The researchers looked deeper into these observations, in hopes of gaining insight into the mechanisms underlying the high evolutionary rate and extraordinary immunologic plasticity of influenza HA. They probed in more detail the precise codons that are used by the virus to encode the influenza HA1 protein. The discriminated between codons on the basis of volatility. Each three-nucleotide codon is related by a single nucleotide change to nine 'mutational neighbours.' Of those nine mutations, some proportion change the codon to a synonymous codon and some change it to a nonsynonymous one, which directs the incorporation of a different amino acid into the protein. More volatile codons are those for which a larger proportion of those nine mutational neighbours encode an amino acid change. The use of particular codons in a gene at a frequency that is disproportionate to their random selection for encoding a chosen amino acid is termed codon bias. Such bias is common and is influenced by many factors, but here the collaborators found strong evidence for codon bias that was particular for and restricted to the amino acids making up the HA1 epitopes. Remarkably, they observed that influenza employs a disproportionate number of volatile codons in its epitope-coding sequences. There was a bias for the use of codons that had the fewest synonymous mutational neighbours. In other words, influenza HA1 appears to have optimized the speed with which it can change amino acids in its epitopes. Amino acid changes can arise from fewer mutational events. The antibody combining regions are optimized to use codons that have a greater likelihood to undergo nonsynonymous single nucleotide substitutions : they are optimized for rapid evolution. Michael G Cordingley
Folks, it's time to evolve. That's why we're troubled. You know why our institutions are failing us, the church, the state, everything's failing? It's because, um — they're no longer relevant. We're supposed to keep evolving. Evolution did not end with us growing opposable thumbs....
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Bill Hicks
Do you see the slightest evidence anywhere in the universe that creation came to an end with the birth of man? Do you see the slightest evidence anywhere out there that man was the climax toward which creation had been straining from the beginning?. .Very...
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Daniel Quinn
The fossil record implies trial and error, the inability to anticipate the future, features inconsistent with a Great Designer (though not a Designer of a more remote and indirect temperament.)
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Carl Sagan
A hydrogen atom in a cell at the end of my nose was once part of an elephant's trunk. A carbon atom in my cardiac muscle was once in the tail of a dinosaur.
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Jostein Gaarder
The researchers looked deeper into these observations, in hopes of gaining insight into the mechanisms underlying the high evolutionary rate and extraordinary immunologic plasticity of influenza HA. They probed in more detail the precise codons that are used by the virus to encode the influenza...
