Showing papers in "Developmental Biology in 1999"

TL;DR: In this article, the authors investigated the mechanism of lin-4 RNA action by examining the fate of Lin-14 mRNA in vivo during the time that lin4 RNA is expressed, and they found that association of lin 4 RNA with the 3* untranslated region (UTR) of Lin 14 mRNA permits normal biogenesis of lin 14 mRNA, and normal translational initiation, but inhibits step(s) thereafter, such as translational elongation and/or release of stable LIN-14 protein.

TL;DR: The results support a model in which separate, lineage-related EGF- and FGF-responsive neural stem cells are present in the embryonic telencephalic germinal zone, and show that EGF alone and F GF2 alone can independently elicit neural stem cell proliferation and at relatively high cell densities separate cell nonautonomous effects can substantially enhance the mitogen-induced proliferation.

TL;DR: It is indicated that cell cycling related to leaf morphogenesis, tissue-specific patterns of cell proliferation, and cell differentiation occurs concurrently during leaf development and suggest that unique regulatory pathways may operate at each level.

TL;DR: Findings fail to support the dichotomy in calcium signaling modes that had previously been proposed for protostomes vs deuterostomes and instead suggest that various features of fertilization-induced calcium signals are widely shared throughout the animal kingdom.

TL;DR: Signalling molecules activated downstream of gp130 in ES cells include STAT3, the protein tyrosine phosphatase SHP-2, and the mitogen-activated protein kinases, ERK1 and ERK2, which imply that the self-renewal signal from gp130 is a finely tuned balance of positive and negative effectors.

TL;DR: This double-reporter transgenic line is able to indicate the occurrence of Cre excision in an extremely widespread manner from early embryonic to adult lineages and will be a valuable reagent for the increasing number of investigators taking advantage of the powerful tools provided by the Cre/loxP site-specific recombinase system.

TL;DR: Roles for chemokine signaling in multiple embryogenic events are suggested, particularly at earlier times (E7.5 and E8.5), with an optimum dose similar to that found for adult hematopoietic cells and was dependent on the presence of SDF-1 in a gradient.

TL;DR: An obligatory role for the secreted morphogen Sonic hedgehog (Shh) during hair follicle development is reported, where it is required for normal advancement beyond the hair germ stage of development.

TL;DR: The role of T-box transcription factor, Tbx5, in cardiac development has been examined in the developing mouse and chick heart and correlated this pattern with cardiac defects caused by human TBX5 mutations in Holt-Oram syndrome.

TL;DR: Examination of expression patterns of two zebrafish cardiac myosin genes allow us to distinguish two populations of myocardial precursors at an early stage, well before the heart tube forms and suggest new models for the mechanisms that regulate the formation of a patterned heart tube.

TL;DR: By systematically altering the germ cell contents of the hermaphrodite using mutant strains, this work has uncovered evidence of four cell-cell interactions that regulate maturation and ovulation in Caenorhabditis elegans.

TL;DR: Based on sequence, map position, and expression patterns, it is suggested that Dmrt1 is likely to play a role in vertebrate sexual development and therefore that DM domain genes may play a roles in sexual development in a wide range of phyla.

TL;DR: A critical role is demonstrated for Nkx2.1 in morphogenesis of the anterior foregut and the lung as well as in differentiation of pulmonary epithelial cells.

TL;DR: In tissue culture cells, VEGF mRNA expression was induced by glucose deprivation independent of HIF-1alpha, providing a mechanism for increased VEGf mRNA expression in Hif1a-/- embryos, in which absence of adequate tissue perfusion resulted in both O2 and glucose deprivation.

TL;DR: A review of the role of proteins in the female oocyte death pathway can be found in this paper, with a focus on those studies using genetic-null or transgenic models to explore the functional requirement of proteins.

TL;DR: Results indicate that GDF5 is necessary and sufficient for both cartilage development and the restriction of joint formation to the appropriate location, and demonstrates a link between cartilageDevelopment and joint development and is an important determinant of the pattern of bones and articulations in the digits.

TL;DR: It is concluded that juvenile hormone is a downstream component in the Sex-Peptide response cascade and acts by stimulating vitellogenic oocyte progression and inhibiting apoptosis and the balance of these hormones in the hemolymph regulates whether oocytes will progress through the control point at stage 9 or undergo apoptosis.

TL;DR: The formation of this central patch, previously considered as the start of retinal neurogenesis, was actually a secondary event, with a developmental history of its own, which indicates that cell birthday and cell fate were correlated within a column.

TL;DR: Genetic studies in Drosophila are now expanding to include multiple BMP ligands and receptors and have uncovered activities not explained by the current signal transduction model, suggesting that all TGF-beta signalTransduction pathways are present in flies.

TL;DR: Prolactin affects mammary morphogenesis in two different ways: it controls ductal side branching and terminal end bud regression in virgin animals via indirect mechanisms, but acts directly on the mammary epithelium to produce lobuloalveolar development during pregnancy.

TL;DR: Results show that an intact base excision repair pathway is essential for normal early postimplantation mouse development and implicate an endogenous source of DNA damage in the lethal phenotype of embryos lacking this repair capacity.

TL;DR: It is demonstrated that cholesterol release is associated with the activation of a transmembrane signal transduction pathway involving PK-A and protein tyrosine phosphorylation, leading to functional maturation of the sperm.

TL;DR: The data allow the correlation of the differential expression of pro and/or active forms of M MP-2 and MMP-9 with different stages of the degeneration-regeneration process: MMP -9 expression is related to the inflammatory response and probably to the activation of satellite cells, whereas Mmp-2 activation is concomitant with the regeneration of new myofibers.

TL;DR: It is demonstrated that the mouse SLIT1 protein can bind ROBO1, a transmembrane receptor implicated in axon guidance, and the unique expression pattern in limb and other organs indicates additional potential functions of the Slit gene family.

TL;DR: In this paper, the authors describe ultrastructural features relating to essential germline events and the soma-germline interactions upon which they depend, as revealed by electron and fluorescence microscopy.

TL;DR: A previously unrecognized role for WNT signaling in the control of hair growth and structure is demonstrated, as well as presenting the first example of a mammalian phenotype resulting from overexpression of a Dvl gene and providing an accessible in vivo system for analysis of mammalian Wnt signaling pathways.

TL;DR: A structural and functional conservation of the Pax6 regulatory elements in the vertebrate genome is indicated and Corresponding regulatory elements from pufferfish are able to mimic the reporter expression in transgenic mice.

TL;DR: Cer1, Drm, PRDC, Dan, and Dteis were found to play important roles in patterning the developing embryo in the mouse as mentioned in this paper, showing that the region of homology shared by these genes, here called the can domain, closely resembles the cysteine knot motif found in a number of signaling molecules such as members of the TGFβ superfamily.

TL;DR: Although different populations of mesodermal precursors are generated normally in casanova mutants, morphogenetic defects in the heart, vasculature, blood, and kidney are apparent, suggesting a possible role for the endoderm in morphogenesis of these organs.

TL;DR: It is believed that the LacZ-tagged allele generated offers a precise means of detecting VEGF expression under a variety of physiological and pathological conditions.