This web page was created as an assignment for Genetics 677, an undergraduate course at UW-Madison.
Phylogram of LMNA gene
Above is the phylogeny of homologs of lamin coding genes in a variety of species. This was retrieved using TreeFam. This tree shows the broad scope of this gene in nature and the fact that it encodes necessary protein function for cell survival, which would make it fairly well conserved. Note that there are several. All of these have genes code for similar functions, filaments necessary in the nucleus, and therefore have similarities in sequences. Those in the lmna branching of this tree show the greatest seqeunce similarity and also function. Interestingly, since the LMNA gene codes for such vital functions and is highly conserved, it is not surprising to see rather small mutations in the gene (i.e. single base substitution) causing devastating disorders like HGPS and Emery-Dreifuss muscular dystrophy (1).
Above is a cladogram of LMNA homologs in humans (Homo), chimpanzees (Pan), dogs (Canis), cows (Bos), zebrafish (Danio), and mice (Mus). Seen in the cladogram, chimpanzees have the most similar homolog, whereas the zebrafish is the most dissimilar. It would be expected through evolution to see all of the mammals to have very similar homolog, especially since the gene encodes important lamins for nuclear envelope structural integrity, with the fish being the most unrelated.
References
1. Hutchinson, C J. (2002). Lamins: building blocks or regulators of gene expression?. Nature, (3), 848-858. doi: 10.1038/nrm950.
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