Asunto(s)
Antimaláricos/administración & dosificación , Artemisia annua , Malaria Falciparum/diagnóstico , Extractos Vegetales/administración & dosificación , Adolescente , Adulto , Anciano , Femenino , Francia , Humanos , Malaria Falciparum/prevención & control , Masculino , Persona de Mediana Edad , Viaje , Insuficiencia del Tratamiento , Adulto JovenRESUMEN
The dynamics of the subcellular distribution of PLCbeta1 was investigated during meiosis competence acquisition and meiosis resumption in relation to oocyte diameter and to nonsurrounded-nucleolus or surrounded-nucleolus chromatin configurations. Oocytes collected after both in vivo and in vitro folliculogenesis were studied. In both conditions, at the beginning of the process, most oocytes exhibited a nuclear PLCbeta 1 associated with a nonsurrounded-nucleolus chromatin configuration. Then at the final stage of the process, the factors shifted mainly toward a cytoplasmic PLCbeta1 and a surrounded-nucleolus chromatin configuration, typical of a preovulatory fertilizable oocyte. Additionally, only germinal vesicle oocytes with a diameter > 75 microm, and exhibiting cytoplasmic PLC beta1 distribution and surrounded-nucleolus chromatin configuration, resumed meiosis. Our findings demonstrate a strong correlation between oocyte diameter, chromatin configuration, and PLCbeta1 localization. Thus, PLCbeta1 localization appears to be a key factor determining the progressive acquisition of meiotic competence and final resumption of meiosis.
Asunto(s)
Meiosis/fisiología , Oocitos/citología , Oocitos/fisiología , Oogénesis/fisiología , Folículo Ovárico/fisiología , Fosfolipasa C beta/fisiología , Animales , Diferenciación Celular/fisiología , Células Cultivadas , Femenino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Oocitos/enzimología , Folículo Ovárico/citología , Folículo Ovárico/enzimología , EmbarazoRESUMEN
As highlighted in this review, the phosphoinositide-phospholipase C pathway is strongly implicated in the control of mouse oocyte meiosis. The pathway becomes progressively functional as oocyte growth advances, and it appears to play a role in the G2/M transition when meiosis resumes, at least in the in vitro spontaneous model. Even if the inositol 1,4,5-trisphosphate receptors are present from the beginning, they function and release Ca2+ when the follicular antrum appears. Phospholipase C beta1 (PLC beta 1) is first exclusively localized to the nucleus and then migrates to the cytoplasm when the oocyte is fully grown. During oocyte maturation PLC beta 1 is active in the cytoplasm before it migrates and becomes active in the nucleus just prior to germinal vesicle breakdown. Because a similar circuit is observed for protein kinase C alpha (PKC alpha), PKC beta 1, PKC beta 2, and active mitogen-activated protein kinase, it is tempting to envisage that a feedback loop occurs between these pathways as demonstrated in other cell types. The chronology of these molecular movements into the oocyte reveals the particular and important role of the nucleus phosphoinositide cycle during oocyte meiosis. It appears also that this chronology is crucial and that defects leading to an inappropriate intracellular localization can have dramatic consequences. Such anomalies can prevent the production of competent oocytes and lead to fertility problems.