Homology

This web page was produced as an assignment for Genetics 677, an Undergraduate course at UW-Madison

Homology in genetics often refers to the similarity in gene sequence. Similarity in gene sequences can arise due to a common ancestor or not, such as chance or common function. However, homologous genes usually refer to common ancestry. Similar regions among genes are considered to be regions of conservation. Using web databases, homology among both genes and proteins can be measured. Various algorithms are used to give a percent max identify value. I used Homologene to measure the homology of both the FBN1 gene and protein in various organisms.

FBN1 Homologs

Pan troglodytes (Chimpanzee)
Name: Fibrillin 1
Abbreviation: FBN1
Locus: Chromosome 15
Protein Length: 3004 aa
Gene Accession Number: NC_006482.2
Protein Accession Number: XP_001149266.1
                Identity: 99%
                E-Value: 0.0

Canis lupis familiaris (Dog)
Name: Fibrillin 1
Abbreviation: FBN1
Locus: Chromosome 30
Protein Length: 2872 aa
Gene Acession Number: NC_006612.2
Protein Acession Number: XP_861792.1
              Identity: 96%
               E-Value: 0.0

Bos taurus (Cow)
Name: Fibrillin 1
Abbreviation: FBN1
Locus: Chromosome 10
Protein Length: 2871 aa
Gene Accession Number: NC_007308.3
Protein Accession Number: NP_776478.1
               Identity: 97%
               E-Value: 0.0

Mus musculus (Mouse)
Name: Fibrillin 1
Abbreviation: FBN1
Locus: Chromosome 2
Protein Length: 2873 aa
Gene Accession Number: NC_000068.6
Protein Accession Number: NP_032019.2
                Identity: 96%
                E-Value: 0.0

Rattus norvegivcus (Rat)
Name: Fibrillin 1
Abbreviation: FBN1
Locus: Chromosome 3
Protein Length: 2872 aa
Gene Accession Number: NP_114313.1
Protein Accession Number: NC_005102.2
               Identity: 95%
               E-value: 0.0

Gallus gallus (Chicken)
Name: Fibrillin 1
Abbreviation: FBN1
Locus: Chromosome 10
Protein Length: 2930 aa
Gene Accession Number: NC_006097.2
Protein Accession Number: XP_413815.2
               Identity:  84%
               E-Value: 0.0

Figure 1. Gene and protein of Pan troglodytes

Figure 2. Gene and protein of Canus lupis familiaris

Figure 3. Gene and protein of Bos taurus

Figure 4. Gene and Protein of Mus musculus

Figure 5. Gene and protein of Rattus norvegivcus

Figure 6. Gene and protein of Gallus gallus

Analysis

The following homologies were found using Homologene by searching the database for FBN1. To compare the homologs, a Blast search was conducted with the proteins because the DNA sequence was too long to process. While all Blast searches gave E-Values of zero, Pan troglodytes (Chimpanzee) had the highest max identity percentage of 99%. This result was expected as Chimpanzees are the closest human relative among the homologs measured. It is also important to note that Mus musculus was 96% max identity, also a very high value. The mouse model is used in many fibrillinopathy studies for this reason. All these homologies are put into a phylogeny tree, which can be seen on the Phylogeny page.

References

(1) Homologene http://www.ncbi.nlm.nih.gov/homologene

Gabrielle Waclawik
[email protected]
May 13, 2010
www.gen677.weebly.com