What is Gene Expression?
Gene expression at its core is just the process of regulating genes and whether they are turned on or off. Having a gene on or off depends on many different things, such as where the cell is in its development, if the cell is infected with a disease, or even the amount of food a cell has can regulate gene expression. Gene expression depends upon the environment the cell is in, in certain cases a gene can be induced when a certain type of protein is needed in the cell. Through the process of Transcription DNA is converted to RNA and then through the process of Translation RNA encodes a specific protein for the cell.
Image Credit_
You can see the Exons/Introns on the top which are manipulated through a process called splicing which cuts out the introns and joins the exons. Then in RNA through RNA splicing or alternative splicing the RNA is manipulated more and then finally exported to the cytoplasm after an poly a tail is added and a guanosine cap is added.
GEO Profiles
No GEO profiles on POLG
RNA Interference (RNAi)
RNAi is the process in which RNA molecules inhibit gene expression that would have otherwise been functioning. Researchers use this to effectively turn off a gene and study the resulting phenotype. The video below will explain more about how RNAi functions and its uses in research.
Analysis
From using FLyBase, Wormbase, and the Mouse Database (MGI) I found similar phenotypes to those observed in Alpers-Huttenlocher Syndrome. The mouse database showed that complete knockout of the POLG gene resulted in embryonic lethality and an inability to come to full term which was also observed in the worm models as well. We would assume this is correct and makes sense because without this gene there would be no encoding region for the alpha subunit of the Polymerase gamma which would result in problems with formation of the DNA polymerase complex in the mitochondria. Some unpredicted results came in the one of the mutant POLG genes in mice where tumor formation occurred and spread rampantly throughout the mouse. This is not a observed phenotype in humans but could lead to some interesting research regarding the gene.
References
- "Gene Expression." Nature.com. Nature Publishing Group, n.d. Web. 23 Mar. 2015.
- "Gene DmelDNApol-γ35." FlyBase Gene Report: DmelDNApol-γ35. FlyBase, n.d. Web. 24 Mar. 2015.
- "RNA Interference." Nature.com. Nature Publishing Group, n.d. Web. 26 Mar. 2015.
- "Polg MGI Mouse Gene Detail - MGI:1196389 - Polymerase (DNA Directed), Gamma." Polg MGI Mouse Gene Detail - MGI:1196389 - Polymerase (DNA Directed), Gamma. MGI, n.d. Web. 19 Mar. 2015.
- "Cochlea Response to Mitochondrial DNA Mutations." NCBI. U.S. National Library of Medicine, n.d. Web. 26 Mar. 2015.