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...

2- to 4-cell and morula- to blastocyst-stage mouse embryos were cultured for 1 h in tritiated leucine at two specific activities and their subsequent development followed in vitro and in vivo (after transfer to recipients), respectively. 2- to 4-cell embryos that incorporated an average of 42 d.p.m. per embryo were impaired in their ability to develop to the morula and blastocyst stage. Recipie...

Ultrastructures of circulating hemocytes were studied in 9 botryllid ascidians. The hemocytes are classified into five types: hemoblasts, phagocytes, granulocytes, morula cells, and pigment cells. These five types are always found in the 9 species. They should represent the major hemocyte types of the circulating cells in the blood. Hemoblasts are small hemocytes having a high nucleus/cytoplasm...