but it still needs a bit of work

but it still needs a bit of work

jc@embryos.net Reprogenetics ART Institute of Washington Life Global Principle investigator of cytoplasmic transfer series (1996-2001)

Is there an alternative to MRT? Lessons from the cytoplasmic transfer series Cellular stress from micromanipulation? (safety) Preferred technical approach (MST, PNT, PBT)? Nomenclature?

YES Preimplantation Genetic Diagnosis or PGD (PGD for mitochondrial disease) Use of PGD varies from 3-85% (USA data) Usage in Europe mostly limited to early embryo stages (.) Blastocyst culture increases success rates Allows biopsy of a better sample Cryopreservation survival higher with blastocysts Evidence shows PGS is successful at blastocyst

Less than 50 cases of PGD for Mito Disease About a dozen papers (using pb or blastomere biopsy) Shows reliability increases with cell and egg number Shows little variation in mutation load PGD for mito disease should be considered at blastocyst stage in combination with vitrification

Sallevelt et al, 2013

Mid-90s state of assisted reproduction Acceptable pregnancy rates achieved by multiple embryo transfer Early knowledge about embryonic aneuploidy and age Cytoplasmic failure seemed a reasonable proposition Selected patients with multiple failed IVF, poor embryo development but. NOT increased maternal age Three patient cycles using electro-fusion of cytoplasts Increased abnormal fertilization (same as MRT work) Changed technology to cytoplasmic transfer by injection Based on ICSI for male factor (>50,000 babies) Cohen et al, 1997 and 1998

Cohen et al, 1998

37 cycles (33 patients) 17 babies born 12 deliveries 1 early XO miscarriage 1 late XO termination One male twin at 18 months borderline PDD-NOS Two babies confirmed with donor mitochondria in a series of n=8 Heteroplasmy First phase follow-up study 2014-2015 Preliminary data is reassuring Cohen et al, 1997, 1998, 1999; Brenner et al 2000, Barritt et al, 2001

Two types of experiments Using combinations of two inbred species: heteroplasmic mice are developmentally affected (minor to major) Using inter-strain and F1 hybrids: (no effect or minor) Inbred - At least 20 consecutive generations of sibling or parent/offspring mating Inbred mice are homozygous at virtually all of their loci We are not an inbred species Acton et al, 2007 Liang et al, 2009 - Cheng et al, 2009 We find that inter-strain mpnt, ST, and ooplasm transfer produce little or no long-term adverse effects on growth rate or methylation states of the genes assayed.

Seen after all forms of manipulation But can be minor (ICSI) Cytoplasmic transfer (CT) similar to ICSI CT pilot study using ICSI (>50,000 ICSI babies in 1996) Electrofusion - no prior alternative (0 babies) Sendai Virus Extract (SeV) (0 babies) Membrane relaxants (0 babies)

Two implantations with XO after CT Possibly significant Possibly related to cellular stress (XO can occur during formation of pb2) Strongly recommend PGS after MRT to confirm normal chromosome set

Polar body transfer (PBT) was successfully used to model MRT in the mouse (Wang et al, 2014) Highly successful in the mouse In some mouse strains polar bodies are sometimes viable (.) In the human they are very different from patient to patient

Changing genes which are passed on to future generations or changing genes in gametes and very early embryos [meaning not temporarily as in altered gene expression but changing the code]. Maybe but the altered genes already existed in someone else. It is the combination of ndna and mtdna that is novel, but that descriptive is similar to each new fertilization.

Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow treatment of a disorder by inserting a gene into a patient's cells instead of using drugs or surgery. Yes, very close, maybe a specialized form? - Gene therapy is an experimental technique that uses someone else s genes to treat or prevent disease. Applies to MRT. Does it apply to CT?.

or Genetic Engineering. Genetic engineering is the process of manually adding new DNA to an organism. The goal is to add one or more new traits that are not already found in that organism. This probably does not apply. No likely addition of new traits. Addition of new traits is not the goal.

jc@embryos.net