GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00000455
Main curator
Martin
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Homo sapiens
Trait State in Taxon B
Crocodyilus niloticus
Ancestral State
Data not curated
Taxonomic Status
Taxon A
Latin Name
Common Name
human
Synonyms
human; man; Homo sapiens Linnaeus, 1758; Home sapiens; Homo sampiens; Homo sapeins; Homo sapian; Homo sapians; Homo sapien; Homo sapience; Homo sapiense; Homo sapients; Homo sapines; Homo spaiens; Homo spiens; Humo sapiens
Rank
species
Lineage
Show more ... opterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Euarchontoglires; Primates; Haplorrhini; Simiiformes; Catarrhini; Hominoidea; Hominidae; Homininae; Homo
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
Nile crocodile
Synonyms
Nile crocodile; African crocodile; Crocodylus niloticus Laurenti, 1768
Rank
species
Lineage
Show more ... ta; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Sauropsida; Sauria; Archelosauria; Archosauria; Crocodylia; Longirostres; Crocodylidae; Crocodylus
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Presumptive Null
No
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsynonymous
Molecular Details of the Mutation
No more than 12 amino acid substitutions required for providing crocodile-like properties in engineered human Hb - effect of single amino acid changes not tested
Experimental Evidence
Taxon A Taxon B Position
Codon - - -
Amino-acid - - -
Authors
Komiyama NH; Miyazaki G; Tame J; Nagai K
Abstract
Crocodiles are able to remain under water for more than one hour without surfacing to breathe and often kill their prey by drowning it. How do crocodiles stay under water for a long time? When they hold their breath, bicarbonate ions, the final product of respiration, accumulate and drastically reduce the oxygen affinity of haemoglobin, releasing a large fraction of haemoglobin-bound oxygen into the tissues. We have now located the bicarbonate-ion-binding site at the alpha 1 beta 2-subunit interface by making various human-crocodile chimaeric haemoglobins. Furthermore, we have been able to transplant the bicarbonate effect into human haemoglobin by replacing only a few residues, even though the amino-acid sequence identity between crocodile (Crocodylus niloticus) and human haemoglobins is only 68% for the alpha- and 51% for the beta-subunit. These results indicate that an entirely new function which enables species to adapt to a new environment could evolve in a protein by a relatively small number of amino-acid substitutions in key positions.
Additional References
RELATED GEPHE
Related Haplotypes
No matches found.
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