1,721,004 research outputs found
The subcortical maternal complex: multiple functions for one biological structure?
No full textThe subcortical maternal complex (SCMC) is a multiprotein complex uniquely expressed in mammalian oocytes and early embryos, essential for zygote progression beyond the first embryonic cell divisions. Similiar to other factors encoded by maternal effect genes, the physiological role of SCMC remains unclear, although recent evidence has provided important molecular insights into different possible functions. Its potential involvement in human fertility is attracting increasing attention; however, the complete story is far from being told. The present mini review provides an overview of recent findings related to the SCMC and discusses its potential physiological role/s with the aim of inspiring new directions for future research
Safety in Assisted Reproductive Technologies: Insights from Gene Expression Studies During Preimplantation Development
No full textCustom microarray analysis of gene expression of ovine oocytes subjected to vitrification
No full textEvaluating the Response to Cryopreservation of Ovine Fibroblast Spheroids
No full textCell spheroids are widely studied for their potential applications in tissue engineering and regenerative medicine. The present work investigated the effects of cryopreservation on spheroids derived from ovine fibroblasts, depending on spheroid size (140 or 220 µm). Specifically, it explored how cryopreservation impacted several biological and physical parameters including cell damage, viability, metabolism, adhesion, proliferation, and spheroid mass density, weight, and diameter at three time points after thawing. A Live/Dead assay provided a visual assessment of cell damage, cell viability and metabolic activity were assessed by an Alamar Blue assay, and a replating assay evaluated cell adhesion and proliferation capabilities. Spheroid mass density, weight, and diameter were quantified by the W8 Biophysical Analyzer, creating accurate biophysical profiles. Real-time PCR (RT-PCR) analysis was employed to uncover gene expression changes following cryopreservation. Our findings indicate that spheroids measuring 140 µm in diameter largely maintained their biophysical features and cell viability post-cryopreservation, whereas those at 220 µm exhibited a decline in both vitality and mass density. The reduced vitality of 220 µm spheroids likely reflects size-related limitations in cryoprotectant diffusion and stress within the core. Overall, this study provides a comprehensive understanding of how cryopreservation affects ovine fibroblast spheroid biophysics and cellular integrity, laying the groundwork for improved preservation techniques for cell spheroids
Expression pattern of the sub-cortical maternal complex in ovine oocytes and pre-implantation embryos
No full textThe emerging role of the oocyte cortical domain in maturation, fertilization, and development
No full textThe cell cortex, a cytoskeletal network with regulatory signalling pathways, is localized beneath the cell membrane: it is especially prominent in mammalian oocytes. As in other cells, the cortex ensures appropriate shape and robustness of oocytes. It is also involved in other key and more specific functions. The cortex is part of the interface between the germinal and somatic cell compartments; as such, it participates in the delicate bi-directional interaction by which oocytes regulate cumulus cell function and in return, oocytes receive nutrients and regulative factors from cumulus cells. During oocyte maturation, fertilization, and early development, the cortex undergoes major structural and functional modifications. Such changes are needed to support crucial processes, including meiotic spindle localization, polar body extrusion, chromosome segregation, and pronuclear formation. Cortex dysregulation may be also implicated in blastomere fragmentation during early embryo development. Mechanical properties of the cortex are associated with oocyte quality and developmental competence; with appropriate technology, such properties could be harnessed to develop new approaches to non-invasive oocyte assessment in human IVF
Unveiling mRNA changes during meiotic progression and pre-implantation development: help from large animal models.
No full text"Assisted reproductive technologies (ART) are successfully applied in several mammals, including humans, thanks to the ability of oocytes and embryos to face maturation, fertilization and first development in vitro. However, efficiency and safety of ART represent main issues. Mammalian oocytes and early embryos are transcriptionally inactive, and rely exclusively on maternal RNAs and proteins, deposited during oocyte growth, until embryonic genome activation (EGA). Such transcriptional quiescence needs complex post-transcriptional and post-translational mechanisms to coordinate meiotic maturation, fertilization, and reprogramming of the nascent genome. These events are the final outcome of complex, hormonally regulated biological processes that translate into specific molecular mechanisms, which are still far from being fully understood. A deep knowledge of these early phases of development is crucial to understand the core mechanisms of life onset, and to optimize the safety and efficiency of in vitro reproductive technologies. This work focuses on meiotic progression and pre-implantation development in mammals, underlining the importance of fundamental molecules stored during oocyte growth and selectively used during early embryogenic stages. Taking into account the species-specific behaviour of these pivotal molecules, this review describes the advantages of using large domestic animals for research in the reproductive field and proposes large domestic animals as models to improve human ART
High hydrostatic pressure treatment improves the quality of in vitro-produced ovine blastocysts
No full textMicroplastic exposure induces epithelial barrier alterations and increases collagen deposition in a 3D human endometrial model in vitro
No full textPurpose: To investigate the effects of microplastics (MPs) on the human endometrium in vitro. Methods: A predictive 3D endometrial in vitro model was generated using highly porous scaffolds where human endometrial stromal (hESC) and epithelial (hEEC) cells were co-cultured for 35 days. The newly generated endometrial barrier was then exposed to different MP concentrations (from 0.25 to 50 mg/ml) for 24 h and 48 h, respectively. Histological staining and functional analyses were performed to assess the endometrial barrier integrity. Molecular studies and collagen deposition were evaluated to investigate the possible activation of pro-apoptotic and pro-fibrotic related pathways. Results: MP exposure for 24 h does not affect endometrial barrier integrity nor collagen synthesis and deposition. Similar responses are detected when concentrations between 0.25 and 1 mg/ml are used for 48 h. In contrast, 48-h incubations with higher doses (10–50 mg/ml MPs) induce epithelial barrier alterations, reduce TEER values and decrease ZO1 and CDH1 gene transcription. This is accompanied by the activation of pro-fibrotic signalling pathways resulting in collagen increment, which often accompanies endometriosis-related alterations. Conclusion: The data obtained suggest MP ability to exert deleterious effects in vitro on human endometrium, with a possible negative impact on its functionality and receptivity
The effect of phytoemagglutinin on in vitro embryo development of ovine prepubertal oocytes.
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