Injection of antisense oligonucleotides was used to investigate the function of c-mos in murine oocytes. Oocytes injected with antisense c-mos oligonucleotides completed the first meiotic division but failed to initiate meiosis II. Instead, loss of c-mos function led to chromosome decondensation, reformation of a nucleus after meiosis I, and cleavage to two cells. Therefore, c-mos is required f...

With the technical assistance of Elva Ruiz A NUMBER of distinct functional stages can be recognized in the development of noiidifferentiated stem cells to mature red blood cells. Several investigators have attempted to design a model of this process based on studies of bone marrow morphology,”2 metabolism,1 mitotic activity4’5 and volumetric changes of the nuclei. 7 From these studies emerge a ...

  Background & Aim: Considering that antioxidants are known as effective free radicals scavenger, it may be able to improve the in vitro oocyte maturation and the fetal quality. This study was designed to determine the effect of Gundelia tournefortii leaves (GTE) hydro-alcoholic extract as a source of antioxidant on in vitro oocyte maturation. Experimental: Germinal vasicle (GV) were...

Spore formation in Bacillus subtilis involves a switch in the site of cell division from the midcell to a polar position. Both medial division and polar division are mediated in part by the actin-like, cytokinetic protein FtsA. We report the isolation of an FtsA mutant (FtsA(D265G)) that is defective in sporulation but is apparently unimpaired in vegetative growth. Sporulating cells of the muta...

BACKGROUND The importance of mitotic spindle checkpoint control has been well established during somatic cell divisions. The metaphase-to-anaphase transition takes place only when all sister chromatids have been properly attached to the bipolar spindle and are aligned at the metaphase plate. Failure of this checkpoint may lead to unequal separation of sister chromatids. On the contrary, the exi...

Organisms adapt their behavior and physiology to environmental conditions through processes of phenotypic plasticity. In one well-studied example, the division of labor among worker honey bees involves a stereotyped yet plastic pattern of behavioral and physiological maturation. Early in life, workers perform brood care and other in-hive tasks and have large internal nutrient stores; later in l...

We describe the vitellogenesis and oogenesis of Crepidostomum metoecus from Salmo trutta collected in Corsica. This is the first study conducted in the Allocreadiidae family. The maturation of C. metoecus vitellocytes comprises four different stages depending on organelle content. The follicular vitellarium is surrounded by a basal lamina. Vitellocytes are randomly distributed into the vitellar...

We present a mathematical model of granulocytopoiesis that depends on certain physiologically meaningful parameters. By choosing different values of these parameters, the model describes both the normal process and that in chronic myelogenous leukemia ((Ml,). The model fits all the available experimental data tested. Furthermore, it shows how the CML cells can ultimately outnumber the normal ce...