Assistive reproductive technologies Flashcards
advantages of embryo transfer
-increased yield from superior females
-increase yield from valuable semen
-transport maternal genetics
disadvantages of embryo transfer
-requires extensive training
-requires many semen straws
-labor-intensive
-expensive
steps for embryo transfer
superovulation
insemination
flushing
synchrony
embryo transfer
what day are embryos collected for ET
day 16(7-8 days old)
what method for insemination is used for sheep and deer
laparoscopic AI
how are embryos flushed out
catheter inserted through cervix, special media is flushed into and out of uterus to collect embryos
factors looked at in embryo grading
-even number of cells
-intact ZP
-uniform division
-no fragmented cells
how are embryos inserted
ultrasound to determine the location of CL, transfer embryo to uterine horn on the same side as the CL
IVF definition
collecting unfertilized oocytes directly from uterus, fertilized in a lab, transferred to a recipient
steps of IVF
-superovulation
-ovum pick up(OPU)
-grade oocytes
-in vitro maturation(oocyte maturation)
-in vitro fertilization
-culture embryos
-inseminate
ovum pick up
transvaginal removal of oocytes by aspirating the follicles with aid of ultrasound
what are oocytes being graded on for IVF
several intact layers of cumulus cells
what stage do oocytes need to be matured to for IVF? how long does it take?
metaphase II, about 24 hours
how long does it take between addition of sperm to oocytes to form embryos
8-20 hours
what stage do embryos need to be cultured to for IVF? how long does it take?
morula or blastocyst phase, approximately 5 days
what does ICSI stand for? what is it
intracytoplasmic sperm injection
single sperm injected directly into an oocyte
benefit of ICSI
enables use of genetically valuable sperm that has poor motility, acrosomal or other defects
what is gamete intrafallopian transfer(GIFT)
surgically transferring male and female gametes into the oviduct
what is somatic cell nuclear transfer(SCNT)
create genetically identical animals (cloning)
steps for SCNT
-nucleus of oocyte is removed(enucleation)
-nucleus of fully differentiated somatic cell is removed
-somatic cell nucleus is added to oocyte nucleus
-oocyte is stiimulated to “reset” the cell
-newly formed embryo should mature into genetically identical offspring
downsides of SCNT
-decreased genetic diversity
-expensive
-harder to prevent inbreeding
-more susceptible to loss from a single disease
T/F SCNT always produces a clone that is physically or temperamentally identical
FALSE
