This web page was produced as an assignment for Genetics 564, an undergraduate capstone course at UW-Madison.
What is Homology?
Homology is study of the shared ancestry between structures, genes, or proteins. Homology is inferred when two or more units share more similarity than can be expected by random chance. This excess similarity is explained by common ancestry between the two items. A classic example of homology in biology is the mammalian forelimb. The similar structures are due to the forelimb arising in a common ancestor to all mammals. Though, each species has adapted this similar structure to suite its needs, the similarities are still evident. [1]
How do scientists classify homologous genes?
Homologs are any genes that share a common ancestor. There are two different types of homologs, orthologs and paralogs. Orthologs are homologous genes in different species that arise at the formation of a new species. Paralogs are genes that arise from a duplication of the ancestor gene. [2]
Homologs are any genes that share a common ancestor. There are two different types of homologs, orthologs and paralogs. Orthologs are homologous genes in different species that arise at the formation of a new species. Paralogs are genes that arise from a duplication of the ancestor gene. [2]
Hepatic Triacylglycerol Lipase Homologs
Paralogs
Human
Homo sapiens
Homo sapiens
Orthologs
Pig
Sus scrofa |
Dog
Canis lupus familiaris |
Rabbit
Oryctalogus cuniculus |
Mouse
Mus musculus |
Zebrafish
Danio rerio
Danio rerio
FASTA Sequences for Homologous Proteins
human_lipc_orthologues_common_model_organisms.txt | |
File Size: | 3 kb |
File Type: | txt |
Conclusions
Homology analyses can be useful in many different areas of proteomics. Knowing which organisms contain a homologous protein to hepatic triacylglycerol lipase (HTGL) allows scientists to pick a good model organism for studying diseases. Using sequence homology, we can infer structural and functional similarities between related proteins. Hepatic triacylglycerol lipase has many homologous proteins both within humans and other species. This is beneficial as there are plenty of potential model organisms for studying hepatic lipase deficiency.
References
[1] Britannica, T. E. (2016, September 08). Homology. Retrieved from https://www.britannica.com/science/homology-evolution
[2] Koonin, E. V. (2005). Orthologs, Paralogs, and Evolutionary Genomics. Annual Review of Genetics,39(1), 309-338. doi:10.1146/annurev.genet.39.073003.114725
Non-linked Figures:
Header: https://en.wikipedia.org/wiki/Multiple_sequence_alignment
[2] Koonin, E. V. (2005). Orthologs, Paralogs, and Evolutionary Genomics. Annual Review of Genetics,39(1), 309-338. doi:10.1146/annurev.genet.39.073003.114725
Non-linked Figures:
Header: https://en.wikipedia.org/wiki/Multiple_sequence_alignment