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At least 649 records · Page 36Linked to original sources
PubMed2000

Characterization of desmosomal component expression during palatogenesis.

Adhesion of the opposing palatal shelves is a critical first step in the mechanism for palatal fusion. Formation of desmosomal junctions between the two medial edge epithelia provides a mechanism for palatal shelf adhesion. RT-PCR and immunohistochemistry were used to determine the pattern of expression of desmosomal components during palatogenesis. Desmosomal expression was specifically upregulated in the medial edge epithelia (MEE) at the early stages of palatal fusion as detected by both immunohistochemistry and electron microscopy. RT-PCR characterization of the desmosomal components detected all known elements, except desmocollin 1 (DSC1). Desmocollin 2 (DSC2) was expressed as both the DSC2a and DSC2b variants. The two variants are expressed at the same level. Western analysis of desmoglein expression paralleled the RT-PCR result. The temporal and spatial upregulation of desmosomal gene expression is evidence that the MEE induce new gene expression required to accomplish palatal shelf adhesion and initiate the first stage of palatal fusion.

Animals↗
PubMed1997

Expression of DA11, a neuronal-injury-induced fatty acid binding protein, coincides with axon growth and neuronal differentiation during central nervous system development.

DA11 is the first fatty acid binding protein (FABP) for which gene expression has been shown to be upregulated following neuronal injury in the adult peripheral nervous system. To understand better the potential regulatory role(s) of this unique FABP in axonal growth and neuronal differentiation, we undertook a temporal and spatial study of DA11 gene expression in the developing rat central nervous system (CNS). Transient upregulation of DA11 mRNA and protein levels in CNS tissues were quantified by Northern blot hybridization and Western immunoblot analyses at different developmental ages. Homogenates of embryonic and neonatal cerebral cortex, cerebellum, brain stem, and hippocampal tissues contained 100-fold more DA11 mRNA and protein than corresponding adult tissues. Significant increase in DA11 mRNA was observed as early as embryonic day (E) 14 in cerebral cortex and cerebellum and E19 in brain stem and hippocampus. Postnatal levels of DA11 remained elevated through postnatal day (P) 10 in cerebral cortex, P14 in brain stem and hippocampus, and P20 in cerebellum. Localization of DA11-like immunoreactivity to specific CNS tissues, cell types, and intracellular compartments at P9 revealed a spatial pattern of neuronal expression different than that reported for other FABPs. DA11 protein was detected in the nucleus, cytoplasm, axons, and dendrites of differentiating neurons in cerebral cortex, hippocampus, cerebellum, brain stem, spinal cord, and olfactory bulb. The strong association of DA11 gene expression with development throughout the CNS suggests that this unique FABP plays an important role in axonal growth and neuronal differentiation in many different neuronal populations.

Animals↗
PubMed2003

Enrichment enhances the expression of sgk, a glucocorticoid-induced gene, and facilitates spatial learning through glutamate AMPA receptor mediation.

We have previously demonstrated that the serum and glucocorticoid-inducible kinase (sgk) gene plays a causal role in facilitating memory performance in rats. Environment enrichment is known to facilitate spatial learning. We therefore examined the effect of enrichment on sgk expression. We also examined the role of sgk in spatial and nonspatial learning and the regulation of sgk expression by activation of different glutamate receptors. Both real-time polymerase chain reaction and Western blot analyses revealed that enrichment training preferentially increased sgk mRNA and protein levels in the hippocampus. Transfection of sgk mutant DNA to the hippocampal CA1 area markedly impaired spatial learning, fear-conditioning learning and novel object-recognition learning in rats, but enrichment training effectively reversed these learning deficits. Meanwhile, S422A mutant DNA transfection prevented enrichment-induced spatial learning facilitation. In studying glutamate receptor regulation of sgk expression, we found that blockade of N-methyl-d-aspartate (NMDA) receptors in general, and the NR2B subunit in particular both effectively blocked enrichment-induced spatial learning facilitation, but they did not block enrichment-induced sgk expression. Upon various glutamate agonist infusions, only alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) increased sgk mRNA levels significantly in the hippocampus. Furthermore, blockade of AMPA receptors effectively blocked both enrichment-induced spatial learning facilitation and sgk expression. These results indicate that there is a dissociation between NMDA receptor activation and sgk expression. Enrichment enhanced spatial learning through both NMDA and AMPA receptor activation, whereas enrichment-induced sgk expression is specifically mediated through AMPA receptors. These results suggest that sgk could serve as a novel molecular mechanism, in addition to the NMDA receptor NR2B, underlying enrichment-induced learning facilitation.

Age Factors↗
PubMed2006

Differential regulation of gene expression in the digit forming area of the mouse limb bud by SHH and gremlin 1/FGF-mediated epithelial-mesenchymal signalling.

Spatially and temporally coordinated changes in gene expression are crucial to orderly progression of embryogenesis. We combine mouse genetics with experimental manipulation of signalling to analyze the kinetics by which the SHH morphogen and the BMP antagonist gremlin 1 (GREM1) control gene expression in the digit-forming mesenchyme of mouse limb buds. Although most mesenchymal cells respond rapidly to SHH signalling, the transcriptional upregulation of specific SHH target signals in the mesenchyme occurs with differential temporal kinetics and in a spatially restricted fashion. In particular, the expression of the BMP antagonist Grem1 is always upregulated in mesenchymal cells located distal to the SHH source and acts upstream of FGF signalling by the apical ectodermal ridge. GREM1/FGF-mediated feedback signalling is, in turn, required to propagate SHH and establish the presumptive digit expression domains of the Notch ligand jagged 1 (Jag1) and 5'Hoxd genes in the distal limb bud mesenchyme. Their establishment is significantly delayed in Grem1-deficient limb buds and cannot be rescued by specific restoration of SHH signalling in mutant limb buds. This shows that GREM1/FGF feedback signalling is required for regulation of the temporal kinetics of the mesenchymal response to SHH signalling. Finally, inhibition of SHH signal transduction at distinct time points reveals the differential temporal dependence of Grem1, Jag1 and 5'Hoxd gene expression on SHH signalling. In particular, the expression of Hoxd13 depends on SHH signal transduction significantly longer than does Hoxd11 expression, revealing that the reverse co-linear establishment, but not maintenance of their presumptive digit expression domains, depends on SHH signalling.

Animals↗
PubMed2005

Synthetic biology: engineering Escherichia coli to see light.

We have designed a bacterial system that is switched between different states by red light. The system consists of a synthetic sensor kinase that allows a lawn of bacteria to function as a biological film, such that the projection of a pattern of light on to the bacteria produces a high-definition (about 100 megapixels per square inch), two-dimensional chemical image. This spatial control of bacterial gene expression could be used to 'print' complex biological materials, for example, and to investigate signalling pathways through precise spatial and temporal control of their phosphorylation steps.

Agar↗
PubMed1991

Tissue-specific and developmental regulation of rod opsin chimeric genes in transgenic mice.

Chimeric gene fusions between 4.4 kb of rod opsin 5' flanking sequence fused to a diphtheria toxin gene and 4.4 kb or 500 bp of rod opsin 5' flanking sequence fused to the E. coli IacZ gene were used to generate transgenic mice for analysis of cell type-specific expression and temporal and spatial distribution of reporter gene product during retinal development. Opsin-diphtheria toxin transgene expression evoked photoreceptor-specific cell death. The 4.4 kb opsin-IacZ transgene followed temporal and spatial gradients of expression that approximate opsin expression. The 500 bp opsin fragment targeted expression to photoreceptors, but expression was weaker and nonuniform, suggesting that elements located upstream may be required for enhanced and uniform spatial expression.

Animals↗
PubMed1999

Small subfamily of olfactory receptor genes: structural features, expression pattern and genomic organization.

Olfactory receptors of the OR37 subfamily are characterized by distinct sequence features and are expressed in neurons segregated in a restricted area of the olfactory epithelium. In the present study, we have characterized the complement of OR37-like genes in the mouse. Five OR37-like genes were identified. They reside within only 60kb of DNA on chromosome 4. About 70kb distant from this cluster, two additional olfactory receptor genes are located, which are members of distinct receptor subfamilies. Phylogenetic analysis demonstrated that the two physically linked receptors are closely related to the OR37 subfamily. Studies of gene expression showed that both genes are also expressed in clustered neuron populations located in the typical OR37 region of the epithelium. These data suggest the involvement of locus-dependent mechanisms for the spatial control of OR gene expression.

Amino Acids↗
PubMed2004

Molecular imaging of the embryonic heart: Fables and facts on 3D imaging of gene expression patterns.

Molecular imaging, which is the three-dimensional (3D) visualization of gene expression patterns, is indispensable for the study of the function of genes in cardiac development. The instrumentation, as well as the development of specific contrast agents for molecular imaging, has shown spectacular advances in the last decade. In this review, the spatial resolutions, contrast agents, and applications of these imaging methods in the field of cardiac embryology are discussed. Apart from 3D reconstructions from histological sections, not many of these methods have been applied in embryological research. This review shows that, for most methods, neither the spatial resolutions nor the specificity and applicability of the contrast agents are adequate for the reliable imaging of specific gene expression at the microscopic resolution required for embryological studies of small organs like the developing heart. Although a 3D reconstruction from sections will always suffer from imperfections, the resulting reconstructions meet the aim of most biological studies, especially since the original microscopic images are linked. With respect to imaging of gene expression, only histological sections and laser scanning microscopy provide the required resolution and specificity at the tissue and cellular level. Episcopic fluorescence image capturing and optical projection tomography are being used for microscopic phenotyping and lineage analysis, and both show potential for detailed molecular imaging. Other methods can be used very efficiently in rapid evaluation of biological experiments and high-throughput screens of large-scale gene expression profiling efforts when high spatial resolution is not required.

Animals↗
PubMed2004

Using reporter genes to study cis-regulatory elements.

This chapter summarizes four powerful assays for analyzing gene expression in cis-regulatory studies. The enzymatic assays (CAT, luciferase, lacZ) are currently limited by their application to embryo homogenates or fixed samples, but offer more robust analysis of gene activity than GFP. Assays based on CAT enzymatic activity or on CAT mRNA detection by WMISH are laborious but are well established for accurately quantifying gene expression and to determine spatial patterns at defined timepoints during development. LacZ assays are the current standard for spatially visualizing gene products in whole-mount fixed embryos. They are very sensitive but they provide limited temporal or quantitative information due to the perdurance of beta-galactosidase and the subtleties of the staining technique. Recently developed luciferase assays promise to be even more sensitive and accurate than the CAT and lacZ assays, and applicable to living cells and embryos. But, they have not yet been well established in invertebrate deuterostome research. GFP allows visualization of gene expression within living embryos. But because this is not an enzymatic assay, sensitivity can be a problem, particularly for weak promoters. Furthermore, imaging live embryos and quantifying gene expression in space and time (due to scattering of light by tissue, the perdurance of GFP, and other experimental details) is currently fraught with challenges. Ongoing improvements in imaging technology and the advent of multiple fluorescent proteins, as well as fluorescent and luminescent assays for vital imaging, will dramatically facilitate studies of gene expression in the coming decade.

Animals↗
PubMed2006

Pharmacogenomics of phenolic antioxidant butylated hydroxyanisole (BHA) in the small intestine and liver of Nrf2 knockout and C57BL/6J mice.

PURPOSE: The objective of this study was to investigate the pharmacogenomics and the spatial regulation of global gene expression profiles elicited by cancer chemopreventive agent butylated hydroxyanisole (BHA) in mouse small intestine and liver as well as to identify BHA-modulated nuclear factor-E2-related factor 2 (Nrf2)-dependent genes. METHODS: C57BL/6J (+/+; wildtype) and C57BL/6J/Nrf2(-/-; knockout) mice were administered a single 200 mg/kg oral dose of BHA or only vehicle. Both small intestine and liver were collected at 3 h after treatment and total RNA was extracted. Gene expression profiles were analyzed using 45,000 Affymetrix mouse genome 430 2.0 array and GeneSpring 7.2 software. Microarray results were validated by quantitative real-time reverse transcription-PCR analyses. RESULTS: Clusters of genes that were either induced or suppressed more than two fold by BHA treatment compared with vehicle in C57BL/6J/Nrf2(-/-; knockout) and C57BL/6J Nrf2 (+/+; wildtype) mice genotypes were identified. Amongst these, in small intestine and liver, 1,490 and 493 genes respectively were identified as Nrf2-dependent and upregulated, and 1,090 and 824 genes respectively as Nrf2-dependent and downregulated. Based on their biological functions, these genes can be categorized into ubiquitination/proteolysis, apoptosis/cell cycle, electron transport, detoxification, cell growth/differentiation, transcription factors/interacting partners, kinases and phosphatases, transport, biosynthesis/metabolism, RNA/protein processing and nuclear assembly, and DNA replication genes. Phase II detoxification/antioxidant genes as well as novel molecular target genes, including putative interacting partners of Nrf2 such as nuclear corepressors and coactivators, were also identified as Nrf2-dependent genes. CONCLUSIONS: The identification of BHA-regulated and Nrf2-dependent genes not only provides potential novel insights into the gestalt biological effects of BHA on the pharmacogenomics and spatial regulation of global gene expression profiles in cancer chemoprevention, but also points to the pivotal role of Nrf2 in these biological processes.

Animals↗
PubMed2006

Toxicogenomics of endoplasmic reticulum stress inducer tunicamycin in the small intestine and liver of Nrf2 knockout and C57BL/6J mice.

This objective of this study was to investigate the toxicogenomics and the spatial regulation of global gene expression profiles elicited by endoplasmic reticulum (ER) stress inducer tunicamycin (TM) in mouse small intestine and liver as well as to identify TM-modulated nuclear factor-E2-related factor 2 (Nrf2)-dependent genes. Gene expression profiles were analyzed using 45,000 Affymetrix mouse genome 430 2.0 array and GeneSpring 7.2 software. Microarray results were validated by quantitative real-time reverse transcription-PCR analyses. Clusters of genes that were either induced or suppressed more than two-fold by TM treatment compared with vehicle in C57BL/6J/Nrf2 (-/-; knockout) and C57BL/6J Nrf2 (+/+; wildtype) mice genotypes were identified. Amongst these, in small intestine and liver, 1291 and 750 genes, respectively, were identified as Nrf2-dependent and upregulated, and 1370 and 943 genes, respectively, as Nrf2-dependent and downregulated. Based on their biological functions, these genes can be categorized into molecular chaperones and heat shock proteins, ubiquitination/proteolysis, apoptosis/cell cycle, electron transport, detoxification, cell growth/differentiation, signaling molecules/interacting partners, kinases and phosphatases, transport, biosynthesis/metabolism, nuclear assembly and processing, and genes related to calcium and glucose homeostasis. Phase II detoxification/antioxidant genes as well as putative interacting partners of Nrf2 such as nuclear corepressors and coactivators, were also identified as Nrf2-dependent genes. The identification of TM-regulated and Nrf2-dependent genes in the unfolded protein response to ER stress not only provides potential novel insights into the gestalt biological effects of TM on the toxicogenomics and spatial regulation of global gene expression profiles in cancer pharmacology and toxicology, but also points to the pivotal role of Nrf2 in these biological processes.

Animals↗
PubMed1999

Expression of doublecortin correlates with neuronal migration and pattern formation in diverse regions of the developing chick brain.

The development of functional layers in the brain involves spatially and temporally regulated gene expression. Through cDNA library screening, we have identified genes that are expressed in a neural-specific manner during brain development. Sequencing and expression data indicate that one of the clones, 18C15, is the chick homologue of doublecortin, a human X-linked gene found to be mutated in subcortical laminar heterotopia (double cortex syndrome) and lissencephaly. The 18C15 mRNA contains multiple motifs that are known to regulate mRNA stability in response to inductive signals, and these motifs are conserved between the chick and human sequences. Doublecortin is found to be expressed at peak levels during early development of the cerebellum and forebrain, and is expressed in other regions including the tectum, spinal cord, and dorsal root ganglia. This study demonstrates both spatial and temporal regulation of doublecortin expression in the chick, which is associated with early events in brain development, including neuronal migration.

3' Untranslated Regions↗
PubMed1991

The expression of murine Hox-2 genes is dependent on the differentiation pathway and displays a collinear sensitivity to retinoic acid in F9 cells and Xenopus embryos.

In this paper we describe experiments that detail the response of murine Hox-2 genes to cellular differentiation and retinoic acid in cell culture. Hox-2 genes are transiently activated in differentiating ES cells even in the absence of retinoic acid (RA), indicating that their induction is a normal aspect of differentiation. Furthermore, in the continuous presence of RA F9 teratocarcinoma cells show a differential ability to maintain Hox-2 expression depending upon whether the cells follow a visceral or parietal endoderm pathway. These data suggest a clear dependence of Hox-2 expression on the degree and type of differentiation in different cells. However, RA also has dramatic differentiation independent effects on Hox-2 regulation. In ES cells the levels of Hox expression are greatly enhanced by exposure to RA, and in F9 cells of the visceral or parietal phenotype the continuous presence of RA is required to maintain these high levels. Nuclear run-on experiments illustrate that Hox-2 genes are active in F9 stem cells and that a large portion of the RA induction is mediated by post-transcriptional mechanisms. Therefore RA exerts its effects on Hox-2 expression by upregulating or modulating genes which are already active, rather than by turning-on silent genes. All nine Hox-2 genes are induced in F9 cells by RA and there is a direct correlation (collinearity) between gene order and the relative dose response of each gene to RA. In Xenopus embryos treated with RA, homologues of the Hox-2 genes also displayed a temporal and dose response collinearity with gene organisation. Together these findings suggest that the collinear response to RA is highly conserved in vertebrates and combined with the ability of RA to modify expression during cellular differentiation could be an important feature of the Hox-2 cluster itself used to generate the spatially-restricted patterns of gene expression in embryogenesis.

Animals↗
PubMed1994

In situ hybridization analysis of anterior pituitary hormone gene expression during fetal mouse development.

We used 35S-labeled oligonucleotides and cRNAs (riboprobes) to detect the temporal order and spatial pattern of anterior pituitary hormone gene expression in (B6CBF1 x B6CBF1)F2 fetal mice from embryonic Day 9.5 (E9.5) to postnatal Day 1 (P1). Pro-opiomelanocortin (POMC) mRNA was expressed in the basal diencephalon on Day E10.5, in the ventromedial zone of the pars distalis on Day E12.5, and in the pars intermedia on Day E14.5. The common alpha-glycoprotein subunit (alpha-GSU) mRNA first appeared in the anterior wall of Rathke's pouch on Day E11.5 and extended to the pars tuberalis and ventromedial zone of the pars distalis on Day E12.5. Thyroid-stimulating hormone-beta (TSH beta) subunit mRNA was expressed initially in both the pas tuberalis and ventromedial pars distalis on Day E14.5, with an identical spatial distribution to alpha-GSU at the time. In contrast, luteinizing hormone-beta (LH beta) subunit and follicle-stimulating hormone beta (FSH beta) subunit mRNAs were detected initially only in the ventromedial pars distalis on Days E16.5 and E17.5, respectively, in an identical distribution to each other. POMC-, alpha-GSU-, TSH beta, LH beta-, and FSH beta-positive cells within the pars distalis all increased in number and autoradiographic signal with differing degrees of spatial expansion posteriorly, laterally, and dorsally up to Day P1. POMC expression was typically the most intense and extended circumferentially to include the entire lateral and dorsal surfaces of the pars distalis. The expression of both growth hormone (GH) and prolactin (PRL) started coincidentally on Day E15.5. However PRL cells localized in the ventromedial area similarly to POMC and the glycoprotein hormone subunits, whereas GH cells were found initially in a more lateral and central distribution within the lobes of the pars distalis. Somatotrophs increased dramatically in number and autoradiographic signal, extending throughout the pars distalis except for the most peripheral layer of cells on Day E17.5. Mammotrophs also increased in number but less abundantly than somatotrophs, and PRL expression remained more confined to central-medial and ventrolateral areas of the pars distalis up to Day P1. These data demonstrate distinctive patterns of expression for each of the major anterior pituitary hormone genes during development of the mouse pituitary gland and suggest that different groups of committed cells are the immediate precursors to the terminally differentiated hormone-secreting cell types.

Animals↗
PubMed1998

Interactions between Bmp-4 and Msx-1 act to restrict gene expression to odontogenic mesenchyme.

Tooth development is regulated by a reciprocal series of epithelial-mesenchymal interactions. Bmp4 has been identified as a candidate signalling molecule in these interactions, initially as an epithelial signal and then later at the bud stage as a mesenchymal signal (Vainio et al. [1993] Cell 75:45-58). A target gene for Bmp4 signalling is the homeobox gene Msx-1, identified by the ability of recombinant Bmp4 protein to induce expression in mesenchyme. There is, however, no evidence that Bmp4 is the endogenous inducer of Msx-1 expression. Msx-1 and Bmp-4 show dynamic, interactive patterns of expression in oral epithelium and ectomesenchyme during the early stages of tooth development. In this study, we compare the temporal and spatial expression of these two genes to determine whether the changing expression patterns of these genes are consistent with interactions between the two molecules. We show that changes in Bmp-4 expression precede changes in Msx-1 expression. At embryonic day (E)10.5-E11.0, expression patterns are consistent with BMP4 from the epithelium, inducing or maintaining Msx-1 in underlying mesenchyme. At E11.5, Bmp-4 expression shifts from epithelium to mesenchyme and is rapidly followed by localised up-regulation of Msx-1 expression at the sites of Bmp-4 expression. Using cultured explants of developing mandibles, we confirm that exogenous BMP4 is capable of replacing the endogenous source in epithelium and inducing Msx-1 gene expression in mesenchyme. By using noggin, a BMP inhibitor, we show that endogenous Msx-1 expression can be inhibited at E10.5 and E11.5, providing the first evidence that endogenous Bmp-4 from the epithelium is responsible for regulating the early spatial expression of Msx-1. We also show that the mesenchymal shift in Bmp-4 is responsible for up-regulating Msx-1 specifically at the sites of future tooth formation. Thus, we establish that a reciprocal series of interactions act to restrict expression of both genes to future sites of tooth formation, creating a positive feedback loop that maintains expression of both genes in tooth mesenchymal cells.

Animals↗
PubMed2000

Gene transfer into individual muscle fibers and conditional gene expression in living animals.

Pressure injection of DNA directly into individual fibers of surgically exposed soleus muscle leads to efficient and reliable expression of the transgene. Conditionally regulated gene expression in a single muscle fiber was analyzed in vivo by co-injecting a tetracycline-regulated lacZ reporter construct and a transactivator (rtTA) expression vector. The tetracycline-responsive element revealed significant basal transcriptional activity that was further increased by rtTA even in the absence of the effector doxycycline (dox). The high basal activity of the simple two-component system precludes tight gene regulation in muscle. Concomitant expression of the silencer tTS(Kid), however, reduced the basal activity to low or undetectable levels. This allowed the specific activation of the tetracycline-responsive element by the application of dox. Direct gene transfer can thus be employed to express transgenic proteins in distinct muscle fibers at spatially defined regions and to regulate gene expression conditionally.

Animals↗
PubMed1995

Wnt expression patterns in chick embryo nervous system.

Several lines of evidence suggest that Wnt genes play a critical role in regulating development of the vertebrate embryo. To address the role that this family may play in the development of the chicken central nervous system (CNS), we have used a PCR based strategy to clone partial sequences for Wnt genes. At least six different Wnt genes are expressed in the developing CNS of the chick embryo. The domains of expression overlap either partially or completely, and are expressed in spatial domains that prefigure morphological subunits of the embryonic neural tube. Wnt-1 and Wnt-4 are first expressed in the open neural plate in the region of the presumptive mesencephalon. Wnt-3a expression is first observed in the rhombencephalic regions of the open neural plate. After neural tube closure, when the embryonic subdivisions of the neural tube became apparent, Wnt-1, Wnt-3a and Wnt-4 are all broadly expressed in partially overlapping domains in the mesencephalon and caudal diencephalon, as well as in the rhombencephalon and spinal cord. The mesencephalic expression patterns are subsequently modified such that Wnt-1 and Wnt-4 are expressed in a characteristic ring just rostral to the isthmus, at the mesencephalic/metencephalic junction; and Wnt-1 and Wnt-3a expression become restricted to the dorsal midline. Wnt-1, Wnt-3a, Wnt-4, Wnt-5a and Wnt-8b are expressed in one or two caudal subdivisions of the developing diencephalon, the synencephalon and posterior parencephalon, but do not extend ventral to the zona limitans interparencephalica. In contrast, Wnt-7b is expressed in the anterior parencephalon. Both Wnt-7b and Wnt-8b are expressed in telencephalic portions of the secondary prosencephalon. The timing and spatial distribution of Wnt-gene expression in the chick embryo further support the general hypothesis that Wnt genes play key roles in patterning the developing vertebrate nervous system.

Amino Acid Sequence↗
PubMed1995

Differential display analysis of gene expression in developing embryos of Xenopus laevis.

Differential display (DD), an arbitrarily primed RT-PCR fingerprinting technique, is a novel approach for the search of differentially expressed transcripts. Using our improved DD protocol, reproducible cDNA fingerprints were successfully obtained from RNAs of Xenopus laevis embryos at six representative stages. Parallel comparison among the fingerprints revealed a number of bands with differential expression patterns. Analysis with clones of three randomly chosen bands confirmed that their expression patterns were faithfully reflected on fingerprints, thereby proving the reliability and validity of the approach. Nucleotide sequencing of these clones revealed that one is identical with a known transcript (cardiac actin), the second is a novel developmentally regulated gene showing no significant homology with those reported previously, and the last is a close but unique relative of XK endo B gene showing somewhat different spatial expression pattern. These results indicated that the DD analysis provides a rapid and reliable way for the identification of novel differentially expressed genes as well as a unique 'scope' for the survey of the changes in overall gene expression profiles occurring in the early embryonic development of Xenopus as well as of other organisms.

Amino Acid Sequence↗