| Affiliation: | (1) Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK;(2) Vogelwarte Hiddensee, Universitat Greifswald, D-18565 Kloster/Hiddensee, Germany |
| Abstract: | The origin and evolution of a 128-bp tandem repeat in the mtDNA control region of shrikes (Lanius: Aves) were investigated. The tandem repeat is present in only two species, L. excubitor and L. ludovicianus. In contrast to the variation in repeat number in L. ludovicianus, all individuals of three subspecies of L. excubitor had three repeats. Comparative analysis suggests that a short direct repeat, and a secondary structure including the tandem repeat and a downstream inverted repeat, may be important in the origin of the tandem repeat by slipped-strand mispairing and its subsequent turnover. Homogenization of repeat sequences is most simply explained by expansion and contraction of the repeat array. Surprisingly, mtDNA sequences from L. excubitor were found to be paraphyletic with respect to L. ludovicianus. These results show the utility of a comparative analysis for insights into the evolutionary dynamics of mtDNA tandem repeats.[Reviewing Editor: Martin Kreitman] |
