共查询到20条相似文献,搜索用时 31 毫秒
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Jessica L. Flesher Elyse K. Paterson‐Coleman Priya Vasudeva Rolando Ruiz‐Vega Michaela Marshall Eric Pearlman Grant R. MacGregor Jonathan Neumann Anand K. Ganesan 《Pigment cell & melanoma research》2020,33(2):279-292
MITF, a gene that is mutated in familial melanoma and Waardenburg syndrome, encodes multiple isoforms expressed from alternative promoters that share common coding exons but have unique amino termini. It is not completely understood how these isoforms influence pigmentation in different tissues and how the expression of these independent isoforms of MITF is regulated. Here, we show that melanocytes express two isoforms of MITF, MITF‐A and MITF‐M. The expression of MITF‐A is partially regulated by a newly identified retinoid enhancer element located upstream of the MITF‐A promoter. Mitf‐A knockout mice have only subtle changes in melanin accumulation in the hair and reduced Tyr expression in the eye. In contrast, Mitf‐M‐null mice have enlarged kidneys, lack neural crest‐derived melanocytes in the skin, choroid, and iris stroma, yet maintain pigmentation within the retinal pigment epithelium and iris pigment epithelium of the eye. Taken together, these studies identify a critical role for MITF‐M in melanocytes, a minor role for MITF‐A in regulating pigmentation in the hair and Tyr expression in the eye, and a novel role for MITF‐M in size control of the kidney. 相似文献
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Background
The regulation of proneural gene expression is an important aspect of neurogenesis. In the study of the Drosophila proneural genes, scute and atonal, several themes have emerged that contribute to our understanding of the mechanism of neurogenesis. First, spatial complexity in proneural expression results from regulation by arrays of enhancer elements. Secondly, regulation of proneural gene expression occurs in distinct temporal phases, which tend to be under the control of separate enhancers. Thirdly, the later phase of proneural expression often relies on positive autoregulation. The control of these phases and the transition between them appear to be central to the mechanism of neurogenesis. We present the first investigation of the regulation of the proneural gene, amos. 相似文献7.
Julian A. T. Dow 《Journal of bioenergetics and biomembranes》1999,31(1):75-84
In animals, V-ATPases are believed to play roles in the plasma membrane,as well as endomembrane. To understand these different functions, it isnecessary to adopt a genetic approach in a physiologically tractable modelorganism. For this purpose, Drosophila melanogaster is ideal,because of the powerful genetics associated with the organism and because ofthe unusually informative epithelial phenotype provided by the Malpighiantubule. Recently, the first animal knockouts of a V-ATPase weredescribed in Drosophila. The resulting phenotypes have generalutility for our understanding of V-ATPase function and suggest a screen fornovel subunits and associated proteins. Genome project resources haveaccelerated our knowledge of the V-ATPase gene family size and the newDrosophila genes vhaSFD, vha100-1, vha100-2, vha100-3, vha16-2,vha16-3, vha16-4, vhaPPA1, vhaPPA2, vhaM9.7.1, and vhaM9.7.2are described. The Drosophila V-ATPase model is thus well-suited toboth forward and reverse genetic analysis of this complex multifunctionalenzyme. 相似文献
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《European journal of cell biology》2022,101(4):151279
Bulk production and release of glue containing secretory granules takes place in the larval salivary gland during Drosophila development in order to attach the metamorphosing animal to a dry surface. These granules undergo a maturation process to prepare glue for exocytosis, which includes homotypic fusions to increase the size of granules, vesicle acidification and ion uptake. The steroid hormone 20-hydroxyecdysone is known to be required for the first and last steps of this process: glue synthesis and secretion, respectively. Here we show that the B1 isoform of Ecdysone receptor (EcR), together with its binding partner Ultraspiracle, are also necessary for the maturation of glue granules by promoting their acidification via regulation of Vha55 expression, which encodes an essential subunit of the V-ATPase proton pump. This is antagonized by the EcR-A isoform, overexpression of which decreases EcR-B1 and Vha55 expression and glue granule acidification. Our data shed light on a previously unknown, ecdysone receptor isoform-specific regulation of glue granule maturation. 相似文献
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The development of external sensory organs on the notum of Drosophila is promoted by the proneural genes achaete and scute. Their activity defines proneural cell clusters in the wing imaginal disc. Ectopic expression, under control of the GAL4 system, of the proneural gene lethal of scute (l'sc) causes the development of ectopic bristles. Persistent ectopic expression of l'sc is not sufficient to impose a neural fate on any given cell. This implies that mutual inhibition, mediated by the Notch signaling pathway, occurs among the cells of the ectopic proneural cluster. Consequently, the dominant, quantifiable phenotype
associated with ectopic expression of l'sc is modified by mutations in genes known to be involved in neurogenesis. This phenotype has been utilized to screen for dominant
enhancers and suppressors that modify the number of ectopic bristles. In this way, about 100 000 progeny of EMS or X-ray-treated
flies have been analyzed to identify autosomal genes involved in regulation of the neural fate. In addition 1200 chromosomes
carrying lethal P-element insertions were screened for modifiers. Besides mutations in genes expected to modify the phenotype,
we have isolated mutations in six genes not known so far to be involved in neurogenesis.
Received: 20 September 1997 / Accepted: 8 October 1997 相似文献
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Regulation of TFEB and V-ATPases by mTORC1 总被引:2,自引:0,他引:2
Peña-Llopis S Vega-Rubin-de-Celis S Schwartz JC Wolff NC Tran TA Zou L Xie XJ Corey DR Brugarolas J 《The EMBO journal》2011,30(16):3242-3258
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Lucas Sánchez F. Casares Nicole Gorfinkiel I. Guerrero 《Development genes and evolution》1997,207(4):216-228
The genital disc of Drosophila, which gives rise to the genitalia and analia of adult flies, is formed by cells from different embryonic segments. To study
the organization of this disc, the expressions of segment polarity and homeotic genes were investigated. The organization
of the embryonic genital primordium and the requirement of the engrailed and invected genes in the adult terminalia were also analysed. The results show that the three primordia, the female and male genitalia
plus the analia, are composed of an anterior and a posterior compartment. In some aspects, each of the three primordia resemble
other discs: the expression of genes such as wingless and decapentaplegic in each anterior compartment is similar to that seen in leg discs, and the absence of engrailed and invected cause duplications of anterior regions, as occurs in wing discs. The absence of lineage restrictions in some regions of the
terminalia and the expression of segment polarity genes in the embryonic genital disc suggest that this model of compartmental
organization evolves, at least in part, as the disc grows. The expression of homeotic genes suggests a parasegmental organization
of the genital disc, although these genes may also change their expression patterns during larval development.
Received: 4 February 1997 / Accepted: 22 May 1997 相似文献
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