers?
Definition

endoderm

mesoderm

ectoderm

Term
What is the important characteristic of embryonic stem cells?
Definition
unlimited self-renewal
Term
what is a progenitor cell?
Definition
It's like a stem cell, not differentiated but determined to go in that direction
Term
What is the most important characteristic of stem cells?
Definition
self-regeneration
Term
What does plasticity mean?
Definition
goes from uni to multipotent
Term
Which are the most studied adult stem cells?
Definition
Hematopoietic Stem cells- bone marrow and cord blood cells
Term
What are the main cells used for adult stem cells?
Definition
bone marrow, fat, cartilage, nueronal
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