Altering Reproductive Processes
Animal
Breeding
Pensacola Jr College
Altering Reproduction - Methods
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Estrus synchronization
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Superovulation
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In-vitro fertilization
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Embryo transfer
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Induced parturition
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Contraception
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Biotechnology
Estrus Synchronization
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Manipulate estrous cycles in a group of females
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Make stages occur at uniform time in all
individuals
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Why?
Ease of AI in large groups
Offset calving in subgroups
Donor-recipient estrus timing in embryo transfer
Estrus Synchronization - Methods
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Exogenous progesterone, then single progesterone
+ estrogen injection
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One prostaglandin injection
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Inject GnRH, then
prostaglandin, then GnRH
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PMSG injections
Progesterone Implant,
P + E injection system
P Implant injection (ear)
CSU Synchronization Protocols
AI with synchronized estrus
Superovulation
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Artificial induction of ovulation of more than
normal number of eggs for the species
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Why?
More eggs for IVF or embryo transfer
Increasing reproductive potential
Superovulation - Methods
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Large dosages and frequencies of FSH injections,
sometimes with prostaglandin at the end
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Single large injected dose of PMSG in some
species
Superovulation Egg Collection
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Laparoscopic collection
Flush uterine contents out through infundibulum
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Non-surgical collection
Foley catheter with inflatable cuff seals off
uterus
Flush fluids into uterus and back out with egg
cells
Egg Aspiration
Foley Catheter
Demo use of Foley catheter
Demo use of Foley catheter
In-Vitro Fertilization
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Fertilization outside the body (i.e. test tube
babies)
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Why?
Increase reproductive potential
Reproduction of females with blocked oviducts
Embryo transfer
Genetic manipulation
IVF Method (steps)
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Collect sperm and culture with GAG heparin
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Collect ovulated or preovulatory
eggs in appropriate medium
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Incubate sperm and eggs together
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Use special medium to get past 2-cell block, to
blastula
IVF preparations
IVF
IVF Embryo
Embryo Transfer
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Implant embryos developed from IVF of one
individual into another
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Why?
Increase reproductive potential
Move embryos instead of adults (and may implant
in other species)
Use of infertile animals
Embryo Transfer needs
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Embryo evaluation:
Morula or early
blastula stage
Compact
Spherical
Normal size and stage
Zona pellucida even
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Recipient:
Healthy and synchronized
Well-formed CL
Embryo Storage for transfer
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Appropriate medium changed frequently
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Can be kept at room temperature for hours
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Can be kept at cool temperature for days
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Freezing in liquid nitrogen reduces pregnancy
rate
Embryo Transfer - Problems
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Excessive number of implantations (due to more
than normal # of embryos transferred)
Low birth weights
Spontaneous abortions
Retained placentas
Stress on mother
Insufficient lactation
Embryo Grading for Transfer Day 3 embryos
Grade 4 (best, no fragmenting)
Grade 3
Grade 2
Grade 1
Grade 0
Blastocyst for transfer
Frozen Embryo Zoo
Interspecies E.T.
Induced Parturition
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Artificial induction of labor / birth
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Why?
Overdue offspring
Management of group birthing
Synchronized offspring ages
Slightly increased reproductive potential (a few
days)
Induced Parturition - methods
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Oxytocin
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Corticosteroids
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Dexamethasone
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prostaglandin
Oxoject injection (oxytocin)
Lutalyse injection (pglandin)
Blocking Repro in male
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Castration
Surgical removal of testes and epididymides
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Vasectomy
Surgical severing of vas deferens
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Penile block
Tube and pin in sheath
Blocking Repro in male
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Redirection of prepuce
Surgical movement of prepuce opening to the side
Penis cannot line up with vulva for copulation
Castration Procedure, Dog
Blocking Repro in female
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Ovariohysterectomy
Surgical removal of ovaries and uterus
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Ovariectomy
Surgical removal of ovaries
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Tubal ligation
Surgical severing of oviducts
Blocking Repro in female
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Androgenization
Testosterone (oral or injected) to prevent
cycling
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Administration of female hormones - prevent
ovulation
Synthetic progesterone and estrogen derivatives
Pills, injections, or implants
Ovariohysterectomy Procedure, Bitch
Biotechnology
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Sex determination and selection
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Genetic recombination
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Cloning
Sex Selection
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IVF + sex embryos
Y-specific DNA probes of cells taken from embryo
(costly and harmful)
H-Y antigen test (non-invasive, 85% accuracy)
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Sperm sorting by X vs. Y
X weighs more, add charge with laser, separate
by charge
90% accurate, slow, expensive
Step 1:
Removing Embryo Cells
Step 2:
Y-specific DNA probing
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SPERM SORTING
Genetic Recombination
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Splice gene from one embryo into chromosomes of
another embryo
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Adult will have gene in all or most cells and
pass it on
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Why?
Curing a problem in a line
Beginning a line which will produce a lot of a
substance
Cloning
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Creating a copy
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Methods:
Starve cells from embryo or adult (make totipotent)
Remove nucleus from egg cell
Take nucleus from totipotent
cell and fuse with egg cell
Egg cell gives development factors, nucleus
gives genetics
Cloning
Transgenic Cloning
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Combine cloning and genetic recombination
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Can contain DNA for production of large quantity
of specific proteins ΰ
pharming
Cloning and Pharming:
Case Studies
Where are zoos headed today with
reproductive biotechnology?
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Readings
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Example strong programs: