Assisted reproductive technologies

Question 1

what happens in cytoplasmic transfer?

Answer 1

ooplasm added to egg- results in increase of mtDNA genomes so fertile

Question 2

what are the two methods for mt replacement?

Answer 2

spindle transfer and pronuclear transfer

Question 3

what happens in spindle transfer

Answer 3

eggs are arrested at metaphase I before fertilisation so chromosomes aligned on spindle, spindle removed from donor and spindle from patient egg and added to donor egg, egg fertilised by ICSI, cleaving embryo transferred to uterus

Question 4

what is an issue with spindle transfer?

Answer 4

mt cluster around spindle so may get transfer of diseased mt to oocyte

Question 5

what happens during pronuclear transfer?

Answer 5

both patient and donor eggs are fertilised, pronuclei removed from donor egg. pronuclei transferred from patient to empty donor egg, embyro allowed to develop and cleaving embryo removed and implanted into uterus

Question 6

why is mt replacement more risky in females?

Answer 6

mutated genomes may be preferentially replicated and may get more mutated genomes in subsequent generations- inherited maternally

Question 7

contributions of up to 63% in embryos results from somatic cell nuclear transfer, why?

Answer 7

preferential replication of mtDNA

Question 8

less likely to get preferential replication if two species are what?

Answer 8

more similar

Question 9

what could you do to deplete mtDNA in donor cells?

Answer 9

artifically treat them

Question 10

donor mtDNA are what in some intraspecific crosses?

Answer 10

absent, but persistence is variable