The initiation of basal disc formation in Dictyostelium discoideum is an early event in culmination

Development ◽  
1996 ◽  
Vol 122 (3) ◽  
pp. 753-760 ◽  
Author(s):  
K. Jermyn ◽  
D. Traynor ◽  
J. Williams
Keyword(s):  
Early Event ◽  
Double Staining ◽  
Forward Movement ◽  
Basal Disc ◽  
Stage Of Development ◽  
Glucuronidase Reporter ◽  
Tip Formation ◽  
Beta Galactosidase ◽  
Disc Formation

We have analysed expression of the ecmA and ecmB genes of Dictyostelium by enzymatic double staining using beta-galactosidase and beta-glucuronidase reporter gene constructs. Cells expressing the ecmA gene first appear as scattered cells at the mound stage of development and we show that this is also true for cells expressing the ecmB gene. During tip formation the ecmA-expressing cells move to the apex of the mound, while the ecmB-expressing cells accumulate in the base. The ecmB-expressing cells constitute part of the basal disc if the culminant is formed in situ but are discarded if a migratory slug is formed. During slug migration they are replaced by a band of ecmB-expressing cells, situated in the front half of the prespore zone and tightly apposed to the substratum. When culmination is triggered these cells rapidly move to the back half of the prestalk zone, possibly acting as a point of attachment to the substratum. Ultimately, they are joined by cells at the back of the slug, the rearguard cells, to form the basal disc. Thus, contrary to previous belief, basal disc formation is initiated very early during culmination and occurs by the forward movement of cells located in the anterior of the prespore zone.

scholarly journals Combined beta-galactosidase and immunogold/silver staining for immunohistochemistry and DNA in situ hybridization.

1990 ◽  
Vol 38 (3) ◽  
pp. 325-329 ◽  
Author(s):  
W van den Brink ◽  
C van der Loos ◽  
H Volkers ◽  
R Lauwen ◽  
F van den Berg ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Silver Staining ◽  
Staining Method ◽  
Double Staining ◽  
Reaction Products ◽  
Silver Enhancement ◽  
Silver Staining Method ◽  
Double Staining Method ◽  
Beta Galactosidase

A combination of beta-galactosidase enzyme and the immunogold/silver staining method was studied for evaluation of double-staining experiments. Applications are shown for immunohistochemical double staining using two monoclonal antibodies and for combined immunohistochemistry and DNA in situ hybridization in one tissue section. The following advantages for the present double-staining method were evaluated: superior sensitivity of the immunogold/silver staining method for at least one epitope, which also allows detection of biotinylated DNA probes. The structure of the indolyl precipitate after revelation of beta-galactosidase activity did not show a concealing effect during a sequential double-staining method, as compared with the visualization of peroxidase with diaminobenzidine. These factors, and the sharply contrasting colored reaction products of beta-galactosidase (blue-green) and the immunogold/silver staining method including silver enhancement (brown-black), allow clear distinction of mixed-stained cell constituents.

Inducible expression of an hsp68-lacZ hybrid gene in transgenic mice

Development ◽  
1989 ◽  
Vol 105 (4) ◽  
pp. 707-714 ◽  
Author(s):  
R. Kothary ◽  
S. Clapoff ◽  
S. Darling ◽  
M.D. Perry ◽  
L.A. Moran ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Constitutive Expression ◽  
Heat Shock Gene ◽  
Preimplantation Embryos ◽  
Northern Analysis ◽  
Sequence Information ◽  
Hybrid Gene ◽  
Stage Of Development ◽  
Beta Galactosidase

Transgenic mice have been generated that express the E. coli beta-galactosidase gene under the control of the promoter from the mouse heat-shock gene, hsp68. Sequences from −664 to +113 relative to the start of transcription of the hsp68 gene were sufficient to direct stress-induced expression of the beta-galactosidase gene in adult tail tissue and various tissues of fetal stages of development. Expression was detected in situ by staining with the chromogenic substrate, X-gal. The hybrid gene was refractory to induction in preimplantation embryos until the blastocyst stage of development, as reported for the endogenous hsp68 gene. No constitutive expression was observed by in situ staining or Northern analysis at any stage of development, even in tissues that constitutively express the endogenous hsp68 gene. We conclude that the hsp68 promoter region included in the construct contains sufficient sequence information for heat and arsenite inducibility, but it does not contain sequences controlling tissue-specific expression during development. This tightly regulated inducible promoter may provide a useful tool for short-term inducible gene expression in transgenic mice.

scholarly journals Human kidney is a target for novel severe acute respiratory syndrome coronavirus 2 infection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bo Diao ◽  
Chenhui Wang ◽  
Rongshuai Wang ◽  
Zeqing Feng ◽  
Ji Zhang ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Kidney Injury ◽  
Human Kidney ◽  
The Elderly ◽  
Tubular Damage ◽  
Clinical Parameters ◽  
Double Staining ◽  
Protein Deposits ◽  
Prostaglandin D Synthase

AbstractIt is unclear whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can directly infect human kidney, thus leading to acute kidney injury (AKI). Here, we perform a retrospective analysis of clinical parameters from 85 patients with laboratory-confirmed coronavirus disease 2019 (COVID-19); moreover, kidney histopathology from six additional COVID-19 patients with post-mortem examinations was performed. We find that 27% (23/85) of patients exhibited AKI. The elderly patients and cases with comorbidities (hypertension and heart failure) are more prone to develop AKI. Haematoxylin & eosin staining shows that the kidneys from COVID-19 autopsies have moderate to severe tubular damage. In situ hybridization assays illustrate that viral RNA accumulates in tubules. Immunohistochemistry shows nucleocapsid and spike protein deposits in the tubules, and immunofluorescence double staining shows that both antigens are restricted to the angiotensin converting enzyme-II-positive tubules. SARS-CoV-2 infection triggers the expression of hypoxic damage-associated molecules, including DP2 and prostaglandin D synthase in infected tubules. Moreover, it enhances CD68+ macrophages infiltration into the tubulointerstitium, and complement C5b-9 deposition on tubules is also observed. These results suggest that SARS-CoV-2 directly infects human kidney to mediate tubular pathogenesis and AKI.

Condensation of the chromatin at the membrane of an apoptotic nucleus is not associated with activation of an endonuclease

1993 ◽  
Vol 104 (2) ◽  
pp. 317-326 ◽  
Author(s):  
F. Oberhammer ◽  
G. Fritsch ◽  
M. Schmied ◽  
M. Pavelka ◽  
D. Printz ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Early Event ◽  
Tgf Beta ◽  
Hoechst 33258 ◽  
Nucleolar Structure ◽  
Nuclear Changes ◽  
Rigorous Test ◽  
A Current ◽  
Mouse Lymphoma

A current hypothesis holds that chromatin fragmentation into oligonucleosomal patterns is an early event during apoptosis. In contrast, induction of apoptosis in cultured hepatocytes by TGF-beta 1 was not associated with DNA fragmentation into oligonucleosomes in hepatocyte monolayers and apoptotic fragments. For a more rigorous test of the hypothesis we performed a number of experiments. We compared nuclear changes resulting from TGF-beta 1 with those induced by Ca2+, a known activator of endonuclease. The morphology of apoptotic and Ca(2+)-treated nuclei was different as judged by DNA staining with Hoechst 33258. Likewise, electron microscopy of apoptotic nuclei showed characteristic condensation of the chromatin as well as dissolution of the nucleolar structure and nuclear fragmentation, changes not seen after Ca2+ treatment, after three hours of incubation. Analysis of DNA fluorescence of nuclei by FACS revealed that treatment with Ca2+ reduced the signal by 20%. In contrast, nuclei from TGF-beta 1-treated hepatocytes did not exhibit a reduced signal and after sorting by FACS, apoptotic nuclei remained in the 2N and 4N fractions. The absence of detectable DNA fragmentation in apoptotic nuclei was further verified by in situ nick translation, not only in hepatocytes but also in a mouse lymphoma cell line. From these findings we conclude that activation of an endonuclease is not an early event on the pathway to morphologically recognizable apoptosis.

Morphogenesis in hydra

Development ◽  
1970 ◽  
Vol 24 (1) ◽  
pp. 21-32
Author(s):  
Sondra C. Corff ◽  
Allison L. Burnett
Keyword(s):  
Nervous System ◽  
Cell Division ◽  
Hydrostatic Pressure ◽  
Low Temperature ◽  
Low Temperatures ◽  
Mitotic Division ◽  
Basal Disc ◽  
Dividing Cells ◽  
Short Time ◽  
Disc Formation

When Hydra oligactis is excised below the tentacles and incubated for a short time in concentrations of colchicine that inhibit spindle formation in dividing cells, a peduncle and basal disc subsequently form at the cut distal end, where hypostome and tentacles normally form (Corff & Burnett, 1969). Since recent reports suggest a similarity in the action of colchicine and low temperature, in this study the effects of low temperatures on regenerating hydra were investigated. High hydrostatic pressure and low temperature have been shown to act synergistically with colchicine to inhibit the first mitotic division in sea urchin eggs (Marsland, 1968). Colchicine and cooling have also been shown to cause disintegration of the microtubule system in Actinosphaerium (Tilney, 1965). We have previously discussed peduncle and basal disc formation at the distal end in terms of colchicine inhibition of cell division and the possible action of colchicine on the nervous system (Corff & Burnett, 1969).

Spatial- and temporal-restricted pattern for amelogenin gene expression during mouse molar tooth organogenesis

Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 77-85 ◽  
Author(s):  
M.L. Snead ◽  
W. Luo ◽  
E.C. Lau ◽  
H.C. Slavkin
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Gene Transcription ◽  
Developmental Stages ◽  
Three Dimensional ◽  
Molar Tooth ◽  
Specific Expression ◽  
Amelogenin Gene ◽  
Stage Of Development

Position- and time-restricted amelogenin gene transcription was analysed in developing tooth organs using in situ hybridization with asymmetric complementary RNA probes produced from a cDNA specific to the mouse 26 × 10(3) Mr amelogenin. In situ analysis was performed on developmentally staged fetal and neonatal mouse mandibular first (M1) and maxillary first (M1) molar tooth organs using serial sections and three-dimensional reconstruction. Amelogenin mRNA was first detected in a cluster of ameloblasts along one cusp of the M1 molar at the newborn stage of development. In subsequent developmental stages, amelogenin transcripts were detected within foci of ameloblasts lining each of the five cusps comprising the molar crown form. The number of amelogenin transcripts appeared to be position-dependent, being more abundant on one cusp surface while reduced along the opposite surface. Amelogenin gene transcription was found to be bilaterally symmetric between the developing right and left M1 molars, and complementary between the M1 and M1 developing molars; indicating position-restricted gene expression resulting in organ stereoisomerism. The application of in situ hybridization to forming tooth organ geometry provides a novel strategy to define epithelial-mesenchymal signal(s) which are believed to be responsible for organ morphogenesis, as well as for temporal- and spatial-restricted tissue-specific expression of enamel extracellular matrix.

In situ detection of beta-galactosidase in lenses of transgenic mice with a gamma-crystallin/lacZ gene

Science ◽  
1987 ◽  
Vol 235 (4787) ◽  
pp. 456-458 ◽  
Author(s):  
D. Goring ◽  
J Rossant ◽  
S Clapoff ◽  
M. Breitman ◽  
L. Tsui
Keyword(s):  
Transgenic Mice ◽  
Lacz Gene ◽  
Gamma Crystallin ◽  
In Situ Detection ◽  
Beta Galactosidase

Wall structure and ornamentation of the urediniospores of Uromyces viciae-fabae

1987 ◽  
Vol 65 (10) ◽  
pp. 2007-2016 ◽  
Author(s):  
A. M. Woods ◽  
A. Beckett
Keyword(s):  
Endoplasmic Reticulum ◽  
Chemical Change ◽  
Spore Wall ◽  
Wall Structure ◽  
Colloidal Iron ◽  
Cytochemical Localization ◽  
Enzymic Digestion ◽  
Stage Of Development ◽  
Temperature Scanning

The development of the spines and the structure and composition of the urediniospore wall of Uromyces viciae-fabae have been studied by low-temperature scanning electron microscopy, cytochemical localization, chemical, and enzymic digestion techniques. Spine formation was similar to that previously described for urediniospores of other rust fungi. Swollen collars that are distinct from the annular ridges are only evident in frozen-hydrated spores and surround the bases of spines. Pockets of endoplasmic reticulum line the periphery of spores and mark the sites of spine development. This endoplasmic reticulum may have a role in the production of enzymes and (or) structural proteins or glycoproteins. Microfibrils are present in digested and shadowed wall preparations, often associated with spines. Enzymic digestion treatment suggests that these microfibrils are chitin. Around the bases of the spines, microfibrils are orientated circumferentially and contribute in part to the thickened, annular ridges evident in all spore preparations. The spore wall matrix consists of polysaccharides. Colloidal iron staining indicates acid mucopolysaccharides. Differences in reaction of the urediniospore wall to colloidal iron at what appears to be the same stage of development suggests in situ chemical change(s), which may in turn be linked with changes in wall plasticity.

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