Search results for "Morphogen"
showing 10 items of 258 documents
Independence between developmental stability and canalization in the skull of the house mouse.
2000
The relationship between the two components of developmental homeostasis, that is canalization and developmental stability (DS), is currently debated. To appraise this relationship, the levels and morphological patterns of interindividual variation and fluctuating asymmetry were assessed using a geometric morphometric approach applied to the skulls of laboratory samples of the house mouse. These three samples correspond to two random-bred strains of the two European subspecies of the house mouse and their F1 hybrids. The inter- and intraindividual variation levels were found to be smaller in the hybrid group compared to the parental ones, suggesting a common heterotic effect on skull canali…
Histones, Their Variants and Post-translational Modifications in Zebrafish Development.
2020
Complex multi-cellular organisms are shaped starting from a single-celled zygote, owing to elaborate developmental programs. These programs involve several layers of regulation to orchestrate the establishment of progressively diverging cell type-specific gene expression patterns. In this scenario, epigenetic modifications of chromatin are central in influencing spatiotemporal patterns of gene transcription. In fact, it is generally recognized that epigenetic changes of chromatin states impact on the accessibility of genomic DNA to regulatory proteins. Several lines of evidence highlighted that zebrafish is an excellent vertebrate model for research purposes in the field of developmental ep…
The maternal hormone in the male brain: Sexually dimorphic distribution of prolactin signalling in the mouse brain.
2018
Research of the central actions of prolactin is highly focused on females, but this hormone has also documented roles in male physiology and behaviour. Here, we provide the first description of the pattern of prolactin-derived signalling in the male mouse brain, employing the immunostaining of phosphorylated signal transducer and activator of transcription 5 (pSTAT5) after exogenous prolactin administration. Next, we explore possible sexually dimorphic differences by comparing pSTAT5 immunoreactivity in prolactin-supplemented males and females. We also assess the role of testosterone in the regulation of central prolactin signalling in males by comparing intact with castrated prolactin-supp…
Segment polarity and DV patterning gene expression reveals segmental organization of theDrosophilabrain
2003
The insect brain is traditionally subdivided into the trito-, deuto- and protocerebrum. However, both the neuromeric status and the course of the borders between these regions are unclear. The Drosophila embryonic brain develops from the procephalic neurogenic region of the ectoderm, which gives rise to a bilaterally symmetrical array of about 100 neuronal precursor cells, called neuroblasts. Based on a detailed description of the spatiotemporal development of the entire population of embryonic brain neuroblasts, we carried out a comprehensive analysis of the expression of segment polarity genes (engrailed, wingless, hedgehog, gooseberry distal,mirror) and DV patterning genes (muscle segmen…
Crude oil exposures reveal roles for intracellular calcium cycling in haddock craniofacial and cardiac development.
2016
AbstractRecent studies have shown that crude oil exposure affects cardiac development in fish by disrupting excitation-contraction (EC) coupling. We previously found that eggs of Atlantic haddock (Melanogrammus aeglefinus) bind dispersed oil droplets, potentially leading to more profound toxic effects from uptake of polycyclic aromatic hydrocarbons (PAHs). Using lower concentrations of dispersed crude oil (0.7–7 μg/L ∑PAH), here we exposed a broader range of developmental stages over both short and prolonged durations. We quantified effects on cardiac function and morphogenesis, characterized novel craniofacial defects, and examined the expression of genes encoding potential targets underly…
Growth and differentiation factor 11 (GDF11): Functions in the regulation of erythropoiesis and cardiac regeneration
2015
International audience; Members of the TGF-β superfamily transduce their signals through type I and II receptor serine/threonine kinases. The binding of activins to activin type IIA (ActRIIA) or type IIB (ActRIIB) receptors induces the recruitment and phosphorylation of an activin type I receptor (ALK4 and/or ALK7), which then phosphorylates the Smad2 and Smad3 intracellular signaling proteins. The regulation of members of the TGF-β family is known to be complex, because many proteins able to bind the ligands and inhibit their activities have been identified. Growth and differentiation factor 11 (Gdf11) belongs to the TGF-β family. GDF11, like other members of the TGF-β superfamily, is prod…
Chemical skin carcinogenesis is prevented in mice by the induced expression of a TGF-β related transgene
1995
Skin papillomas and squamous cell carcinomas (SCCs) are induced in mice by tumor initiation with a carcinogen followed by tumor promotion with the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA). These usually arise from preneoplastic lesions characterized by epidermal proliferation and hyperplasia, dermal edema, and inflammation. To evaluate the role of polypeptide growth factors in chemically induced skin carcinogenesis, we used transgenic mice carrying the cDNA for a TGF-β related molecule, bone morphogenetic protein-4 (BMP-4), under the control of the regulatory elements of the cytokeratin IV* gene in a skin carcinogenesis protocol. Control non-transgenic littermates and BMP-4 …
Immobilization of BMP‐2, BMP‐7 and alendronic acid on titanium surfaces: Adhesion, proliferation and differentiation of bone marrow‐derived stem cells
2019
This study analyzed the influence of titanium (TiO2 ) surface modifications with two osteogenic proteins (BMP-2, BMP-7) and an anti-osteoclastic drug (alendronic acid [AA]) on sandblasted/acid-etched (SLA) and plain TiO2 (PT) on cell adhesion, proliferation and differentiation (alkaline phosphatase [AP] and osteocalcin [OC]) of bone-marrow derived stem cells (BMSCs) after 1, 3 and 7 days in-vitro. Initially, AA surfaces showed the highest cell number and surface coverage. At day 3 and 7, BMP and AA-modified surfaces exhibited a significantly enhanced cell growth. For proliferation, at days 3 and 7, an enhancement on BMP-2, BMP-7 and AA-surfaces was seen. At day 7, SLA also showed a higher p…
A luminal glycoprotein drives dose-dependent diameter expansion of the Drosophila melanogaster hindgut tube
2012
An important step in epithelial organ development is size maturation of the organ lumen to attain correct dimensions. Here we show that the regulated expression of Tenectin (Tnc) is critical to shape the Drosophila melanogaster hindgut tube. Tnc is a secreted protein that fills the embryonic hindgut lumen during tube diameter expansion. Inside the lumen, Tnc contributes to detectable O-Glycans and forms a dense striated matrix. Loss of tnc causes a narrow hindgut tube, while Tnc over-expression drives tube dilation in a dose-dependent manner. Cellular analyses show that luminal accumulation of Tnc causes an increase in inner and outer tube diameter, and cell flattening within the tube wall,…
Morphogenesis in Root Tip Meristem Cultures of Digitalis obscura L.
1987
Summary The morphogenic capacity of Digitalis obscura L. root tip meristems cultured in vitro has been studied, noting hormonal factors inducing differentiation and development of shoots as well as those promoting somatic embryogenesis. Caulogenesis was obtained with different auxin/cytokinin combinations but a high rate of shoot regeneration was induced by 0.1 or 0.5 ppm IAA and 1.0 ppm BA. Different stages of somatic embryo development were observed in media supplemented with auxins or high auxin/cytokinin ratios, although no complete plant regeneration was achieved. This is the first report known of shoot regeneration from root tips of Digitalis obscura L.