Genomic organization and expression of the planarian homeobox genes Dth-1 and Dth-2

Development ◽  
1993 ◽  
Vol 118 (1) ◽  
pp. 241-253 ◽  
Author(s):  
J. Garcia-Fernandez ◽  
J. Baguna ◽  
E. Salo
Keyword(s):  
Spatial Distribution ◽  
In Situ Hybridization ◽  
Genomic Organization ◽  
Evolutionary Relationship ◽  
Homeobox Genes ◽  
Genomic Analysis ◽  
Formation Mechanisms ◽  
Specific Cell ◽  
Specific Expression

We have characterized the genomic organization of Dth-1 and Dth-2, planarian homeobox-containing genes, previously described at the cDNA level (J. Garcia-Fernandez, J. Baguna and E. Salo (1991), Proc. Natl. Acad. Sci. USA, 88, 7338–7342). Genomic analysis shows that Dth-1 and Dth-2 genes encode proteins of 533 and 363 amino acids respectively. The open reading frame of Dth-1 is interrupted by two large introns of 8 kb and 12 kb Dth-2 also shows two introns, but these are short (42 bp and 44 bp) and the second interrupts helix III at position 44–45, as is the case with other homeobox genes from such divergent animals as Drosophila, honeybee, C. elegans, ascidians, and mouse, which suggests an ancient evolutionary relationship between these genes. The spatial distribution of transcripts in adult tissues, determined by in situ hybridization, demonstrates that Dth-1 is expressed at a high level in the gastrodermal cells, while Dth-2 is expressed in the peripheral parenchyma, at higher levels in the dorsal than the ventral regions. Their specific spatial distribution suggests a possible role for these homeobox genes in determination and/or differentiation of specific cell types. The expression pattern of both genes is more or less continuous, but in Dth-1 clustered discontinuous labelling in areas surrounding the gastrodermis may indicate a specific expression of this gene in groups of undifferentiated cells (neoblasts) already committed or determined to gastrodermal cell fates. In situ hybridization analysis during early regeneration shows expression only in the postblastema (stump) differentiated areas while no expression has been detected in the undifferentiated blastema, indicating that neither gene has a role in pattern formation mechanisms known to occur at the early stages of regeneration (0-3 days). Hence, Dth-1 and Dth-2 are planarian homeobox genes presumably involved in specific cell or tissue determination and/or differentiation.

Ultrastructural analysis of the spatial distribution of MRNA

1992 ◽  
Vol 50 (1) ◽  
pp. 552-553
Author(s):  
Gary Bassell ◽  
Robert H. Singer
Keyword(s):  
Electron Microscopy ◽  
Spatial Distribution ◽  
In Situ Hybridization ◽  
High Resolution ◽  
Nucleic Acids ◽  
Colloidal Gold ◽  
Dna Probe ◽  
Nucleotide Analogs ◽  
Gold Particles

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.

scholarly journals Localization of type 1 17beta-hydroxysteroid dehydrogenase mRNA and protein in syncytiotrophoblasts and invasive cytotrophoblasts in the human term villi

2000 ◽  
Vol 165 (2) ◽  
pp. 217-222 ◽  
Author(s):  
M Bonenfant ◽  
PR Provost ◽  
R Drolet ◽  
Y Tremblay
Keyword(s):  
In Situ Hybridization ◽  
Hydroxysteroid Dehydrogenase ◽  
Binding Activity ◽  
Placental Lactogen ◽  
Specific Expression ◽  
P450 Aromatase ◽  
Chain Cleavage ◽  
Extravillous Cytotrophoblasts

The 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) play a key role in the synthesis of sex steroids. The hallmark of this family of enzymes is the interconversion, through their oxydoreductive reactivity at position C17, of 17-keto- and 17beta-hydroxy-steroids. Because this reaction essentially transforms steroids having low binding activity for the steroid receptor to their more potent 17beta-hydroxysteroids isoforms, it is crucial to the control of the physiological activities of both estrogens and androgens. The human placenta produces large amounts of progesterone and estrogens throughout pregnancy. The placental type 1 17beta-HSD enzyme (E17beta-HSD) catalyzes the reduction of the low activity estrogen, estrone, into the potent estrogen, estradiol. We studied the cell-specific expression of type 1 17beta-HSD in human term placental villous tissue by combining in situ hybridization to localize type 1 17beta-HSD mRNA with immunohistochemistry using an antibody against human placental lactogen, a trophoblast marker. Immunolocalization of E17beta-HSD was also performed. To ascertain whether other steroidogenic enzymes are present in the same cell type, cytochrome P450 cholesterol side-chain cleavage (P450scc), P450 aromatase, and type 1 3beta-hydroxysteroid dehydrogenase (3beta-HSD) were also localized by immunostaining. Our results showed that the syncytium is the major steroidogenic unit of the fetal term villi. In fact, type 1 17beta-HSD mRNA and protein, as well as P450scc, P450 aromatase, and 3beta-HSD immunoreactivities were found in these cells. In addition, our results revealed undoubtedly that extravillous cytotrophoblasts (CTBs), e.g. those from which cell columns of anchoring villous originate, also express the type 1 17beta-HSD gene. However, CTBs lying beneath the syncytial layer, e.g. those from which syncytiotrophoblasts develop, contained barely detectable amounts of type 1 17beta-HSD mRNA as determined by in situ hybridization. These findings, along with those from other laboratories confirm the primordial role of the syncytium in the synthesis of steroids during pregnancy. In addition, our results indicate for the first time that CTBs differentiating along the invasive pathway contain type 1 17beta-HSD mRNA.

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.

scholarly journals Methods to Enhance Signal Using Isotopic In Situ Hybridization

2002 ◽  
Vol 50 (8) ◽  
pp. 1031-1037 ◽  
Author(s):  
Betty Ky ◽  
Paul J. Shughrue
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Cell Types ◽  
Oxytocin Receptor ◽  
Specific Cell ◽  
Rat Hypothalamus ◽  
Low Levels ◽  
Tuberoinfundibular Peptide ◽  
Cryostat Sections

Isotopic in situ hybridization (ISH) has been established as a uniquely powerful tool for the study of gene expression in specific cell types. This technique allows the visualization and quantification of gene expression and gene expression changes in cells. In our study of biological and molecular phenomena, we have increasingly encountered the need to detect small changes in gene expression as well as genes of low abundance, such as the oxytocin receptor (OTR) and the tuberoinfundibular peptide of 39 residues (Tip39). To increase the sensitivity of isotopic ISH for detection of rare mRNAs, we performed ISH on cryostat sections of rat hypothalamus and thalamus with 35S-labeled riboprobes and amplified the signal by hybridizing over 2 nights as well as labeling the probe with both [35S]-UTP and [35S]-ATP. These two methods of enhancement independently and in combination demonstrated a dramatic increase in signal, allowing the visualization of low levels of gene expression previously undetectable by conventional methods.

scholarly journals Acinar Cells Are Target Cells for Androgens in Mouse Submandibular Glands

1998 ◽  
Vol 46 (5) ◽  
pp. 669-678 ◽  
Author(s):  
Mario Señorale-Pose ◽  
Arnaud Jacqueson ◽  
François Rougeon ◽  
Isabelle Rosinski-Chupin
Keyword(s):  
In Situ Hybridization ◽  
Acinar Cells ◽  
Target Cells ◽  
Parotid Glands ◽  
Specific Expression ◽  
Rnase Protection ◽  
Submandibular Glands ◽  
Androgen Action ◽  
Proline Rich Protein

The variable coding sequence (VCS) multigene family encodes diverse salivary proteins, such as the SMR1 prohormone and the PR-VB1 proline-rich protein in the rat. In situ hybridization was used to study the cell-specific expression of two new mouse VCS genes, Vcs1 and Vcs2. We show that the Vcs1 transcripts, which code for a proline-rich protein, MSG1, are highly abundant in male and female parotid glands, in which they are specifically detected in acinar cells. No expression was seen in the submandibular or sublingual glands. In contrast, Vcs2 transcripts were found only in the acinar cells of the submandibular glands (SMGs) of male mice, in which they are expressed in response to androgens. Expression was found to be heterogeneous within acinar structures. No Vcs2 transcripts were detected in the SMGs of females or castrated males by Northern blot, RNase protection, or in situ hybridization. Androgen administration to females or castrated males induced expression at a level comparable to that of intact males. The Vcs2 gene is the first example of a mouse androgen-regulated gene that is expressed in SMG acinar cells. This result, in addition to our previous observation on SMR1 expression in rats, demonstrates that both acinar cells and granular convoluted tubule (GCT) cells are target cells for androgen action in rodent SMG.

scholarly journals Marine Planktonic Archaea Take Up Amino Acids

2000 ◽  
Vol 66 (11) ◽  
pp. 4829-4833 ◽  
Author(s):  
Cleber C. Ouverney ◽  
Jed A. Fuhrman
Keyword(s):  
Amino Acids ◽  
In Situ Hybridization ◽  
Cell Types ◽  
Similar Proportion ◽  
Specific Cell ◽  
Natural Conditions ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Archaeal Communities

ABSTRACT Archaea are traditionally thought of as “extremophiles,” but recent studies have shown that marine planktonic Archaea make up a surprisingly large percentage of ocean midwater microbial communities, up to 60% of the total prokaryotes. However, the basic physiology and contribution of Archaea to community microbial activity remain unknown. We have studied Archaea from 200-m depths of the northwest Mediterranean Sea and the Pacific Ocean near California, measuring the archaeal activity under simulated natural conditions (8 to 17°C, dark and anaerobic) by means of a method called substrate tracking autoradiography fluorescence in situ hybridization (STARFISH) that simultaneously detects specific cell types by 16S rRNA probe binding and activity by microautoradiography. In the 200-m-deep Mediterranean and Pacific samples, cells binding the archaeal probes made up about 43 and 14% of the total countable cells, respectively. Our results showed that the Archaea are active in the uptake of dissolved amino acids from natural concentrations (nanomolar) with about 60% of the individuals in the archaeal communities showing measurable uptake. Bacteria showed a similar proportion of active cells. We concluded that a portion of these Archaea is heterotrophic and also appears to coexist successfully with Bacteria in the same water.

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