The purpose of the present study was to determine the chronology of the pre-implantation embryonic development in Myocastor coypus (coypu). It was carried out by daily colpocytological examination and controlled mating of 33 females. Oocytes and embryos were obtained by flushing from day 0 to day 10 post-coitus (p.c.). On day 1 p.c., oocytes predominated whereas on day 2 p.c. zygotes were predo...

The origin of the early embryonic loss that occurs during the first 4 days after mating in Californian doe-rabbits has been studied at 24 h or 60 h post coitum (p.c.). For comparison, 11 New Zealand doe-rabbits were slaughtered at the same times. The development stage of the embryo was determined after examination in toto at 24 h or by counting the morula nuclei at 60 h on histological sections...

The effect of modified vitrification was assessed on cellular development capability in mouse embryos cultured in vitro. In this study, 466 embryos (from zygote to morula stages) were vitrified then thawed embryos have been incubated for in vitro farther development up to blastocyst stage. Also, vitrification and thawing procedures were the same for all experimental groups. Mouse different embr...

Evaluation of quality and viability of bovine and rabbit preimplantation embryos following cryopreservation was the objective of this study. Bovine embryos of Holstein breed (n = 88) at the morula-early blastocyst stage (on the 7 day after the first insemination) and rabbit embryos (n = 135) from New Zealand breed at the morula stage (90–92 hpc) were cryopreserved by the two-step vitrification ...

Embryonic stem cells (ESCs) are useful for the study of embryonic development. However, since research on naturally conceived human embryos is limited, non-human primate (NHP) embryos and NHP ESCs represent an excellent alternative to the corresponding human entities. Though, ESC lines derived from naturally conceived NHP embryos are still very rare. Here, we report the generation and character...

Background: In somatic cell nuclear transfer (SCNT) method of cloning, transferred nucleus should be dedifferentiated from differentiated state to embryonic state. Molecular analysis showed that the reprogramming in the transferred nucleus was incomplete and cloned embryos have epigenetic abnormalities such as high DNA methylations levels. Since methylation in pre-implantation embryos has a cri...

Oocyte cumulus complexes were aspirated from 3 to 5 mm follicles of cows prestimulated with 2.000 IU PMSG 24 h before slaughter. Oocytes matured in culture were fertilized in vitro by heparinized freshly ejaculated or epididymal spermatozoa. The cultivation procedure for fertilized eggs was the same as that used for cultivation of oocytes. From 163 matured oocytes, 109 cleaved to the 2-cell sta...

Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule degradation and many other cellular functions. However, little is known about lysosomal function during early embryogenesis. Here, we found that the number of lysosomes increased after fertilization. Lysosomes were abundant during mouse preimplantation development until the morula stage, but their numbers de...

In the present study, we carried out a detailed light microscopy investigation of the cytochemical properties of the haemocytes of the colonial ascidian Botryllus schlosseri, using new cytochemical stains and enzymatic markers, a panel of antibodies and lectins as probes to characterise Botryllus blood cells further. Results indicate that lymphocyte-like cells are circulating undifferentiated c...