The GUS reporter system (GUS: beta-glucuronidase) is a reporter gene system, particularly useful in plant molecular biology. ^[1] Several kind of GUS reporter gene assay are actually available, depending of the substrate used: the term GUS staining refers to the most common of these, an histochemical technique. Glucuronidase is a lysosomal glycosidase, a type of enzyme that removes carbohydrate groups from proteins. ... In molecular biology, a reporter gene (often simply reporter) is a gene that researchers attach to another they wish to study in cell culture, animals or plants. ... Molecular biology is the study of biology at a molecular level. ... Reporter gene assay is an analysis method that allows the identification of promoters and enhancers and the study of the correlations between their activities and conformations by checking the amount of the reporter proteins that are expressed from reporter genes. ...

Purpose

The purpose of this technique is to analyze the activity of a promoter (in terms of expression of a gene under that promoter) either in a quantitative way or through visualization of its activity in different tissues. The technique is based on beta-glucuronidase, an enzyme from the bacterium Escherichia coli;^[2] the ability of this enzyme to convert a colorless or not fluorescent substrate to a coloured or fluorescent product is the key of the assay.^[3] In genetics, a promoter is a DNA sequence that enables a gene to be transcribed. ... Gene expression, also called protein expression or often simply expression is the process by which a genes DNA sequence is converted into the structures and functions of a cell. ... Look up Tissue on Wiktionary, the free dictionary The word tissue has several meanings: Aerial tissu is an acrobatic art form, and is one of the circus arts. ... Glucuronidase is a lysosomal glycosidase, a type of enzyme that removes carbohydrate groups from proteins. ... Binomial name Escherichia coli T. Escherich, 1885 E. coli at 10,000x magnification Escherichia coli, usually abbreviated to E. coli, discovered by Theodor Escherich, a pediatrician and bacteriologist, is one of the main species of bacteria that live in the lower intestines of warm-blooded animals, including birds and mammals. ... The word substrate can mean the following: In biochemistry, a substrate is a molecule which is acted upon by an enzyme. ... Color is an important part of the visual arts. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ...

Substrates

There are actually different possible glucuronides that can be used as substrates for the beta-glucuronidase, depending on the type of detection needed (histochemical, spectrophotometrical, fluorimetrical). The most common substrate for GUS hystochemical staining is 5-bromo-4-chloro-3-indolyl glucuronide (X-Gluc): the product of the reaction is in this case a clear blue color. Other common substrates are p-nitrophenyl β-D-glucuronide for the spectrophotometrical assay and 4-methylumbelliferyl-beta-D-glucuronide (MUG) for the fluorimetrical assay.^[4] Glucuronide is a substance produced by attaching glucuronic acid to another substance with glycosidic bonds. ... A thin section of lung tissue stained with hematoxylin and eosin. ... In physics, spectrophotometry is the quantitative study of spectra. ...

History

The system was originally developed by Richard Anthony Jefferson during his Ph.D. at the University of Colorado, Boulder. ^[5] He adapted the technique for the use with plants as he worked in the Plant Breeding Institute of Cambridge, between 1985 and 1987 ^[1]. Since then thousands of labs made use of the system, making probably the most widely used tool in plant molecular biology, as underlined by over 6000 citations in scientific literature. ^[5] Richard Anthony Jefferson (b. ... Doctor of Philosophy (Ph. ... The University of Colorado (CU) System consists of five campuses: University of Colorado at Boulder University of Colorado at Colorado Springs University of Colorado at Denver University of Colorado Health Sciences Center Fitzsimons campus of the University of Colorado Health Sciences Center, scheduled to open in 2007 in Aurora, Colorado... Map of the Cambridgeshire area (1904) The city of Cambridge is an old English university town and the administrative centre of the county of Cambridgeshire. ... This article is about the year. ... 1987 (MCMLXXXVII) was a common year starting on Thursday of the Gregorian calendar. ...

Target organisms

An organism is suitable for a GUS assay if it has no own beta-glucuronidase or the own activity is very low (background activity). For this reason the assay is not useful in almost all vertebrates and many molluscs.^[4] As in higher plants, mosses, algae, ferns, fungi and most bacteria there is no detectable GUS activity, ^[4] these organisms are perfectly suitable for the assay and this is the reason why the assay is widespread in plant science. Typical classes Petromyzontidae (lampreys) Placodermi - extinct Chondrichthyes (cartilaginous fish) Acanthodii - extinct Actinopterygii (ray-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Amphibia (amphibians) Reptilia (reptiles) Aves (birds) Mammalia (mammals) Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... Classes Caudofoveata Aplacophora Polyplacophora - Chitons Monoplacophora Bivalvia - Bivalves Scaphopoda - Tusk shells Gastropoda - Snails and Slugs Cephalopoda - Squids, Octopuses, etc. ... The spermatophytes (also known as phanerogams) comprise those plants that produce seeds. ... This is an article about the plant. ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Ferns could be the plural of fern, a type of plant that reproduces using spores rather than seeds. ... Divisions Chytridiomycota Zygomycota Ascomycota Basidiomycota The Fungi (singular: fungus) are a large group of organisms ranked as a kingdom within the Domain Eukaryota. ... Subgroups Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular: bacterium) are a major group of living organisms. ...

Other reporter systems

The GUS system is not the only available gene reporter system for the analysis of promoter activity. Other competing systems are based on e.g. luciferase, GFP, beta-galactosidase, chloramphenicol acetyltransferase (CAT), alkaline phosphatase. The use of one or the other system is mainly dependant on the organism of interest. Luciferase is a generic name for enzymes commonly used in nature for bioluminescence. ... The initialism GFP may refer to Green fluorescent protein, a fluorescent marker frequently used in biology. ... Lactase (or β-galactosidase) is the enzyme involved in the hydrolysis of lactose to galactose and glucose. ... Chloramphenicol acetyltransferase is a bacterial enzyme that detoxifies the antibiotic chloramphenicol. ... Alkaline phosphatase, drawn from PDB 1ANI. Alkaline phosphatase (ALP) (EC 3. ...

Other uses

The GUS assay, as well as other reporter gene systems, can be use for other kind of studies other than the classical promoter activity assay. Reporter systems has been used for the determination of the efficiency of gene delivery systems, the intracellular localization of a gene product, the detection of protein-protein or protein-DNA interactions, the efficiency of translation initiation signals and the success of molecular cloning efforts.

Intellectual Property

The use of the uidA gene for the GUS assay is covered by U.S. Patent 5,268,463, U.S. Patent 5,432,081 and U.S. Patent 5,599,670.

Sources

1. ^ ^a b GUS fusions: beta-glucuronidase as a sensitive and versatile gene fusion marker in higher plants. R.A. Jefferson, T. A. Kavanagh, and M. W. Bevan EMBO J. 1987 December 20; 6(13): 3901–3907 [1]
2. ^ Cloning and endonuclease restriction analysis of uidA and uidR genes in Escherichia coli K-12: determination of transcription direction for the uidA gene. C. Blanco, P. Ritzenthaler, and M. Mata-Gilsinger J Bacteriol 1982 February; 149(2): 587–594. [2]
3. ^ beta-Glucuronidase from Escherichia coli as a gene-fusion marker. R.A. Jefferson, S.M. Burgess, and D. Hirsh PNAS 1986 November; 83(22): 8447–8451 [3]
4. ^ ^a b c U.S. Patent 5,268,463
5. ^ ^a b Cambia Organization Website: biography of Richard A. Jefferson