Repository logo

Browsing by Author "Zambelli, Filippo"

Now showing 1 - 2 of 2
  • Human oocyte meiotic maturation is associated with a specific profile of alternatively spliced transcript isoforms
    Publication . Cornet‐Bartolomé, David; Barragán, Montserrat; Zambelli, Filippo; Ferrer‐Vaquer, Anna; Tiscornia, Gustavo; Balcells, Susanna; Rodriguez, Amelia; Grinberg, Daniel; Vassena, Rita
    The transition from a transcriptionally active state (GV) to a transcriptionally inactive state (mature MII oocytes) is required for the acquisition of oocyte developmental competence. We hypothesize that the expression of specific genes at the in vivo matured (MII) stage could be modulated by posttranscriptional mechanisms, particularly regulation of alternative splicing (AS). In this study, we examined the transcriptional activity of GV oocytes after ovarian stimulation followed by oocyte pick-up and the landscape of alternatively spliced isoforms in human MII oocytes. Individual oocytes were processed and analyzed for transcriptional activity (GV), gene expression (GV and MII), and AS signatures (GV and MII) on HTA 2.0 microarrays. Samples were grouped according to maturation stage, and then subgrouped according to women's age and antral follicular count (AFC); array results were validated by quantitative polymerase chain reaction. Differentially expressed genes between GV and MII oocytes clustered mainly in biological processes related to mitochondrial metabolism. Interestingly, 16 genes that were related to the regulation of transcription and mitochondrial translation showed differences in alternatively spliced isoform profiles despite not being differentially expressed between groups. Altogether, our results contribute to our understanding of the role of AS in oocyte developmental competence acquisition.
    2021Journal article Restricted access Show more
  • Trophoblast attachment to the endometrial epithelium elicits compartment-specific transcriptional waves in an in-vitro model
    Publication . Vergaro, Paula; Tiscornia, Gustavo; Zambelli, Filippo; Rodríguez, Amelia; Santaló, Josep; Vassena, Rita
    Implantation is a major bottleneck in human reproduction (Polanski et al., 2014). The average implantation rate for an embryo ranges from 30% to 40% (Coughlan et al., 2014). Recurrent implantation failure (RIF) is estimated to occur in approximately 4% of IVF cycles (Koot et al., 2012), although estimates vary because there are several somewhat different definitions of RIF in the literature. Implantation of the blastocyst in the receptive endometrium is a sequential process involving apposition, attachment and invasion that precedes the establishment of pregnancy (Wang and Dey, 2006). Successful implantation requires embryo competence and endometrial receptivity, both of which are dynamic and highly regulated states (Wang and Dey, 2006). In addition to genetic disorders (which are a major cause of implantation failure and miscarriage), embryo competence, quality and ultimately developmental potential depend on the embryo achieving the correct regulatory, signalling and metabolic states (Fu et al., 2009; Hourvitz et al., 2006; Lundin et al., 2001; Simon and Laufer, 2012; Sjoblom et al., 2006). A key determinant of these embryonic states is their underlying transcriptional dynamics; for instance, waves of embryonic transcriptional activation direct early development and the symmetry breaking needed for cell fate specification (Shi et al., 2015; Vassena et al., 2011).
    2021-01Journal article Open access Show more