Distinct requirements for PI3K isoforms p110α and p110δ for PIP3 synthesis in mouse oocytes and early embryos.

The PI3K/Akt pathway is thought to regulate key steps of mammalian oogenesis, such as dormant oocyte awakening during follicular activation, meiotic resumption and oocyte maturation. Supporting evidence is however indirect, as oocyte PI3K activation has never been formally demonstrated, and the PI3K isoforms involved have not been revealed. Here, we employed fluorescent PIP3 biosensors to characterize PI3K dynamics in mouse oocytes and we investigated the contribution of PI3K isoform p110α via conditional genetic ablation.

In silico and in vitro metabolism studies of the new synthetic opiate AP-237 (bucinnazine) using bioinformatics tools.

The recent emergence of new synthetic opioids (NSOs) compounds in the illicit market is increasingly related to fatal cases. Identification and medical care of NSO intoxication cases are challenging, particularly due to high frequency of new products and extensive metabolism. As the study of NSO metabolism is crucial for the identification of these drugs in cases of intoxication, we aimed to investigate the metabolism of the piperazine NSO AP-237 (= bucinnazine).

Identification, synthesis and quantification of eutylone consumption markers in a chemsex context.

Eutylone is a cathinone-derived synthetic amphetamine scheduled by the World Health Organization and European Monitoring Centre for Drugs and Drug Addiction since 2022 due to its growing consumption. We report here an eutylone intoxication involving a 38-year-old man and a 29-year-old woman in a chemsex context. A bag containing a white crystalline powder labelled as a research product was found in their vehicle.

MRCK activates mouse oocyte myosin II for spindle rotation and male pronucleus centration.

Asymmetric meiotic divisions in oocytes rely on spindle positioning in close vicinity to the cortex. In metaphase II mouse oocytes, eccentric spindle positioning triggers cortical polarization, including the build-up of an actin cap surrounded by a ring of activated myosin II. While the role of the actin cap in promoting polar body formation is established, ring myosin II activation mechanisms and functions have remained elusive.