|Publication Type:||Journal Article|
|Year of Publication:||2003|
|Authors:||Y. Terai, Takahashi, K. , Nishida, M. , Sato, T. , Okada, N.|
|Journal:||Molecular Biology and Evolution|
|Keywords:||African mouthbrooders, Article Geographic Terms: Africa,, Article Subject Terms: Allelles, Article Taxonomic Terms:, cichlidae, Cladistics, Evolution, fish, Freshwater, G 07260 Taxonomy, systematics and evolutionary genetics, G 07371 Fish, Genetics and evolution, Great Lakes, Lakes, Molecular biology, Mutations, Nucleotide sequence, phylogeny, population genetics, Portugal, Setubal, Sines, Q1 01345, speciation, Steatocranus, tilapia, transposon SINE|
Cichlid fishes of the east African Great Lakes represent a paradigm of adaptive radiation. We conducted a phylogenetic analysis of cichlids including pan-African and West African species by using insertion patterns of short interspersed elements (SINEs) at orthologous loci. The monophyly of the east African cichlids was consistently supported by seven independent insertions of SINE sequences that are uniquely shared by these species. In addition, data from four other loci indicated that the genera Tilapia (pan-African) and Steatocranus (west African) are the closest relatives to east African cichlids. However, relationships among Tilapia, Steatocranus, and the east African clade were ambiguous because of incongruencies among topologies suggested by insertion patterns of SINEs at six other loci. One plausible explanation for this phenomenon is incomplete lineage sorting of alleles containing or missing a SINE insertion at these loci during ancestral speciation. Such incomplete sorting may have taken place earlier than 14 MYA, followed by random and stochastic fixation of the alleles in subsequent lineages. These observations prompted us to consider the possibility that cichlid speciation occurred at an accelerated rate during this period when the African Great Lakes did not exist. The SINE method could be useful for detecting ancient exclusive speciation events that tend to remain hidden during conventional sequence analyses because of accumulated point mutations.
|Alternate Journal:||Mol. Biol. Evol.|
Using SINEs to Probe Ancient Explosive Speciation: "Hidden" Radiation of African Cichlids?
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