Y‑27632 is a specific inhibitor of Rho‑associated protein kinases (ROCKs), which are downstream effectors of Rho GTPase. The present study aimed to determine the effect of the specific ROCK inhibitor, Y‑27632, on fresh human embryos and on single blastomeres obtained from discarded human embryos. A total of 784 poor‑quality embryos were included, of which 526 were allocated to blastocyst cultur...

Dorsal or ventral blastomeres of the 16- and 32-cell stage animal hemisphere were labeled with a lineage dye and transplanted into the position of a ventral, vegetal midline blastomere. The donor blastomeres normally give rise to substantial amounts of head structures and central nervous system, whereas the blastomere which they replaced normally gives rise to trunk mesoderm and endoderm. The c...

Newly-formed pairs of 16-cell blastomeres were collected by periodic observation of isolated 8-cell blastomeres. Any pairs formed by division were recovered and classified as being composed of 1/16 blastomeres that differed in size or were of similar size. All of the latter and some of the former were then cultured for periods of up to 20h. The remaining pairs of different-sized blastomeres wer...

Blastomeres of the early mouse embryo are thought to be equivalent in their developmental properties at least until the eight-cell stage. However, the experiments that have led to this conclusion could not have taken into account either the spatial origin of individual blastomeres or the spatial allocation and fate of their progeny. We have therefore readdressed this issue having defined cell l...

To determine the critical cell numbers needed to form blastocyst stage embroys, bisected mouse embryos of 8-cell stage and compacted morula (approximately 16 cells) containing different numbers of blastomeres were cultured in vitro. The percentage of bisected compacted morulae with 7-9 blastomeres that developed to eu-blastocysts was 98.8%, while only 64.2% of the bisected 8-cell embryos with 4...

Dorsal or ventral blastomeres of the 16and 32-cell stage animal hemisphere were labeled with a lineage dye and transplanted into the position of a ventral, vegetal midline biastomere. The donor blastomeres normally give rise to substantial amounts of head structures and central nervous system, whereas the biastomere which they replaced normally gives rise to trunk mesoderm and endoderm. The clo...

Treatment of Xenopus animal pole tissue with activin results in the induction of mesodermal cell types and a dramatic elongation of the tissue. The morphogenetic movements involved in the elongation appear similar to those in normal gastrulation, which is driven by cell rearrangement and cell intercalations. We have used this system to explore the potential regulation of cell-cell adhesion and ...

The present study examined the influence of post-cleavage time of nuclear donors on the development of reconstituted embryos in bovine nuclear transfer. Blastomeres of 16-cell stage embryos derived from in vitro-maturation, fertilization and culture were used as nuclear donor source. They were treated with 10 microM nocodazole for 12 hr. Blastomeres that cleaved within 3 hr after the removal of...

The aim of the present study was to establish a reliable procedure with nocodazole treatment for the synchronous cleavage of blastomeres of bovine embryos used as nuclear donors for nuclear transfer. Sixteen-cell stage embryos derived from in vitro-maturation, fertilization and culture were used. In three initial experiments, embryos were incubated in mTCM-199+FCS with various concentrations (0...