Assistive reproductive technologies

Question 1

advantages of embryo transfer

Answer 1

-increased yield from superior females
-increase yield from valuable semen
-transport maternal genetics

Question 2

disadvantages of embryo transfer

Answer 2

-requires extensive training
-requires many semen straws
-labor-intensive
-expensive

Question 3

steps for embryo transfer

Answer 3

superovulation
insemination
flushing
synchrony
embryo transfer

Question 4

what day are embryos collected for ET

Answer 4

day 16(7-8 days old)

Question 5

what method for insemination is used for sheep and deer

Answer 5

laparoscopic AI

Question 6

how are embryos flushed out

Answer 6

catheter inserted through cervix, special media is flushed into and out of uterus to collect embryos

Question 7

factors looked at in embryo grading

Answer 7

-even number of cells
-intact ZP
-uniform division
-no fragmented cells

Question 8

how are embryos inserted

Answer 8

ultrasound to determine the location of CL, transfer embryo to uterine horn on the same side as the CL

Question 9

IVF definition

Answer 9

collecting unfertilized oocytes directly from uterus, fertilized in a lab, transferred to a recipient

Question 10

steps of IVF

Answer 10

-superovulation
-ovum pick up(OPU)
-grade oocytes
-in vitro maturation(oocyte maturation)
-in vitro fertilization
-culture embryos
-inseminate

Question 11

ovum pick up

Answer 11

transvaginal removal of oocytes by aspirating the follicles with aid of ultrasound

Question 12

what are oocytes being graded on for IVF

Answer 12

several intact layers of cumulus cells

Question 13

what stage do oocytes need to be matured to for IVF? how long does it take?

Answer 13

metaphase II, about 24 hours

Question 14

how long does it take between addition of sperm to oocytes to form embryos

Answer 14

8-20 hours

Question 15

what stage do embryos need to be cultured to for IVF? how long does it take?

Answer 15

morula or blastocyst phase, approximately 5 days

Question 16

what does ICSI stand for? what is it

Answer 16

intracytoplasmic sperm injection
single sperm injected directly into an oocyte

Question 17

benefit of ICSI

Answer 17

enables use of genetically valuable sperm that has poor motility, acrosomal or other defects

Question 18

what is gamete intrafallopian transfer(GIFT)

Answer 18

surgically transferring male and female gametes into the oviduct

Question 19

what is somatic cell nuclear transfer(SCNT)

Answer 19

create genetically identical animals (cloning)

Question 20

steps for SCNT

Answer 20

-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

Question 21

downsides of SCNT

Answer 21

-decreased genetic diversity
-expensive
-harder to prevent inbreeding
-more susceptible to loss from a single disease

Question 22

T/F SCNT always produces a clone that is physically or temperamentally identical

Answer 22

FALSE