Publications by authors named "Chantal Wicky"

The intersection of metabolic processes and epigenetic regulation during embryogenesis is crucial yet not fully understood. Through a candidate RNAi screen in , we identified metabolic enzymes ALDO-2 and PDHB-1 as potential epigenetic regulators. Mild alteration of the chromatin remodeler LET-418 /Mi2 activity rescues embryonic lethality induced by suppressing or suggesting a critical role for glucose and pyruvate metabolism in chromatin remodeling during embryogenesis.

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Today, agriculture around the world is challenged by parasitic nematode infections. Plant-parasitic nematodes (PPNs) can cause significant damage and crop loss and are a threat to food security. For a long time, the management of PPN infection has relied on nematicides that impact not only parasitic nematodes but also other organisms.

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Background: The glucocorticoid receptor (GR), which is encoded by the NR3C1 (Nuclear Receptor Subfamily 3 Group C Member 1) gene plays an important role in the modulation of the hypothalamic-pituitary-adrenal (HPA) axis activity by providing feedback regulation which allows termination of the stress response. Little is known about epigenetic programming at the level of NGFI-A (nerve growth factor-inducible protein A) putative binding site (CpG) of the NR3C1 exon 1F in dyads mother-child exposed to intimate partner violence (IPV) more specifically in an unstudied region such as the sub-Saharan Africa where levels of violence are very high.

Objective: Examine NR3C1 exon 1F methylation in response to IPV and possible association with cortisol concentration and mental health.

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Specific gene transcriptional programs are required to ensure the proper proliferation and differentiation processes underlying the production of specialized cells during development. Gene activity is mainly regulated by the concerted action of transcription factors and chromatin proteins. In the nematode Caenorhabditis elegans, mechanisms that silence improper transcriptional programs in germline and somatic cells have been well studied, however, how are tissue-specific sets of genes turned on is less known.

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Background: The experience of intimate partner violence (IPV) is stressful. One objective way to monitor it is to assess victims' stress response by measuring the concentration of their salivary cortisol, the major stress hormone released by the hypothalamic-pituitary-adrenal axis.

Objective: We investigated how the IPV experienced by women in Cameroon affects their stress levels and those of their children.

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Intimate partner violence (IPV) is a widespread social problem with serious consequences for the health of both women and their children. However, little is known about the combined effect of maternal childhood abuse and current exposure to IPV with respect to the psychopathological symptoms of the mother-child dyad. In a Cameroonian cultural setting, where IPV affects more than half of women, we aimed to better understand how mother's childhood abuse and current IPV co-occur to lead to psychopathological symptoms in the mother-child dyad.

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Chromatin condition is crucial for the cells to respond to their environment. In , post-embryonic development is accompanied by the exit of progenitor cells from quiescence in response to food. The chromatin protein LET-418/Mi2 is required for this transition in development indicating that proper chromatin structure in cells of the freshly hatched larvae is important to respond to food.

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The Green Fluorescent Protein (GFP) has been tremendously useful in investigating cell architecture, protein localization, and protein function. Recent developments in transgenesis and genome editing methods now enable working with fewer transgene copies and, consequently, with physiological expression levels. However, lower signal intensity might become a limiting factor.

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Mi2 proteins are evolutionarily conserved, ATP-dependent chromatin remodelers of the CHD family that play key roles in stem cell differentiation and reprogramming. In , the gene encodes one of the two Mi2 homologs, which is part of at least two chromatin complexes, namely the Nucleosome Remodeling and histone Deacetylase (NuRD) complex and the MEC complex, and functions in larval development, vulval morphogenesis, lifespan regulation, and cell fate determination. To explore the mechanisms involved in the action of LET-418/Mi2, we performed a genome-wide RNA interference (RNAi) screen for suppressors of early larval arrest associated with mutations.

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Background: The nucleosome remodeling and deacetylase complex promotes cell fate decisions throughout embryonic development. Its core enzymatic subunit, the SNF2-like ATPase and Helicase Mi2, is well conserved throughout the eukaryotic kingdom and can be found in multiple and highly homologous copies in all vertebrates and some invertebrates. However, the reasons for such duplications and their implications for embryonic development are unknown.

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Background: Epimorphic regeneration of a missing appendage in fish and urodele amphibians involves the creation of a blastema, a heterogeneous pool of progenitor cells underneath the wound epidermis. Current evidence indicates that the blastema arises by dedifferentiation of stump tissues in the vicinity of the amputation. In response to tissue loss, silenced developmental programs are reactivated to form a near-perfect copy of the missing body part.

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Throughout their journey to forming new individuals, germline stem cells must remain totipotent, particularly by maintaining a specific chromatin structure. However, the place epigenetic factors occupy in this process remains elusive. So far, "sensitization" of chromatin by modulation of histone arrangement and/or content was believed to facilitate transcription-factor-induced germ cell reprogramming.

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The evolutionarily conserved nucleosome-remodeling protein Mi2 is involved in transcriptional repression during development in various model systems, plays a role in embryonic patterning and germ line development, and participates in DNA repair and cell cycle progression. It is the catalytic subunit of the nucleosome remodeling and histone deacetylase (NuRD) complex, a key determinant of differentiation in mammalian embryonic stem cells. In addition, the Drosophila and C.

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Biochemical purifications from mammalian cells and Xenopus oocytes revealed that vertebrate Mi-2 proteins reside in multisubunit NuRD (Nucleosome Remodeling and Deacetylase) complexes. Since all NuRD subunits are highly conserved in the genomes of C. elegans and Drosophila, it was suggested that NuRD complexes also exist in invertebrates.

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Programmed cell death (PCD) is an essential and highly orchestrated process that plays a major role in morphogenesis and tissue homeostasis during development. In humans, defects in regulation or execution of cell death lead to diabetes, neurodegenerative disorders, and cancer. Two major types of PCD have been distinguished: the caspase-mediated process of apoptosis and the caspase-independent process involving autophagy.

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Bloom's syndrome (BS) is an autosomal-recessive human disorder caused by mutations in the BS RecQ helicase and is associated with loss of genomic integrity and an increased incidence of cancer. We analyzed the mitotic and the meiotic roles of Caenorhabditis elegans him-6, which we show to encode the ortholog of the human BS gene. Mutations in him-6 result in an enhanced irradiation sensitivity, a partially defective S-phase checkpoint, and in reduced levels of DNA-damage induced apoptosis.

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