scholarly journals Cloning and developmental expression of Sna, a murine homologue of the Drosophila snail gene

Development ◽  
1992 ◽  
Vol 116 (1) ◽  
pp. 227-237 ◽  
Author(s):  
M.A. Nieto ◽  
M.F. Bennett ◽  
M.G. Sargent ◽  
D.G. Wilkinson

The genetic analysis of dorsoventral patterning in Drosophila has identified a zinc-finger gene, snail, that is required for mesoderm formation. The cloning and nuclease protection analysis of a Xenopus homologue of this gene has suggested a possible role in the mesoderm of vertebrates. Here, we describe the cloning of a murine homologue of snail, Sna, and in situ hybridisation studies of its developmental expression. Sequence analysis reveals substantial conservation of the second to fifth zinc fingers, but not of the first zinc finger in the Sna gene. Expression occurs in the ectoplacental cone, parietal endoderm, embryonic and extraembryonic mesoderm, in neural crest and in condensing precartilage. Based on the timing and spatial restriction of expression in embryonic mesoderm, we suggest that Sna might be required for the early development of this tissue, as is the case for its Drosophila counterpart. In addition, we propose that Sna might have an analogous role in the development of neural crest. The expression in condensing precartilage indicates that this gene also has a later function in chondrogenesis.

Development ◽  
1992 ◽  
Vol 114 (3) ◽  
pp. 805-813
Author(s):  
A. Rowe ◽  
J.M. Richman ◽  
P.M. Brickell

Retinoic acid causes a range of embryonic defects, including craniofacial abnormalities, in both birds and mammals and is believed to have a number of roles in normal development. We have previously shown that the distribution of retinoic acid receptor-beta (RAR-beta) transcripts is spatially restricted within the neural-crest-derived upper beak primordia of the chick embryo. We have now used in situ hybridisation to trace the distribution of RAR-beta transcripts during the migration of cranial neural crest cells and during formation of these primordia. RAR-beta transcripts were present in a subset of migrating neural-crest-derived cells in the head of the stage 10 embryo. These cells were situated in pathways followed by cells that migrate from the neural crest overlying the posterior prosencephalic/anterior mesencephalic region of the developing brain. Cells containing RAR-beta transcripts accumulated around the developing eyes and in the regions of the ventral head from which the upper beak primordia later develop. We mapped the distribution of RAR-beta transcripts as the facial primordia were forming, with particular reference to the development of the maxillary primordia. We found that these form in a region of the ventral head that includes the boundary between regions of high and low levels of RAR-beta transcripts. The boundary between these two groups of cells persisted as the maxillary primordia developed.(ABSTRACT TRUNCATED AT 250 WORDS)


2012 ◽  
Vol 107 (01) ◽  
pp. 158-166 ◽  
Author(s):  
Silja Vorjohann ◽  
Frédérique Béna ◽  
Alexandre Fort ◽  
Richard J. Fish ◽  
Marguerite Neerman-Arbez

SummaryThe zebrafish is a model organism for studying vertebrate development and many human diseases. Orthologues of the majority of human coagulation factors are present in zebrafish, including fibrinogen. As a first step towards using zebrafish to model human fibrinogen disorders, we cloned the zebrafish fibrinogen cDNAs and made in situ hybridisations and quantitative reverse transcription-polymerase chain reactions (qRT-PCR) to detect zebrafish fibrinogen mRNAs. Prior to liver development or blood flow we detected zebrafish fibrinogen expression in the embryonic yolk syncytial layer and then in the early cells of the developing liver. While human fibrinogen is encoded by a three-gene, 50 kilobase (kb) cluster on chromosome 4 (FGB-FGA-FGG), recent genome assemblies showed that the zebrafish fgg gene appears distanced from fga and fgb, which we confirmed by in situ hybridisation. The zebrafish fibrinogen Bβ and γ protein chains are conserved at over 50% of amino acid positions, compared to the human polypeptides. The zebrafish Aα chain is less conserved and its C-terminal region is nearly 200 amino acids shorter than human Aα. We generated transgenic zebrafish which express a green fluorescent protein reporter gene under the control of a 1.6 kb regulatory region from zebrafish fgg. Transgenic embryos showed strong fluorescence in the developing liver, mimicking endogenous fibrinogen expression. This regulatory sequence can now be used for overexpression of transgenes in zebrafish hepatocytes. Our study is a proof-of-concept step towards using zebrafish to model human disease linked to fibrinogen gene mutations.


Development ◽  
1993 ◽  
Vol 119 (4) ◽  
pp. 1203-1215 ◽  
Author(s):  
C. Thisse ◽  
B. Thisse ◽  
T.F. Schilling ◽  
J.H. Postlethwait

Mesoderm formation is critical for the establishment of the animal body plan and in Drosophila requires the snail gene. This report concerns the cloning and expression pattern of the structurally similar gene snail1 from zebrafish. In situ hybridization shows that the quantity of snail1 RNA increases at the margin of the blastoderm in cells that involute during gastrulation. As gastrulation begins, snail1 RNA disappears from the dorsal axial mesoderm and becomes restricted to the paraxial mesoderm and the tail bud. snail1 RNA increases in cells that define the posterior border of each somite and then disappears when somitic cells differentiate. Later in development, expression appears in cephalic neural crest derivatives. Many snail1-expressing cells were missing from mutant spadetail embryos and the quantity of snail1 RNA was greatly reduced in mutant no tail embryos. The work presented here suggests that snail1 is involved in morphogenetic events during gastrulation, somitogenesis and development of the cephalic neural crest, and that no tail may act as a positive regulator of snail1.


Gut ◽  
1998 ◽  
Vol 42 (2) ◽  
pp. 220-226 ◽  
Author(s):  
C J Reid ◽  
A Harris

Background and aims—Mucin glycoproteins play a key role in the normal function of the epithelium lining the gastrointestinal tract. The expression of mucin genes, MUC 3, 4, 5AC, 5B, 6, 7, and 8 in human fetal tissues was examined to establish the localisation and age of onset of expression of each mucin gene during human development.Methods—Mucin gene expression was assayed by mRNA in situ hybridisation.Results—Expression of MUC3 was detected in the small intestine and colon from 13 weeks gestation onwards and at low levels in the main pancreatic duct at 13 weeks only. MUC4 expression was seen at a low level in the colonic epithelium from 13 weeks of gestation but not elsewhere in the gastrointestinal tract. MUC5AC mRNA was detected in the colon at 17 weeks and at high levels in the stomach at 23 weeks. MUC6transcripts were evident in the pancreatic ducts from 13 weeks of gestation and at high levels in the stomach at 23 weeks.MUC5B, MUC7, and MUC8transcripts were not detected.Conclusions—Mucin genes are expressed from the early mid-trimester of gestation in the developing human fetal gastrointestinal tract.


1999 ◽  
Vol 39 (6) ◽  
pp. 13-20 ◽  
Author(s):  
Philip L. Bond ◽  
Jürg Keller ◽  
Linda L. Blackall

Culturing bacteria from activated sludge with enhanced biological phosphorus removal (EBPR) has strongly implicated Acinetobacter with the process. However, using fluorescent in-situ hybridisation (FISH) probing to analyse microbial populations, we have shown evidence opposing this widespread belief. We describe the phosphorus (P) removing performance and microbial population analyses of sludges obtained in a laboratory scale EBPR reactor. Two sludges with extremely high P removing capabilities were examined, the P content of these sludges was 8.6% (P sludge) and 12.3% (S sludge) of the MLSS. Identification of bacteria using FISH probing indicated both sludges were dominated by microbes from the beta proteobacteria and high mol% G+C Gram positive bacteria. Acinetobacter could make up only a small proportion of the cells in these sludges. Sludge with extremely poor P removal (P content of 1.5%, referred to as T sludge) was then generated by reducing the P in the influent. Bacteria resembling the G-bacteria became abundant in this sludge and these were identified using FISH probing. The anaerobic transformations of the T and P sludges correlated well with that of the non-EBPR and EBPR biological models respectively, indicating that bacteria in the T sludge have the potential to inhibit P removal in EBPR systems.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 250
Author(s):  
Rebecca E O’Connor ◽  
Lucas G Kiazim ◽  
Claudia C Rathje ◽  
Rebecca L Jennings ◽  
Darren K Griffin

With demand rising, pigs are the world’s leading source of meat protein; however significant economic loss and environmental damage can be incurred if boars used for artificial insemination (AI) are hypoprolific (sub-fertile). Growing evidence suggests that semen analysis is an unreliable tool for diagnosing hypoprolificacy, with litter size and farrowing rate being more applicable. Once such data are available, however, any affected boar will have been in service for some time, with significant financial and environmental losses incurred. Reciprocal translocations (RTs) are the leading cause of porcine hypoprolificacy, reportedly present in 0.47% of AI boars. Traditional standard karyotyping, however, relies on animal specific expertise and does not detect more subtle (cryptic) translocations. Previously, we reported development of a multiple hybridisation fluorescence in situ hybridisation (FISH) strategy; here, we report on its use in 1641 AI boars. A total of 15 different RTs were identified in 69 boars, with four further animals XX/XY chimeric. Therefore, 4.5% had a chromosome abnormality (4.2% with an RT), a 0.88% incidence. Revisiting cases with both karyotype and FISH information, we reanalysed captured images, asking whether the translocation was detectable by karyotyping alone. The results suggest that chromosome translocations in boars may be significantly under-reported, thereby highlighting the need for pre-emptive screening by this method before a boar enters a breeding programme.


Author(s):  
Shi-Xun Lu ◽  
Yu-Hua Huang ◽  
Li-Li Liu ◽  
Chris Zhiyi Zhang ◽  
Xia Yang ◽  
...  

Abstract Background Pathologic diagnosis of hepatocellular carcinoma (HCC) can be challenging in differentiating from benign and non-hepatocytic malignancy lesions. The aim of this study was to investigate the potential utility of α-fetoprotein (AFP) mRNA RNAscope, a sensitive and specific method, in the diagnosis of HCC. Methods Three independent retrospective cohorts containing 2216 patients with HCC, benign liver lesions, and non-hepatocytic tumours were examined. AFP was detected using ELISA, IHC (Immunohistochemistry), and RNAscope. Glypican3 (GPC3), hepatocyte paraffin-1 (HepPar-1), and arginase-1 (Arg-1) proteins were detected using IHC. Results AFP RNAscope improved the HCC detection sensitivity by 24.7–32.7% compared with IHC. In two surgical cohorts, a panel of AFP RNAscope and GPC3 provided the best diagnostic value in differentiating HCC from benign hepatocytic lesions (AUC = 0.905 and 0.811), and a panel including AFP RNAscope, GPC3, HepPar-1, and Arg-1 yielded the best AUC (0.971 and 0.977) when distinguishing HCC from non-hepatocytic malignancies. The results from the liver biopsy cohort were similar, and additional application of AFP RNAscope improved the sensitivity by 18% when distinguishing HCC from benign hepatocytic lesions. Conclusions AFP mRNA detected by RNAscope is highly specific for hepatocytic malignancy and may serve as a novel diagnostic biomarker for HCC.


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