Offspring born from chimeras reconstructed from parthenogenetic and in vitro fertilized bovine embryos

Abstract

Chimeric embryos were produced by aggregation of parthenogenetic (Japanese Red breed) and in vitro fertilized (Holstein breed) bovine embryos at the Yamaguchi Research Station in Japan and by aggregation of parthenogenetic (Red Angus breed) and in vitro fertilized (Holstein breed) embryos at the St. Gabriel Research Station in Louisiana. After embryo reconstruction, live offspring were produced at each station from transplanting these embryos. The objective of this joint study was to evaluate the developmental capacity of reconstructed parthenogenetic and in vitro fertilized bovine embryos. In experiment I, chimeric embryos were constructed: by aggregation of four 8-cell (demi-embryo) parthenogenetic and four 8-cell stage (demi-embryo) IVF-derived blastomeres (method 1) and by aggregation of a whole parthenogenetic embryo (8-cell stage) and a whole IVF-derived embryo (8-cell stage) (method 2). Similarly in experiment II, chimeric embryos were constructed by aggregating IVF-derived blastomeres with parthenogenetic blastomeres. In this experiment, three categories of chimeric embryos with different parthenogenetic IVF-derived blastomere ratios (2:6; 4:4, and 6:2) were constructed from 8-cell stage bovine embryos. In experiment III, chimeric embryos composed of four 8-cell parthenogenetic and two 4-cell IVF-derived blastomeres or eight 16-cell parthenogenetic and four 8-cell IVF-derived blastomeres were constructed. Parthenogenetic demi-embryos were aggregated with sexed (male) IVF demi-embryos to produce chimeric blastocysts (experiment IV). In the blastocyst stage, hatching and hatched embryos were karyotyped. In experiment V, chimeric embryos that developed to blastocysts (zona-free) were cryopreserved in ethylene glycol (EG) plus trehalose (T) with different concentrations of polyvinylpyrrolidone (PVP; 5%, 7.5%, and 10%). In experiment I, the aggregation rate of the reconstructed demi-embryos cultured in vitro without agar embedding was significantly lower than with agar embedding (53% for 0% agar, 93% for 1% agar, and 95% for 1.2% agar, respectively). The aggregation was also lower when the aggregation resulted from a whole parthenogenetic and IVF-derived embryos cultured without agar than when cultured with agar (70% for 0% agar, 94% for 1% agar, and 93% for 1.2% agar, respectively). The development rate to blastocysts, however, was not different among the treatments. In experiment II, the developmental rates to the morula and blastocyst stages were 81%, 89%, and 28% for the chimeric embryos with parthenogenetic:IVF blastomere ratios of 2:6, 4:4, and 6:2, respectively. In experiment III, the developmental rate to the morula and blastocyst stages was 60% and 65% for the two 4-cell and four 8-cell chimeric embryos compared with 10% for intact 8-cell parthenogenetic embryos and 15% for intact 16-cell parthenogenetic embryos. To verify participation of parthenogenetic and the cells derived from the male IVF embryos in blastocyst formation, 51 embryos (hatching and hatched) were karyotyped, resulting in 27 embryos ...

Developmental competence of porcine parthenogenetic embryos relative to embryonic chromosomal abnormalities

“…Also there is a higher percentage of apoptosis in the haploid PA-embryos after Day 6 in culture, relative to IVF embryos, and there is a trend of an increased incidence of apoptosis during development in vitro . Boediono et al (1999) reported live chimeric calves born after the presumably diploid parthenotes were aggregated with fertilization-derived embryos; thus a possibility remains that with the proper sequence of oocyte activating stimuli, diploid parthenotes with a higher developmental potential can be obtained.…”

Generation and Characterization of Rabbit Embryonic Stem Cells

“…Nevertheless, parthenote-derived stem cells can contribute to research assessing the importance of imprinting gene expression in early development and to autologous cell-based therapy in the female. That some of the epigenetic abnormalities in parthenotes can be overcome was evidenced by the birth of parthenogenetic mice that were themselves reproductively normal [12][13][14][15]. Recent reports in with a nonhuman primate parthenote-derived stem cell line indicated that these cells could differentiated into tyrosine hydroxylase-positive dopaminergic neuronal phenotypes that were capable of long-term survival after engraftment into rat or monkey brains [16,17].…”

Oocyte genome cloning used in biparental bovine embryo reconstruction

“…Offspring produced with this technique were not identical to one another nor to their parents, as variability is given by the parental counterpart. Moreover, live o ffspring were obtained from chimeras reconstructed from aggregation of parthenogenetic and in vitro fertilized bovine embryos (Boediono et al ., 1999). In the rabbit, oviductal transfer of reconstructed zygotes resulted in 100% pregnancy on day 12, but no pregnancies were diagnosed on day 21 after ovulation (Escribá et al ., 2001).…”