This web page was produced as an assignment for Genetics 564, an undergraduate capstone course at UW-Madison.
What is Homology?
Homology is defined as the similarity between structures of organisms in different taxa that derives from similar structures in their shared ancestry. Homology can range from similar sequences in DNA or proteins all the way to similar structures regarding entire limbs or organ systems. An important distinction must be noted that homology only refers to similarities between common ancestors, and other similar structures not belonging to said common ancestor are not considered homologous. Homologs refer to genes that have shared sequences between species and were passed down via a common ancestor. There are two different types of homologs. Orthologs are homologs created by speciation events, with similar sequences being passed on from the common ancestor despite differing species. Paralogs refer to gene sequences that are similar because they derive from a duplication event. [1]For example, TMC6 and TMC8 are defined as paralogs. By using homologous genes in model species we are able to study the gene and protein's effects with the many benefits of model species, as well as the reduction of risk that comes with studying genes in humans.
TMC6 Homologs in Common Species
Homo sapiens
(Human) Protein: TMC6 Accession: NP_009198 Length = 805 aa Identity = 100% Canus lupis familiaris
(Dog) Protein: TMC6 Accession: XP_022279603 Length = 813 aa Identity = 76.45% |
Mus musculus
(Mouse) Protein: TMC6 Accession: NP_663414 Length = 810 aa Identity = 75% Danio rerio
(Zebrafish) Protein: TMC6 Accession: XP_017210326 Length = 726 aa Identity = 38.11% Bos taurus
(Cattle) Protein: TMC6 Accession: NP_001068676 Length = 769 aa Identity = 77.47% |
Caenorhabditis elegans
(Roundworm) Protein: TMC1 Accession: NP_508221 Length = 1285 aa Identity = 26% Pan troglodytes
(Chimpanzee) Protein: TMC6 Accession: XP_016788496 Length = 805 aa Identity = 98.76% |
Sources:
1. New World Encyclopedia. (n.d.). Homology (biology). <http://www.newworldencyclopedia.org/entry/Homology_(biology)>
Figures:
https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwidqY6X6IDhAhUF1oMKHTyLBOgQjhx6BAgBEAM&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3AGegenbaur_1870_han d_homology.png&psig=AOvVaw31M1nm-HREcLsO7CHDJn7G&ust=1552624779683180
1. New World Encyclopedia. (n.d.). Homology (biology). <http://www.newworldencyclopedia.org/entry/Homology_(biology)>
Figures:
https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwidqY6X6IDhAhUF1oMKHTyLBOgQjhx6BAgBEAM&url=https%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3AGegenbaur_1870_han d_homology.png&psig=AOvVaw31M1nm-HREcLsO7CHDJn7G&ust=1552624779683180