This web page was produced as an assignment for Genetics 564, an undergraduate course at UW-Madison. http://genetics564.weebly.com/
DNA Homology
What is DNA homology?
DNA homology is defined as the degree of DNA hybridization capable between two different organisms (1). In other words, DNA homology occurs between organisms with similar DNA sequences.
Homology requires a shared ancestry between the two organisms. This homology can refer to pairs of genes or structures in different species. For example, homologous structures in species with a shared ancestor can be derived into different forms of the structure. In the picture to the right you can see that the different colors in the bones represent the different derivations of each bone. Therefore, all the bones were derived from the same original structure. Homology is often used in evolution to address different adaptations organisms have to their environment. DNA homology additionally denotes a shared gene sequence that represents descent from a common ancestor. The DNA homologs of PTPN2 are shown below. |
PTPN2 DNA Homologs
Some DNA homologs that show a great deal of conservation between human PTPN2 are presented below. This conservation makes makes them great organisms to further investigate PTPN2's role in Crohn's Disease. Specifically the frog, the zebrafish, and the fruitfly are all well-studied, simple model organisms that can be easily manipulated to further investigate the effects of PTPN2 dysfunction. Investigating PTPN2 with these simple model organisms can greatly progress Crohn's Disease research on humans because of the model organisms' high conservation to human PTPN2.
Chimpanzee
(Pan troglodytes) Protein name: PTPN2 Accession #: XM_003953237.1 Identity: 99% |
Cow
(Bos taurus) Protein Name: PTPN2 Accession #: NM_001035431.2 Identity: 98% |
Mouse
(Mus Musculus) Protein name: PTPN2 Accession #: NM_001127177.1 Identity: 82% |
Chicken
(Gallus gallus) Protein name: PTPN2 Accession #: NM_001199387.1 Identity: 78% |
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Frog
(Xenopus tropicalis) Protein name: PTPN2 Accession # NW_004668239.1 Identity: 69% Fruit Fly
(Drosophila melanogaster) Protein name: Ptp61F Accession #: NM_057339.5 Identity: 50% |
Zebrafish
(Danio rerio) Protein name: ptpn2b Accession #: NM_212654.1 Identity: 64% |
Analysis
DNA homology is a great experimental tool for analyzing specific gene's functions more closely in other organisms. It is often very difficult to manipulate and survey gene's effects in humans, so using a DNA homolog to your human gene can allow you to explore the gene further. In particular, using well-studied model organisms like Drosophila and zebrafish can aid in your research. I used the fruit fly (drosophila) to discover and target PTPN2's interactor's phosphorylation targets. The fruit fly is easy to manipulate and had been previously used to investigate PTPN2 so its homolog served as a very crucial part of my specific aims.
References
1. http://www.medilexicon.com/medicaldictionary.php?t=41377