Assisted Reproductive Techniques Flashcards
name 4 ADVANTAGES for EMBRYO TRANSFER
- embryo can be SHIPPED
- can TREAT/WASH for DISEASE CONTROL
- can BIOPSY for GENDER PRESELECTION/GENETIC SCREENING
- CRYOPRESERVATION for genetic banking or timed transfer
how does embryo transfer work? (4 steps)
- BREED DONOR FEMALE –> she needs to be pregnant for a short amount of time
- once embryo is in the uterus, FLUSH IT OUT OF THE LUMEN around 7 DAYS AFTER OVULATION
- once we recover embryo, can biopsy, transfer, treat/wash, etc.
- transfer into UTERUS of RECIPIENT
what are 2 complicating factors of embryo transfer?
- RECIPIENT must be in RIGHT STAGE OF ESTRUS (cannot be in heat)
- embryo CANNOT BE DAMAGED AFTER TAKING IT OUT
why is embryo transfer used in cattle?
because we can SUPEROVULATE via FSH (to MAKE FOLLICLES) and LH (to make follicles OVULATE) to CAUSE MANY DOMINANT FOLLICLES and recover MULTIPLE EMBRYOS
is SUPEROVULATION possible in the horse? why?
NO, because the OVULATION FOSSA makes sure that OVULATION ONLY OCCURS HERE
the DONOR ANIMAL in embryo transfer must be able to SUPPORT IT UNTIL ___ DAYS GESTATION
7
if embryos cannot be flushed from the uterus, they can be recovered from WHERE & HOW?
from OVIDUCT via SURGERY
how is the embryo transferred to the recipient in cows, horses and small ruminants?
COWS = TRANSCERVICAL
HORSE = TRANSCERVICAL
SMALL RUMINANTS = LAPAROSCOPY
the RECIPIENT of the embryo transfer must be ___ with the ___ of the embryo
synchronized, age
name 3 advantages of embryo transfers
- can be performed by ONE VET (check stage in cycle, move embryo and transfer)
- can INCREASE NUMBER OF OFFSPRING from valuable females (super ovulation)
- can produce offspring from females NOT ABLE TO CARRY FETUS TO TERM
why should we give DONOR mares PROSTAGLANDIN when taking out EMBRYO?
so that SHE WILL CYCLE AGAIN IN 7-10 DAYS
4 DISADVANTAGES of embryo transfer?
- increased level of skill needed
- increased cost
- LIMITED number of embryos can be recovered in horses –> ONE PER ~21 day cycle in the mare
- HIGH LABOR TO EMBRYO RATIO
embryo cryopreservation…
definition?
pregnancy rates when compared with FRESH embryos?
definition = FREEZE embryo or VITRIFY WELL
SAME or SLIGHTLY LOWER PREGNANCY RATES
if equine blastocysts are CRYOPRESERVED WITHOUT MANIPULATION, causes ___ pregnancy rates
LOW
BEFORE collecting equine blastocyst, we need to do WHAT?
COLLAPSE IT VIA MICRO-PIPETTE and then VITRIFY IT
how is EMBRYO BIOPSY performed in RUMINANTS vs. HORSES?
RUMINANTS –> use a MICROBLADE and AVOID INNER CELL MASS
HORSE –> use a PIPETTE and MICROMANIPULATION
what are SNP chips?
used for SELECTION of EMBRYOS for…
use DNA we get from EMBRYONIC BIOPSY, put it into computer and it can tell GENETIC INFORMATION
used for SELECTION of EMBRYOS for BEEF AND DAIRY CATTLE
in-vitro fertilization = ???
putting SPERM INTO PETRI DISH and FERTILIZE OOCYTES THERE
6 MAIN species that undergo IN VITRO FERTILIZATION?
(experimentally in ___)
- CATTLE (done mostly)
- SHEEP
- GOATS
- PIGS
- DOGS
- CATS
(experimentally in horses)
in vitro fertilization requires… (2)
- recovering OOCYTES FROM IMMATURE FOLLICLES in DONOR FEMALE
- SHIP THEM TO ART lab
when performing STANDARD in vitro fertilization, we must do what 2 things?
- CAPACITATE sperm
- CULTURE THE EARLY EMBRYO
ADVANTAGES to IVF? (4)
- INCREASED number of offspring from VALUABLE FEMALES (10-20 oocytes/week from cows)
- REDUCED LABOR compared to EMBRYO TRANSFER
- NO NEED FOR FUNCTIONAL TUBULAR TRACT –> just functional ovaries
- can produce offspring from sperm with LOW VIABILITY or SMALL STORES
DISADVANTAGES of IVF? (3)
- requires expertise to RECOVER OOCYTES FROM DONORS
- requires EXTENSIVE EXPERTISE & EQUIPMENT AT LAB
- increased expense to OWNER
INTRACYTOPLASMIC SPERM INJECTION…
used for fertilization in WHAT species?
how is it done?
we’re able to COLLECT AND FERTILIZE ___ oocytes, moreso than ___ ___
used in HORSES
how is it done? = pick up sperm in MICROPIPETTE and INJECT INTO MATURE OOCYTE
we’re able to COLLECT AND FERTILIZE MULTIPLE oocytes, moreso than EMBRYO TRANSFER
