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Perez-Palacios, R.

Publications and source records attributed to Perez-Palacios, R..

2 recordsLinked to original sources

Assessing the influence of distinct IVF culture media on human pre-implantation development using single-embryo transcriptomics

The use of Assisted Reproductive Technologies (ART) is consistently rising across the world. However, making an informed choice on which embryo culture medium should be preferred to ensure satisfactory pregnancy rates and the health of future children critically lacks scientific background. Particularly, embryos within their first days of development are highly sensitive to their micro-environment. Here, we aimed to determine the impact of culture media composition on gene expression of human preimplantation embryos. By employing single-embryo RNA-sequencing after 2 or 5 days of post-fertilization culture in different commercially available media, we revealed medium-specific differences in gene expression changes. In particular, we found that culture medium composition can affect the dynamics of expression of developmentally relevant genes at day-2 but the differences were mitigated at the blastocyst stage. This study highlights the ability of embryos conceived in suboptimal in vitro culture media to recover proper transcriptome competency.

developmental biology↗

GPIF constrains Polycomb Repressive Complex 2 activity in germ cells

The Polycomb machinery is required for the proper orchestration of gene expression by virtue of its critical role in maintaining transcriptional silencing. It is composed of several chromatin modifying complexes, including Polycomb Repressive Complex 2 (PRC2), which deposits H3K27me2/3. Here, we report the identification of a new cofactor of PRC2, EZHIP (EZH1/2 Inhibitory Protein), expressed predominantly in the gonads. EZHIP limits the enzymatic activity of PRC2 and lessens the interaction between the core complex and its accessory subunits, but does not interfere with PRC2 recruitment to chromatin. Deletion of Ezhip leads to a global increase in H3K27me2/3 deposition both during spermatogenesis and at late stages of oocyte maturation. This alteration of the epigenetic content of mature oocytes does not affect the initial number of follicles but is associated with a reduction of follicles in aging mice. We provide evidences that mature oocytes Ezhip -/- are not fully functional and that fertility is strongly impaired in Ezhip -/- females. Altogether, our study uncovers EZHIP as a novel functional player in the comprehensive chromatin remodeling that occurs in the gonads.

developmental biology↗