Frozen preimplantation embryos: parental responsibility versus laboratory liability

Spatial Separation of Parental Genomes in Preimplantation Mouse Embryos

We have used two different experimental approaches to demonstrate topological separation of parental genomes in preimplantation mouse embryos: mouse eggs fertilized with 5-bromodeoxyuridine (BrdU)-labeled sperm followed by detection of BrdU in early diploid embryos, and differential heterochromatin staining in mouse interspecific hybrid embryos. Separation of chromatin according to parental ori...

One-step versus two-step culture of mouse preimplantation embryos.

BACKGROUND A comparison has been made of the development of mouse zygotes in either one-step or two-step culture systems. METHODS Embryo culture, blastocyst cell counts and embryo transfer were done. RESULTS No significant differences were observed in the proportions of blastocysts, rates of hatching, numbers of cells in the inner cell mass (ICM) and trophectoderm (TE) that developed in pro...

Steroidogenesis in rabbit preimplantation embryos.

Rabbit preimplantation embryos were flushed from the reproductive tract at 24 hr (1- to 2-cell stage), 48 hr (morula), 72 hr (morula), 96 hr (blastocyst), 120 hr (blastocyst), and 144 hr (blastocyst) post coitum. At 168 hr (early postimplantation period), gestation sacs were excised, frozen, and sectioned in a cryostat. Delta5-3beta-Hydroxysteroid dehydrogenase [3(or 17)beta-hydroxysteroid:NAD(...

P-42: Who Owns the Frozen Embryos?

Background: Success in assisted reproductive techniques is raising hope for many infertile couples, but as in these techniques many embryos are made, there is no choice other than cryopreservation of the not-transferred embryos. Along with development of these techniques, the number of In-vitro made embryos is rising and the number of transferred embryos is decreasing to prevent multiple gestat...

Genetic decision-making: parental responsibility.