IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Molecular mechanism of cortical reaction in mouse oocytes
Autor/es:
DE PAOLA, M. MATILDE; MICHAUT, MARCELA A.
Lugar:
Dubai
Reunión:
Congreso; Energy, Materials and Nanotechnology (EMN) meeting on membranes; 2016
Institución organizadora:
Open-Access House of Science and Technology
Resumen:
Cortical reaction is a calcium-regulated secretion that represents a membrane fusion process essential for fertilization. Following sperm fusion, cortical granules (CG) undergo exocytosis to release their content into the perivitelline space. The secretion diffuses into the zona pellucida and transforms it into a physical barrier, avoiding polyspermy and ensuring normal embryonic development. The molecular mechanism of membrane fusion during cortical reaction is still poorly understood and is thought to be mediated by the SNARE (SNAP receptors) pathway. SNAPs proteins act as an adaptor protein that physically links SNAREs to NSF, thereby mediating disassembly and recycling of SNARE complexes. We demonstrated for the first time the presence of αSNAP and NSF in mammalian oocytes, using RT-PCR, WB and IFI techniques in mice model. To evaluate the function of these proteins in cortical reaction, we set up a functional assay based on the quantification of cortical granules metaphase II oocytes activated parthenogenetically with strontium. We showed that αSNAP/NSF complex is necessary for CG exocytosis since microinjection of specific antibodies inhibits this process and proposed a model working for αSNAP and NSF in cortical reaction in mouse eggs (Fig. 1). To further understand the role of αSNAP in female fertility, we used a spontaneous mutant mouse model for αSNAP known as hyh (hydrocephalus with hop gait), carrying a point mutation M105I. Due to αSNAP knockout mice die at embryonic stages, the hyh mouse is a unique in vivo model to explore the αSNAP function. We found that hyh female mice exhibit strongly reduced fertility parameters and that M105I mutation in αSNAP leads to multifactorial fertility defects in this mouse strain. These data demonstrate that αSNAP and NSF play an important role in female reproduction.