scholarly journals Double labeling with non-isotopic in situ hybridization and BrdU immunohistochemistry: calmodulin (CaM) mRNA expression in post-mitotic neurons of the olfactory system.

1992 ◽  
Vol 40 (4) ◽  
pp. 535-540 ◽  
Author(s):  
S Biffo ◽  
L Verdun di Cantogno ◽  
A Fasolo

We describe a novel histochemical procedure for simultaneous detection of mRNA expression by in situ hybridization (ISH) and DNA synthesis on cells that are pulse-labeled with bromodeoxyuridine (BrdU) by immunohistochemistry (ICC). Pregnant rats were injected with BrdU at embryonic Day 20 and the olfactory bulbs of their pups were collected daily. The expression of calmodulin (CaM) mRNA was analyzed by ISH with an anti-sense digoxigenin-labeled riboprobe and BrdU incorporation by indirect ICC. Starting 5 days after BrdU injection, a few tufted and granular neurons of the olfactory bulb were observed to be double labeled for CaM mRNA and BrdU. To study the olfactory neuroepithelium, adult animals were injected with BrdU, sacrificed after 30 days, and the nasal mucosa dissected and decalcified. The co-expression of CaM mRNA and BrdU incorporation was then analyzed in the olfactory neuroepithelium: BrdU-positive primary olfactory neurons were also CaM mRNA positive. The combination of ISH and ICC on the same section resulted in improved BrdU staining with respect to both increased intensity and reduced background levels. The procedure described here can be applied to a variety of problems in developmental biology and is of potential value for correlating the timing of specific mRNA expression with the birth date of a cell type of interest.

1996 ◽  
Vol 44 (3) ◽  
pp. 221-226 ◽  
Author(s):  
A M Gown ◽  
J J Jiang ◽  
H Matles ◽  
M Skelly ◽  
T Goodpaster ◽  
...  

Several different methods of measuring proliferation indices have been developed, including measurements of cellular DNA content (flow cytometry), S-phase incorporation of thymidine analogues into DNA (e.g., tritiated thymidine and 5'-bromodeoxyuridine), and immunostaining of cell cycle-restricted proteins (e.g., Ki-67 antigen and PCNA). Theoretical and practical problems with each method have made it difficult to compare absolute proliferation rates among cells of different lineages and degrees of malignancy. More recently, in situ hybridization (ISH) for histone 3 (H3) mRNA has been introduced. We used a double labeling method for comparing H3 mRNA expression and S-phase incorporation of 5'-bromodeoxyuridine (BrdU) to determine if H3 mRNA expression was tightly associated with S-phase in a variety of malignant and nontransformed cell types. In addition, labeling results were compared in methacarn- and formalin-fixed tissues to extend the potential usefulness of H3 ISH, using a postfixation technique for the alcohol-fixed specimens. As expected for a cumulative marker, variation was noted in the percentage of the BrdU-positive cells double labeled with H3 ISH (53-89%), depending on cell type and length of BrdU incubation. In contrast, the percentage of the H3 ISH-positive cell population double labeled for BrdU was independent of the cell type of BrdU incubation time (mean 78%). Similarly, a consistent percentage of H3 ISH-positive cell populations was double labeled for BrdU in normal tissues (mean 97%). These findings support a well-conserved timing mechanism for H3 mRNA expression and DNA replication. We conclude that H3 ISH is an extremely accurate technique for assessment of S-phase cell proliferation indices.


2002 ◽  
Vol 14 (3) ◽  
pp. 236-240 ◽  
Author(s):  
Junghyun Kim ◽  
Chanhee Chae

A technique for double in situ hybridization to simultaneously detect porcine circovirus 2 (PCV2) and porcine parvovirus (PPV) in the same tissue section was developed and applied to lymph node and spleen from 8 pigs experimentally coinfected with PCV2 and PPV and 20 pigs with naturally occurring postweaning multisystemic wasting syndrome. For double labeling studies, the tissue samples were processed sequentially, first for PPV in situ hybridization using a digoxigenin-labeled probe and then for PCV2 in situ hybridization using a biotinylated probe. Positive cells contained reaction products for PCV2 and PPV, respectively. Both PCV2 DNA and PPV DNA were observed mainly in the cytoplasm but occasionally in the nucleus. With double in situ hybridization, both PCV2 DNA and PPV DNA were simultaneously detected in lymph node and spleen. This double labeling technique for the detection of PCV2 and PPV is suitable both for pathogenesis studies and for diagnostic applications.


1989 ◽  
Vol 108 (6) ◽  
pp. 2343-2353 ◽  
Author(s):  
R H Singer ◽  
G L Langevin ◽  
J B Lawrence

We have been able to visualize cytoskeletal messenger RNA molecules at high resolution using nonisotopic in situ hybridization followed by whole-mount electron microscopy. Biotinated cDNA probes for actin, tubulin, or vimentin mRNAs were hybridized to Triton-extracted chicken embryo fibroblasts and myoblasts. The cells were then exposed to antibodies against biotin followed by colloidal gold-conjugated antibodies and then critical-point dried. Identification of mRNA was possible using a probe fragmented to small sizes such that hybridization of several probe fragments along the mRNA was detected as a string of colloidal gold particles qualitatively and quantitatively distinguishable from nonspecific background. Extensive analysis showed that when eight gold particles were seen in this iterated array, the signal to noise ratio was greater than 30:1. Furthermore, these gold particles were colinear, often spiral, or circular suggesting detection of a single nucleic acid molecule. Antibodies against actin, vimentin, or tubulin proteins were used after in situ hybridization, allowing simultaneous detection of the protein and its cognate message on the same sample. This revealed that cytoskeletal mRNAs are likely to be extremely close to actin protein (5 nm or less) and unlikely to be within 20 nm of vimentin or tubulin filaments. Actin mRNA was found to be more predominant in lamellipodia of motile cells, confirming previous results. These results indicate that this high resolution in situ hybridization approach is a powerful tool by which to investigate the association of mRNA with the cytoskeleton.


1988 ◽  
Vol 66 (8) ◽  
pp. 1113-1121 ◽  
Author(s):  
V. K. M. Han ◽  
A. J. D'Ercole ◽  
D. C. Lee

Transforming growth factors (TGFs) are polypeptides that are produced by transformed and tumour cells, and that can confer phenotypic properties associated with transformation on normal cells in culture. One of these growth-regulating molecules, transforming growth factor alpha (TGF-α), is a 50 amino acid polypeptide that is related to epidermal growth factor (EGF) and binds to the EGF receptor. Previous studies have shown that TGF-α is expressed during rodent embryogenesis between 7 and 14 days gestation. To investigate the cellular sites of TGF-α mRNA expression during development, we have performed Northern analyses and in situ hybridization histochemistry on the conceptus and maternal tissues at various gestational ages. Contrary to previous reports, both Northern analyses and in situ hybridization histochemistry indicate that TGF-α mRNA is predominantly expressed in the maternal decidua and not in the embryo. Decidual expression is induced following implantation, peaks at day 8, and declines through day 15 when the decidua is being resorbed. In situ hybridization revealed that expression of TGF-α mRNA is highest in the region of decidua adjacent to the embryo and is low or nondetectable in the uterus, placenta, and embryo. In addition, we could not detect TGF-α mRNA expression in other maternal tissues, indicating that the induction of TGF-α transcripts in the decidua is tissue specific, and not a pleiotropic response to changes in hormonal milieu that occur during pregnancy. The developmentally regulated expression of TGF-α mRNA in the decidua, together with the presence of EGF receptors in this tissue, suggests that this peptide may stimulate mitosis and angiogenesis locally by an autocrine mechanism. Because EGF receptors are also present in the embryo and placenta, TGF-α may act on these tissues by a paracrine or endocrine mechanism.


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