scholarly journals Molecular characterization and expression of the stratification-related cytokeratins 4 and 15.

1988 ◽  
Vol 106 (4) ◽  
pp. 1249-1261 ◽  
Author(s):  
R E Leube ◽  
B L Bader ◽  
F X Bosch ◽  
R Zimbelmann ◽  
T Achtstaetter ◽  
...  
Keyword(s):  
Basal Cell ◽  
Blot Hybridization ◽  
Northern Blot Hybridization ◽  
Type I ◽  
Specific Expression ◽  
Genes Encoding ◽  
Cell Layers ◽  
Hybridization In Situ ◽  
Stratified Epithelia

A number of human cytokeratins are expressed during the development of stratified epithelia from one-layered polar epithelia and continue to be expressed in several adult epithelial tissues. For studies of the regulation of the synthesis of stratification-related cytokeratins in internal tissues, we have prepared cDNA and genomic clones encoding cytokeratin 4, as a representative of the basic (type II) cytokeratin subfamily and cytokeratin 15, as representative of the acidic (type I) subfamily, and determined their nucleotide sequences. The specific expression of mRNAs encoding these two polypeptides in certain stratified tissues and cultured cell lines is demonstrated by Northern blot hybridization. Hybridization in situ with antisense riboprobes and/or synthetic oligonucleotides shows the presence of cytokeratin 15 mRNA in all layers of esophagus, whereas cytokeratin 4 mRNA tends to be suprabasally enriched, although to degrees varying in different regions. We conclude that the expression of the genes encoding these stratification-related cytokeratins starts already in the basal cell layer and does not depend on vertical differentiation and detachment from the basal lamina. Our results also show that simple epithelial and stratification-related cytokeratins can be coexpressed in basal cell layers of certain stratified epithelia such as esophagus. Implications of these findings for epithelial differentiation and the formation of squamous cell carcinomas are discussed.

scholarly journals Expression of simple epithelial type cytokeratins in stratified epithelia as detected by immunolocalization and hybridization in situ.

1988 ◽  
Vol 106 (5) ◽  
pp. 1635-1648 ◽  
Author(s):  
F X Bosch ◽  
R E Leube ◽  
T Achtstätter ◽  
R Moll ◽  
W W Franke
Keyword(s):  
In Situ Hybridization ◽  
Basal Cell ◽  
Cell Layer ◽  
Basal Cell Layer ◽  
Stratified Epithelium ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Cell Layers ◽  
Stratified Epithelia

Multi-layered ("stratified") epithelia differ from one-layered ("simple") polar epithelia by various architectural and functional properties as well as by their cytoskeletal complements, notably a set of cytokeratins characteristic of stratified tissue. The simple epithelial cytokeratins 8 and 18 have so far not been detected in any stratified epithelium. Using specific monoclonal antibodies we have noted, in several but not all samples of stratified epithelia, including esophagus, tongue, exocervix, and vagina, positive immunocytochemical reactions for cytokeratins 8, 18, and 19 which in some regions were selective for the basal cell layer(s) but extended into suprabasal layers in others. In situ hybridization with different probes (riboprobes, synthetic oligonucleotides) for mRNAs of cytokeratin 8 on esophageal epithelium has shown, in extended regions, relatively strong reactivity for cytokeratin 8 mRNA in the basal cell layer. In contrast, probes to cytokeratin 18 have shown much weaker hybridization which, however, was rather evenly spread over basal and suprabasal strata. These results, which emphasize the importance of in situ hybridization in studies of gene expression in complex tissues, show that the genes encoding simple epithelial cytokeratins can be expressed in stratified epithelia. This suggests that continual expression of genes coding for simple epithelial cytokeratins is compatible with the formation of squamous stratified tissues and can occur, at least in basal cell layers, simultaneously with the synthesis of certain stratification-related cytokeratins. We also emphasize differences of expression and immunoreactivity of these cytokeratins between different samples and in different regions of the same stratified epithelium and discuss the results in relation to changes of cytokeratin expression during fetal development of stratified epithelia, in response to environmental factors and during the formation of squamous cell carcinomas.

Isoform-specific expression and function of neuregulin

Development ◽  
1997 ◽  
Vol 124 (18) ◽  
pp. 3575-3586 ◽  
Author(s):  
D. Meyer ◽  
T. Yamaai ◽  
A. Garratt ◽  
E. Riethmacher-Sonnenberg ◽  
D. Kane ◽  
...  
Keyword(s):  
Biological Effects ◽  
Type I ◽  
Mouse Development ◽  
Specific Expression ◽  
Independent Functions ◽  
Cell Growth And Differentiation ◽  
Cranial Ganglia ◽  
And Function

Neuregulin (also known as NDF, heregulin, ARIA, GGF or SMDF), induces cell growth and differentiation. Biological effects of neuregulin are mediated by members of the erbB family of tyrosine kinase receptors. Three major neuregulin isoforms are produced from the gene, which differ substantially in sequence and in overall structure. Here we use in situ hybridization with isoform-specific probes to illustrate the spatially distinct patterns of expression of the isoforms during mouse development. Ablation of the neuregulin gene in the mouse has demonstrated multiple and independent functions of this factor in development of both the nervous system and the heart. We show here that targeted mutations that affect different isoforms result in distinct phenotypes, demonstrating that isoforms can take over specific functions in vivo. Type I neuregulin is required for generation of neural crest-derived neurons in cranial ganglia and for trabeculation of the heart ventricle, whereas type III neuregulin plays an important role in the early development of Schwann cells. The complexity of neuregulin functions in development is therefore due to independent roles played by distinct isoforms.

Molecular cloning and expression of a novel homeobox gene AHox1 of the ascidian, Halocynthia roretzi

Development ◽  
1991 ◽  
Vol 111 (3) ◽  
pp. 821-828
Author(s):  
H. Saiga ◽  
A. Mizokami ◽  
K.W. Makabe ◽  
N. Satoh ◽  
T. Mita
Keyword(s):  
Digestive Tract ◽  
Blot Hybridization ◽  
Amino Acid Level ◽  
Homeobox Gene ◽  
Cloning And Expression ◽  
Northern Blot Hybridization ◽  
Halocynthia Roretzi ◽  
Adult Tissues ◽  
Pharyngeal Epithelium

We have isolated a novel ascidian homeobox gene, designated AHox1, by screening the genomic DNA of Halocynthia roretzi with the Bombyx mori Antennapedia type homeobox as a probe. The AHox1 gene encodes a protein that consists of 741 amino acids. The homeobox of AHox1 is interrupted by 2 introns each of which is about 300 bp in length and it shows about 70% similarity at a deduced amino acid level to that of Drosophila H2.0. This suggests that AHox1 is one of the most diverged homeobox genes so far characterized. Northern blot hybridization with an AHox1 probe showed the presence of single transcripts approximately 2.8 kb in length in larvae, juveniles and some adult tissues. The expression of AHox1 is scarcely detected during the course of early development but it increases to a moderate level at the larval stage. After metamorphosis, the level of AHox1 expression increases as development proceeds. In situ hybridization to the juvenile 7 days after metamorphosis showed that the site of AHox1 expression is the epithelium of digestive tract. Among the adult tissues examined, digestive tract, digestive gland and coelomic cells were the major sites of the expression of AHox1. In gonad, body wall muscle and pharyngeal epithelium, the expression of AHox1 is relatively weak. These results suggest that AHox1 is primarily expressed in the tissues of endodermal origin and that the gene expression may be associated with differentiation of the endodermal tissues.

Post-transcriptional block in oxytocin gene expression within the seminiferous tubules of the bovine testis

1994 ◽  
Vol 140 (1) ◽  
pp. 63-72 ◽  
Author(s):  
H Ungefroren ◽  
M Davidoff ◽  
R Ivell
Keyword(s):  
Gene Expression ◽  
Leydig Cells ◽  
Blot Hybridization ◽  
Seminiferous Tubules ◽  
Transcriptional Level ◽  
Gene Transcript ◽  
Northern Blot Hybridization ◽  
Rnase Protection ◽  
Low Level

Abstract Northern blot hybridization showed that bovine and sheep testis, unlike testes from other mammals, contain moderate levels of an apparently normal oxytocin gene transcript. In situ hybridization localized this mRNA to within the seminiferous tubules, possibly in the Sertoli cells. Conflicting with this result, immunohistochemistry showed that both oxytocin and the syngeneic neurophysin I epitopes are both clearly restricted to the Leydig cells, being expressed here at a low level. Since illegitimate transcription from spurious start sites can lead to a lack of translation product, the integrity of the major ruminant testicular transcripts of the oxytocin gene was checked using differential hybridization, RNase protection and multiple polymerase chain reaction assays. All tests showed the transcripts to have a normal, translatable composition and to be transcribed from the conventional 5' initiation site. Therefore, the block in oxytocin gene expression within the tubules is probably due to a lesion at the post-transcriptional level. The low level peptide expression in the Leydig cells can probably be attributed to the presence of functional transcripts in these cells, which are below the level of significant detection for the in situ hybridization assay. Journal of Endocrinology (1994) 140, 63–72

scholarly journals Gammaproteobacterial Methanotrophs Dominate Cold Methane Seeps in Floodplains of West Siberian Rivers

2014 ◽  
Vol 80 (19) ◽  
pp. 5944-5954 ◽  
Author(s):  
Igor Y. Oshkin ◽  
Carl-Eric Wegner ◽  
Claudia Lüke ◽  
Mikhail V. Glagolev ◽  
Illiya V. Filippov ◽  
...  
Keyword(s):  
West Siberia ◽  
Dry Weight ◽  
Small Rivers ◽  
Type I ◽  
Content Type ◽  
Cell Counts ◽  
Genes Encoding ◽  
Irtysh Basin ◽  
Methane Fluxes

ABSTRACTA complex system of muddy fluid-discharging and methane (CH4)-releasing seeps was discovered in a valley of the river Mukhrinskaya, one of the small rivers of the Irtysh Basin, West Siberia. CH4flux from most (90%) of these gas ebullition sites did not exceed 1.45 g CH4h−1, while some seeps emitted up to 5.54 g CH4h−1. The δ13C value of methane released from these seeps varied between −71.1 and −71.3‰, suggesting its biogenic origin. Although the seeps were characterized by lowin situtemperatures (3.5 to 5°C), relatively high rates of methane oxidation (15.5 to 15.9 nmol CH4ml−1day−1) were measured in mud samples. Fluorescencein situhybridization detected 107methanotrophic bacteria (MB) per g of mud (dry weight), which accounted for up to 20.5% of total bacterial cell counts. Most (95.8 to 99.3%) methanotroph cells were type I (gammaproteobacterial) MB. The diversity of methanotrophs in this habitat was further assessed by pyrosequencing ofpmoAgenes, encoding particulate methane monooxygenase. A total of 53,828pmoAgene sequences of seep-inhabiting methanotrophs were retrieved and analyzed. Nearly all of these sequences affiliated with type I MB, including theMethylobacter-Methylovulum-Methylosomagroup, lake cluster 2, and several as-yet-uncharacterized methanotroph clades. Apparently, microbial communities attenuating methane fluxes from these local but strong CH4sources in floodplains of high-latitude rivers have a large proportion of potentially novel, psychrotolerant methanotrophs, thereby providing a challenge for future isolation studies.

scholarly journals Tissue-Specific Transcriptomes Reveal Gene Expression Trajectories in Two Maturing Skin Epithelial Layers in Zebrafish Embryos

2019 ◽  
Vol 9 (10) ◽  
pp. 3439-3452 ◽  
Author(s):  
Shawn J. Cokus ◽  
Maricruz De La Torre ◽  
Eric F. Medina ◽  
Jeffrey P. Rasmussen ◽  
Joselyn Ramirez-Gutierrez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Basal Cell ◽  
Building Blocks ◽  
Cell Types ◽  
Basal Cells ◽  
Skin Cells ◽  
Genes Encoding ◽  
Cell Layers ◽  
Epithelial Layers

Epithelial cells are the building blocks of many organs, including skin. The vertebrate skin initially consists of two epithelial layers, the outer periderm and inner basal cell layers, which have distinct properties, functions, and fates. The embryonic periderm ultimately disappears during development, whereas basal cells proliferate to form the mature, stratified epidermis. Although much is known about mechanisms of homeostasis in mature skin, relatively little is known about the two cell types in pre-stratification skin. To define the similarities and distinctions between periderm and basal skin epithelial cells, we purified them from zebrafish at early development stages and deeply profiled their gene expression. These analyses identified groups of genes whose tissue enrichment changed at each stage, defining gene flow dynamics of maturing vertebrate epithelia. At each of 52 and 72 hr post-fertilization (hpf), more than 60% of genes enriched in skin cells were similarly expressed in both layers, indicating that they were common epithelial genes, but many others were enriched in one layer or the other. Both expected and novel genes were enriched in periderm and basal cell layers. Genes encoding extracellular matrix, junctional, cytoskeletal, and signaling proteins were prominent among those distinguishing the two epithelial cell types. In situ hybridization and BAC transgenes confirmed our expression data and provided new tools to study zebrafish skin. Collectively, these data provide a resource for studying common and distinguishing features of maturing epithelia.

scholarly journals Glucose represses transcription of Saccharomyces cerevisiae nuclear genes that encode mitochondrial components.

1984 ◽  
Vol 4 (5) ◽  
pp. 939-946 ◽  
Author(s):  
E Szekely ◽  
D L Montgomery
Keyword(s):  
Blot Hybridization ◽  
Beta Subunit ◽  
Alpha Subunit ◽  
Northern Blot Hybridization ◽  
Rich Medium ◽  
Genes Encoding ◽  
Atpase Subunits ◽  
Steady State Levels ◽  
Alpha Beta ◽  
Kinetics Of

By Northern blot hybridization analysis, we demonstrated that the steady-state levels of mRNAs specifying the alpha subunit of ATPase, the beta subunit of ATPase, and the ATP/ADP translocator are all reduced in cells grown in glucose-rich medium. The extent to which glucose represses the levels of alpha, beta, and translocator mRNAs varies from strain to strain, from 2.5- to 7-fold. Furthermore, by hybridization experiments with an excess of DNA, we showed that glucose represses the rates of synthesis of these mRNAs. The kinetics of repression and depression of transcription were also studied. Finally, a mutant was characterized which appears to be defective in depression of transcription of the genes encoding the alpha and beta ATPase subunits as well as the ATP/ADP translocator.

scholarly journals Human salivary cystatin S. Cloning, sequence analysis, hybridization in situ and immunocytochemistry

1991 ◽  
Vol 278 (3) ◽  
pp. 627-635 ◽  
Author(s):  
L A Bobek ◽  
A Aguirre ◽  
M J Levine
Keyword(s):  
Sequence Similarity ◽  
Leader Peptide ◽  
Cdna Clones ◽  
Specific Expression ◽  
Direct Dna Sequencing ◽  
Pcr Products ◽  
Cystatin Gene ◽  
Hybridization In Situ ◽  
Cystatin Sn

A human submandibular-gland (SMG) cDNA library was constructed in a lambda was constructed in a lambda gt11 Sfi-Not orientation-specific expression vector and then screened with antibody generated against human salivary cystatins. The clone C4-4 encoded an N-terminally truncated cystatin S, whereas the others encoded cystatin SN. The library was then rescreened with the C4-4, and the inserts of several positive clones were directly amplified from the eluted plaques by linear PCR and the PCR products analysed by Southern blotting and direct DNA sequencing. Two clones (C3 and C12) encoded a full-length secreted cystatin S and its leader peptide and included 5′- and 3′-untranslated regions. These clones showed a high degree of sequence similarity to cDNA clones encoding human salivary cystatin SN and genomic clones encoding cystatin SN and SA. Hybridization in situ of normal human SMG and parotid-gland (PG) tissue sections localized the cystatin-gene transcripts to the cytoplasm of serous acinar cells of both glands, with a much higher concentration of cystatin mRNA in the SMG. Immunocytochemistry localized the salivary cystatin gene products also to the serous cells, and the levels of cystatin protein correlated with the amount of cystatin mRNA, with a much stronger signal in the SMG than in the PG.

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