4 research outputs found

    Optimal Timing for Oocyte Denudation and Intracytoplasmic Sperm Injection

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    Objectives. To analyze the impact of oocyte denudation and microinjection timings on intracytoplasmic sperm injection (ICSI) outcomes. Study Design. We included ICSI cycles with the following parameters: rank 1 or 2, female age <36 years, male factor infertility, long protocol using GnRH agonist and rFSH for ovarian stimulation, and use of freshly ejaculated sperm (=110). Several ICSI parameters were analyzed according to the time between oocyte retrieval and denudation (1) and the time between denudation and ICSI (2) using a statistical logistic regression analysis. Results. Neither 1 nor 2 had a significant influence on the Metaphase II (MII) rate but the fertilisation rate (FR) showed a significant improvement when 1 was longer (optimal results at 1=3 hours) while FR significantly decreased with the increase of 2. Optimal implantation (IR) and pregnancy (PR) rates were obtained when 1 was around 2 hours. Conclusion. Incubation of oocytes around 2 hours between retrieval and denudation may not increase MII rate but appears to lead to the optimal combination of FR and IR

    Le modèle de l’inactivation du chromosome X chez la souris

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    L’inactivation du chromosome X (ICX) constitue un excellent modèle d’étude de la mise en place de marques épigénétiques au cours du développement embryonnaire. C’est un processus essentiel chez les mammifères femelles car il permet la « compensation » du dosage des gènes liés à l’X entre les deux sexes. Chez la souris, l’inactivation de l’X survient en deux phases : l’une soumise à empreinte paternelle durant la période préimplantatoire ; l’autre aléatoire intervenant dans les cellules du futur embryon. Plusieurs résultats vont dans le sens d’une empreinte maternelle conférant au chromosome maternel une résistance à l’inactivation
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