Warif El Yakoubi

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Neural stem cell research suffers from a lack of molecular markers to specifically assess stem or progenitor cell properties. The organization of the Xenopus ciliary marginal zone (CMZ) in the retina allows the spatial distinction of these two cell types: stem cells are confined to the most peripheral region, while progenitors are more central. Despite this(More)
In multicellular organisms the fusion of two gametes with a haploid set of chromosomes leads to the formation of the zygote, the first cell of the embryo. Accurate execution of the meiotic cell division to generate a female and a male gamete is required for the generation of healthy offspring harboring the correct number of chromosomes. Unfortunately,(More)
A key feature of meiosis is the step-wise removal of cohesin, the protein complex holding sister chromatids together, first from arms in meiosis I and then from the centromere region in meiosis II. Centromeric cohesin is protected by Sgo2 from Separase-mediated cleavage, in order to maintain sister chromatids together until their separation in meiosis II.(More)
Cell division with partitioning of the genetic material should take place only when paired chromosomes named bivalents (meiosis I) or sister chromatids (mitosis and meiosis II) are correctly attached to the bipolar spindle in a tension-generating manner. For this to happen, the spindle assembly checkpoint (SAC) checks whether unattached kinetochores are(More)
Ten years have now passed since the discovery of quiescent neural stem cells within the mammalian retina. Beside the fascinating aspect of stem cell biology in basic science, these cells have also offered hope for the treatment of incurable retinal diseases. The field has thus rapidly evolved, fluctuating between major advances and recurring doubts. In this(More)
BrdU is a thymidine analog that is incorporated into DNA during the S-phase of the cell cycle. BrdU incorporation can be used to quantify the number of cells that are in S-phase in the time period that BrdU is available. Thus, BrdU incorporation is an essential method in the quantitative analysis of cell proliferation, during normal embryonic development or(More)
The retina of fish and amphibian contains genuine neural stem cells located at the most peripheral edge of the ciliary marginal zone (CMZ). However, their cell-of-origin as well as the mechanisms that sustain their maintenance during development are presently unknown. We identified Hes4 (previously named XHairy2), a gene encoding a bHLH-O transcriptional(More)
The homeobox gene siamois is one of the earliest genes expressed in the Spemann organizer and plays a critical role in the formation of the dorsoventral axis. It is directly regulated by maternal Wnt signalling and functions as an essential zygotic intermediary between maternal factors and the formation of the Spemann organizer. The maternal T domain(More)
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