bioRxiv Science⌕ Search

Biology subjects

Domingo-Muelas, A.

Publications and source records attributed to Domingo-Muelas, A..

4 recordsLinked to original sources

Ultra-low oxygen tension during in vitro fertilization improves embryonic and adult outcomes in mice

Embryo culture, a required step during in vitro fertilization (IVF), exposes developing embryos to altered environmental conditions not normally experienced in vivo, including altered oxygen (O2) tension. Importantly, O2 influences gene expression, metabolism, and the activity of enzymes that sculpt the epigenetic landscape. The lowest O2 tension currently used in clinics during embryo culture is 5%, despite evidence that sections of the mammalian female reproductive tract have O2 levels as low at 2%. Lower O2 may therefore better mimic the in vivo environment and thus lead to improved pre- and postnatal outcomes in IVF-conceived offspring. Using our validated IVF mouse model, we show embryo culture at 2% O2 compared to culture under 5% O2 significantly improves embryo cell number, the chromatin landscape in preimplantation embryos, fetal and placental development during gestation, and metabolic function in adulthood. We further uncover mechanisms by which culture under ultra-low O2 mediates these improvements. Overall, these results suggest embryo culture with 2% O2 ameliorates adverse outcomes after IVF and provide evidence that IVF could be further improved by adjusting culture conditions to model the in vivo environment.

developmental biology↗

In Vitro Fertilization Accelerates Female Reproductive Aging Through Early Ovarian Failure

Reproductive aging is characterized by the progressive decline of reproductive function, with broad implications for overall health and longevity. Environmental factors, including assisted reproductive technologies (ART), can accelerate reproductive aging by promoting premature ovarian failure in females. In vitro fertilization (IVF), though widely used and generally considered safe, is associated with lasting effects on offspring health. Using a mouse model that closely approximates human IVF, we demonstrate that IVF accelerates reproductive aging in female offspring by inducing premature ovarian failure. IVF-conceived females exhibit altered ovarian function, disrupted endocrine profiles, and transcriptomic and epigenetic changes consistent with premature reproductive decline. These findings reveal long-term consequences of IVF on female reproductive health and highlight the need to understand how early-life interventions influence reproductive longevity.

developmental biology↗

Purinergic Receptor P2Y13 Controls Activation and Mode of Division in Subependymal Adult Neural Stem Cells

The subependymal zone (SEZ) of the mammalian brain is the most active germinal area that continues to generate newborn neurons throughout life. This area harbors a population of neural stem cells (NSCs) that can be found in different states of activation, each differing in proliferative capacity and molecular signature: quiescent NSCs (qNSCs), primed NSCs (pNSCs), and activated NSCs (aNSCs). There is currently a void in terms of the specific markers available to effectively discern between these transient states. Likewise, the molecular signaling mechanisms controlling the transition from quiescence to activation remain largely unexplored, as do the factors influencing the decision between differentiation and self-renewal during NSC division. Here, we present evidence that the metabotropic P2Y13 purinergic receptor plays a critical role in regulating adult neurogenesis. We found that P2Y13 is specifically expressed in NSCs within the adult SEZ and that its levels can be used to distinguish qNSCs from aNSCs. Functionally, P2Y13 signaling promotes NSC activation, enhancing lineage progression, while dampening their self-renewal capacity. Conversely, pharmacological blockade or genetic silencing of the P2Y13 receptor favors NSC quiescence. Thus, we identified the metabotropic P2Y13 purinergic receptor as a pivotal modulator of NSC dynamics, influencing both the balance between NSC quiescence and activation and the mode of NSC division at the subependymal zone.

neuroscience↗

The rates of adult neurogenesis and oligodendrogenesis are linked to cell cycle regulation through p27-dependent gene repression of SOX2

Cell differentiation involves profound changes in global gene expression that often have to occur in coordination with cell cycle exit. Because cyclin-dependent kinase inhibitor p27 reportedly regulates proliferation of neural progenitor cells in the subependymal neurogenic niche of the adult mouse brain, but can also have effects on gene expression, we decided to molecularly analyze its role in adult neurogenesis and oligodendrogenesis. At the cell level, we show that p27 restricts residual cyclin-dependent kinase activity after mitogen withdrawal to antagonize cycling, but it is not essential for cell cycle exit. Contrasting gene expression with chromatin accessibility, we find that p27 is coincidentally necessary to globally repress many genes involved in the transit from multipotentiality to differentiation, including those coding for neural progenitor transcription factors SOX2, OLIG2, and ASCL1. Our data reveal both direct association of p27 with regulatory sequences in the three genes and an additional hierarchical relationship where p27 repression of the Sox2 gene leads to reduced levels of SOX2-downstream targets Olig2 and Ascl1. In vivo, p27 is also required for the regulation of the proper level of SOX2 necessary for neuroblasts and oligodendroglial progenitor cells to timely exit cell cycle in a lineage-dependent manner.

neuroscience↗