pGLO (plasmid)
pGLO is a trademarked engineered plasmid widely used in genetic research to create genetically modified organisms (GMOs). This plasmid has been specifically designed to include several key genes that serve as markers for scientists. Notably, it contains a gene that provides resistance to the antibiotic ampicillin, allowing researchers to work with bacteria that would typically be susceptible to this antibiotic. Additionally, pGLO incorporates the gene for green fluorescent protein (GFP), which originates from the North American jellyfish Aequorea victoria. This protein emits a bright green glow under ultraviolet light, facilitating the visualization of genetic modifications.
The pGLO plasmid also includes the araC gene, which regulates the expression of GFP, activating it only in the presence of arabinose, a sugar. This feature enables precise control over when the fluorescence occurs, which is crucial for experimental purposes. With its multiple cloning site, pGLO can incorporate various genetic materials, making it a versatile tool in genetic engineering. Its applications have extended beyond bacteria to include experiments with living animals, where it has been used to study genetic functions in a visually impactful manner. The controversial case of Alba, a genetically modified rabbit that glowed under UV light, highlights the ethical discussions surrounding such experiments. Overall, pGLO represents a significant advancement in genetic research, offering powerful means to explore cellular mechanisms and gene functions.
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pGLO (plasmid)
pGLO is a trademarked engineered plasmid used to create genetically modified organisms, or GMOs. A plasmid is a genetic cell structure that can replicate without needing chromosomes; an engineered plasmid is a substance that has been artificially created to do this. GMOs are organisms that have been changed at the genetic level by adding genetic material from another organism.
What is unique about pGLO is that it has been engineered to include several genes that scientists can use to trace it. One addition is a gene that is resistant to the antibiotic ampicillin. Another addition is green florescent protein, or GFP, which is a substance that glows bright green under ultraviolet light. This makes it easy for scientists to see how pGLO affects GMOs.
Overview
GFP is a naturally-occurring substance found in a specific type of jellyfish: the North American Aequorea victoria. This jellyfish is one of more than one hundred species of animals that are bioluminescent, or biologically equipped to glow on its own. Lightning bugs are another example. Scientists have learned ways to use these biological substances as "tags" that let them see how cells and other organisms work by attaching them to different genetic material.
Japanese chemist Osamu Shimomura was able to isolate the gene that carries GFP in the 1960s. During the 1990s, American scientists Martin Chalfie and Roger Tsein were able to enhance GFP so that it lasted longer, glowed brighter, and could be made in different colors. This made it a powerful tool for scientists to trace genetic material as they were working with it and earned the three men the 2008 Nobel Prize in chemistry.
In addition to GFP, pGLO includes two other genes: araC, which controls the display of the GFP and allows it to be seen only in the presence of arabinose, a type of sugar; and Bla, which makes it resistant to ampicillin. This allows pGLO to be used in bacteria that normally would be killed by ampicillin. It also has a multiple cloning site at the end of the gene, which allows it to be introduced to different types of genetic materials.
pGLO has been used in several types of genetic materials, including some in living animals. This allows scientists to study how specific areas of these organisms function, as if a light has been shined on them from inside. It is similar to the way contrast agents are used during a study of the gastrointestinal system to see how the digestive system works.
One famous and controversial test done using pGLO involved French scientists and an albino rabbit named Alba. Before Alba was born, pGLO was injected into the fertilized egg. This resulted in Alba glowing green under ultraviolet light, especially around her eyes and ears. Alba made international news in 2000 but died in August of 2002. The scientists denied that the experiment had anything to do with her death. Other animals, including frogs, also have been made to glow for experimental reasons using pGLO and the bioluminescent properties of GFP.
Bibliography
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