in several inner segments of influenza A we typically only see limited (~10)
amino-acid changes in wild avian flu so that these segments are close to the calculated
"index"-protein-sequence here:
Synonymous changes are not affected and do occur at normal rates.
No such restriction is observed in mammalean flu,
which accumulates ~2.5*10^-3 nucleotide changes
and ~4*10^-4 amino-acid changes per position per year.
(6 nucleotide changes and 0.8 amino-acid changes in PB2 per year in humans)
Poultry and swine are in the middle between mallards and humans
wrt. protein-sequence-diversity = distance to the index :
mallards-wild birds-poultry-swine-humans
These index-like protein sequences occur independently
on different genetical backgrounds. So do the exactly same
(or more often: almost identical) protein sequences appears in
North-American and Eurasian lineages where usually we do see
separate evolution.
But while the protein sequences are similar, there are many synonymous
nucleotide differences, signalling a distant common ancestor.
So, A/blue winged teal/Ohio/926/2002(H3N8)
and A/mallard/Netherlands/2/2005(H4N2) have
0 amino-acid differences (identical to the PB2-index)
but have 343 nucleotide differences. There are other such examples and some
viruses only have 0-3 differences to the index in all inner segments.
This phenomenon can be visualized by plotting protein-differences
vs. nucleotide-differences of pairs of avian flu segments:
The "clouds" approach the y-axis high above zero.
The same picture for humans shows proportional acquisition of protein-
and nucleotide-difference:
discussion here: http://www.flutrackers.com/forum/sho...d.php?t=135212
or start a new thread
----------------------------------
keywords:
bird index , bird flu index , wild bird index , wild bird flu index , birdflu protein sequences index
mallard index , mallard flu index , mallardflu index , avian influenza reference protein strain
avian influenza reference index , gsgs , influenza , avian influenza , mallard influenza ,
influenza in wild birds , poultry , mammals , hemagglutinin , neuraminidase , mutations ,
mutation frequency , amino acid mutations , aminoacid mutations , protein mutations ,
evolution , mutation rate , protein mutation rate
amino-acid changes in wild avian flu so that these segments are close to the calculated
"index"-protein-sequence here:
Synonymous changes are not affected and do occur at normal rates.
No such restriction is observed in mammalean flu,
which accumulates ~2.5*10^-3 nucleotide changes
and ~4*10^-4 amino-acid changes per position per year.
(6 nucleotide changes and 0.8 amino-acid changes in PB2 per year in humans)
Poultry and swine are in the middle between mallards and humans
wrt. protein-sequence-diversity = distance to the index :
mallards-wild birds-poultry-swine-humans
These index-like protein sequences occur independently
on different genetical backgrounds. So do the exactly same
(or more often: almost identical) protein sequences appears in
North-American and Eurasian lineages where usually we do see
separate evolution.
But while the protein sequences are similar, there are many synonymous
nucleotide differences, signalling a distant common ancestor.
So, A/blue winged teal/Ohio/926/2002(H3N8)
and A/mallard/Netherlands/2/2005(H4N2) have
0 amino-acid differences (identical to the PB2-index)
but have 343 nucleotide differences. There are other such examples and some
viruses only have 0-3 differences to the index in all inner segments.
This phenomenon can be visualized by plotting protein-differences
vs. nucleotide-differences of pairs of avian flu segments:
The "clouds" approach the y-axis high above zero.
The same picture for humans shows proportional acquisition of protein-
and nucleotide-difference:
discussion here: http://www.flutrackers.com/forum/sho...d.php?t=135212
or start a new thread
----------------------------------
keywords:
bird index , bird flu index , wild bird index , wild bird flu index , birdflu protein sequences index
mallard index , mallard flu index , mallardflu index , avian influenza reference protein strain
avian influenza reference index , gsgs , influenza , avian influenza , mallard influenza ,
influenza in wild birds , poultry , mammals , hemagglutinin , neuraminidase , mutations ,
mutation frequency , amino acid mutations , aminoacid mutations , protein mutations ,
evolution , mutation rate , protein mutation rate
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