[Detection of endogenous intracisternal type A particles in early mouse zygotes]. / Obnaruzhenie éndogennykh vnutritsisternal'nykh chastits tipa A v rannikh zigotakh myshi.

Electron microscopy was used to examine early zygotes from C57BL/6 mice aged 5-7 h after mating. A great number of intracisternal type A particles (IAP) in the cavity of smooth endoplasmic reticulum and in the large vesicles of the Golgi complex were demonstrated in ultrathin sections of any of the 70 embryos under examination. IAP were detected in different areas of zygote cytoplasm and near the vitelline membrane of the zygote. Expression of virus particles in so early zygotes provides evidence in favour of the hypothesis of IAP involvement in the processes of normal differentiation.

[Separate groups in the oocyte population of cows, their cytogenetic analysis and capacity for in vitro maturation]. / Otdel'nye gruppy v populiatsii ootsitov korov, ikh tsitogeneticheskii analiz i sposobnost' k sozrevaniiu in vitro.

Heterogenic population of the follicular oocytes of bovine ovaries has been divided into 5 groups on the basis of morphological characteristics. Chromatin structure, frequency of degenerative changes and the ability to maturation in vitro of different oocyte groups have been studied. The correlation of morphological characteristics of native oocytes and their ability to mature in vitro have been shown. The bovine follicular oocyte classification allows to pick out more homogeneous oocyte groups in comparison with the population as a whole and the oocyte group which is the best for maturation in vitro.

[Malate dehydrogenase isoenzyme induction in an Acetabularia chloroplast fraction with nuclear transplants]. / Induktsiia izozimov malatdegidrogenazy v khloroplastnoi fraktsii atsetabuliarii pri iadernykh transplantatsiiakh.

Changes in isozymes of malate dehydrogenase (MDH) in the chloroplast fraction under the transplantation of the A. crenulata nuclei in the A. mediterranea anuclear fragments were studied by means of electrophoresis in polyacrilamide gel. Within 30 days after the transplantation the nucleus induces in the chloroplast fraction MDH isozymes similar by the electrophoretic mobility with those of A. crenulata. The induction of such isozymes was observed both in the plants with the morphological characters of A. crenulata and the fragments which have not formed the reproductive caps, as well as under the transplantation of a small amount of cytoplasm from A. crenulata with chloroplasts in the anuclear fragments of A. mediterranea.