During vertebrate egg maturation, cytokinesis initiates after one pole of the bipolar metaphase I spindle attaches to the oocyte cortex, resulting in the formation of a polar body and the mature egg. It is not known what signal couples the spindle pole positioning to polar body formation. We approached this question by drawing an analogy to mitotic exit in budding yeast, as asymmetric spindle a...

Knowledge about the mechanism that establishes embryonic polarity is fundamental in understanding mammalian development. In re-addressing several controversial claims, we recently proposed a model in which mouse embryonic polarity is not specified until the blastocyst stage. Before fertilization, the fully differentiated oocyte has been characterized as "polarized," and we indeed observed that ...

Intracellular calcium transients are a universal phenomenon at fertilization and are required for egg activation, but the exact role of Ca2+ in second-polar-body emission remains unknown. On the other hand, similar calcium transients have not been demonstrated during oocyte maturation, and yet, manipulating intracellular calcium levels interferes with first-polar-body emission in mice and frogs...

AIM To calibrate eight-polar bioelectrical impedance analysis (BIA) against dual-energy X-ray absorptiometry (DXA) for the assessment of total and appendicular body composition in healthy adults. RESEARCH DESIGN A cross-sectional study was carried out. SUBJECTS Sixty-eight females and 42 males aged 21-82 years participated in the study. METHODS Whole-body fat-free mass (FFM) and appendicu...

Background: In this study we evaluate the effects of different doses of GDF9 with fixed dose of BMP15 on quality of in vitro maturated sheep oocytes. Materials and Methods: Good ovine Cumulus-oocyte complexes (COCs) were first transferred to Pre-IVM medium, and then to three IVM mediums supplemented with 10%v/v BMP15 and: 1) 175 ng/ml 2) 131 ng/ml or 3) 219 ng/ml GDF9. After maturation period, ...

Most studies on preconception diagnosis published so far have used polymerase chain reaction (PCR) analysis to identify single gene defects. Although fluorescent DNA probes have been used to obtain a partial cytogenetic diagnosis of aneuploidies in first polar bodies without defined chromosome structures, the analysis of structural chromosome anomalies in the interphase nucleus is not adequate....

Two new species of Henneguya (Myxozoa) were described from specimens collected on the gills of Hoplosternum littorale (Hancock, 1828) (Callichthyidae) and Cyphocharax gilbert (Quoy and Gaimard, 1824) (Curimatidae), from Guandu River, State of Rio de Janeiro, Brazil. The species described were compared with the related species of the genus. The new species of Henneguya parasitic on H. littorale ...