nuclear Transfer

t or f’

Every oocyte is several months older than the individual with the ovary

t

in terms of nuclear againg for the oocyte, the DNA is exposed to potential damage through life, this cna cause —

aneuploidy (but sperm aging is not as much of a thing)

in terms of cytoplasmic aging, what is the main thing we tall about?

mitochondria

what happens to the mitochondria in the oocyte as age?

Changes in where the mito are distributed in the egg, changes in the number and shape

 

• distribution

• number

• shape

in humans (so, not lipid droplets), what is the other thing we may care about in terms of cytoplasmic aging?

cortical granules may change with age

are good or bad quality mitochondria hooded?

good quality

good vs bad quality mito: light vs dense matrix

good: light

bad: dense matrix

what is the distibituion of mitochondria in good vs poor quality?

good: even

poor: peripheral

when there are poor quality mitochondria, are they high or low in numbers?

low

for cortical granules, describe distribution for good vs poor

good: peripheral

bad: clustered, even

theoretical Options for Compensation for old oocyte

• Put old nucleus into younger oocyte cytoplasm

• Cytoplasmic supplementation (numerous organelles):

• mitochondria supplementation only

for autologous mitochondrial transfer, the ethical issue was not the fact that the DNA was different, it was:

the scientific community believed that the belief in younger cells in the cortex having better mitochodnria was unfounded

List challenges with mitochondrial spindle transfer/ general idea of nuclear trasnfer for aging oocytes

• requires 2 sets of oocytes (donor), logistically tricky perhaps

• some tissue will not get used, (ethical)

• pronuclei transfer requires planned fertilization (ethical)

• isolation of spindle is tricky

• if not spindle, then GV which then needs IVM

list challenges with cloning

• oocyte needs to be able to reset the donor nucleus

• need donor (could be tricky, also ethically illegal in canada)

• adult somatic cells are less easily reporgrammed than embryonic cells

• cloning for infertility feels insane

• cloning for therapuetic purposes seems good but requires sacrifice of a blastocyst perhaps

• Dolly did not live as long