On the pBuM189 satellite DNA variability among South American populations of Drosophila buzzatii.
The pBuM189 satellite DNA was analysed in Drosophila buzzatii populations that cover most of the species distribution in South America. This satDNA consists of A + T-rich monomers of 189 bp and previous studies showed a fast rate of evolutionary change of this component of D. buzzatii genome. A total of 63 pBuM189 repetition units from 14 D. buzzatii populations (9 from Brazil and 5 from Argentina) were studied. The average nucleotide variability among the 63 repeats is 4.2 %. At least one repeat (Juan/4) seems to be part of another pBuM189 satDNA subfamily. The nucleotide alignment of all 63 repeats revealed no specific nucleotide substitutions, or indels, that could discriminate each population or groups of geographically close populations. Such lack of satDNA interpopulational differentiation is congruent with previous mtDNA data that indicate a high gene flow and very little population differentiation throughout most of the D. buzzatii distribution in South America. Gene flow might have been possible during glaciation events in the Pleistocene, such as the one occurred between 13,000 and 18,000 years ago, when D. buzzatii probably had a more continuous distribution than what is observed today.
Kuhn
Gustavo C S
GC
Faculdade de Medicina de Ribeirão Preto, Departamento de Genética, Universidade de São Paulo, Ribeirão Preto, Brazil.
Franco
Fernando F
FF
Silva
Wilson A
WA
Martinez-Rossi
Nilce M
NM
Sene
Fabio M
FM
D000818:Animals; D001483:Base Sequence; D004276:DNA, Satellite / Q000235:genetics*; D004330:Drosophila / Q000235:genetics*; D014644:Genetic Variation; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D004276:DNA, Satellite