799 research outputs found
Recommended from our members
Comparison of Octopus dofleini hemocyanin paralogues and evidence for recent divergence
Presented here is an in depth comparison of the Octopus dofleini hemocyanin paralogues, designated A and G. The protein sequences coded by these genes are each comprised of seven oxygen-binding units, or functional units (FU-a to FU-g). Each FU is approximately 400 amino acids in length and a linker region separates each of them. Within every linker, a phase one intron (found between the first and second base of an amino acid codon) was found which varies from 100-910 base pairs in length. Three FUs are split by internal introns, dividing FU-b, FU-e, and FU-f into two exons. These internal introns show no phase pattern like the linker introns and appear to represent later insertion events. The intron within FU-e houses a microsatellite region that contains di- and tetra- nucleotide tandem repeats. Variation between the two Octopus paralogues is greatest in this microsatellite region, however the similarity is still striking. Given the higher rate of mutation for microsatellites, due mainly to slippage, this similarity either lends support to the recent divergence of these two
paralogues or implies some kind of secondary-structure related function that has slowed the divergence of these microsatellites. The high degree of similarity in the coding regions, as well as the non-coding regions, of this gene is evidence that suggests these paralogues have recently diverged. Comparisons between the two Octopus sequences and comparisons to related hemocyanins will help uncover the evolutionary origins of this gene
- …