GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00001941
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
presence of enamel
Trait State in Taxon B
absence of enamel in teeth
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Latin Name
Common Name
dwarf sperm whale
Synonyms
Kogia simus; dwarf sperm whale; Kogia sima (Owen, 1866)
Rank
species
Lineage
Show more ... Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria; Cetartiodactyla; Cetacea; Odontoceti; Physeteridae; Kogia
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
pygmy sperm whale
Synonyms
pygmy sperm whale
Rank
species
Lineage
Show more ... Teleostomi; Euteleostomi; Sarcopterygii; Dipnotetrapodomorpha; Tetrapoda; Amniota; Mammalia; Theria; Eutheria; Boreoeutheria; Laurasiatheria; Cetartiodactyla; Cetacea; Odontoceti; Physeteridae; Kogia
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Presumptive Null
Yes
Molecular Type
Aberration Type
SNP
SNP Coding Change
Nonsense
Molecular Details of the Mutation
opal stop codon (TGA) in the propeptide-coding region of MMP20 exon 2 in a single individual of the pygmy sperm whale Kogia breviceps
Experimental Evidence
Taxon A Taxon B Position
Codon - TGA -
Amino-acid - STP -
Authors
Meredith RW; Gatesy J; Cheng J; Springer MS
Abstract
Whales in the suborder Mysticeti are filter feeders that use baleen to sift zooplankton and small fish from ocean waters. Adult mysticetes lack teeth, although tooth buds are present in foetal stages. Cladistic analyses suggest that functional teeth were lost in the common ancestor of crown-group Mysticeti. DNA sequences for the tooth-specific genes, ameloblastin (AMBN), enamelin (ENAM) and amelogenin (AMEL), have frameshift mutations and/or stop codons in this taxon, but none of these molecular cavities are shared by all extant mysticetes. Here, we provide the first evidence for pseudogenization of a tooth gene, enamelysin (MMP20), in the common ancestor of living baleen whales. Specifically, pseudogenization resulted from the insertion of a CHR-2 SINE retroposon in exon 2 of MMP20. Genomic and palaeontological data now provide congruent support for the loss of enamel-capped teeth on the common ancestral branch of crown-group mysticetes. The new data for MMP20 also document a polymorphic stop codon in exon 2 of the pygmy sperm whale (Kogia breviceps), which has enamel-less teeth. These results, in conjunction with the evidence for pseudogenization of MMP20 in Hoffmann's two-toed sloth (Choloepus hoffmanni), another enamel-less species, support the hypothesis that the only unique, non-overlapping function of the MMP20 gene is in enamel formation.
Additional References
RELATED GEPHE
Related Genes
Related Haplotypes
No matches found.
COMMENTS
@ParallelEvolution in baleen whales.
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