Origin and evolution of homologous repeated sequences in the mitochondrial DNA control region of shrews.

Détails

ID Serval
serval:BIB_C0B65ED6084A
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Origin and evolution of homologous repeated sequences in the mitochondrial DNA control region of shrews.
Périodique
Molecular Biology and Evolution
Auteur(s)
Fumagalli L., Taberlet P., Favre L., Hausser J.
ISSN
0737-4038[print], 0737-4038[linking]
Statut éditorial
Publié
Date de publication
1996
Volume
13
Numéro
1
Pages
31-46
Langue
anglais
Résumé
The complete mitochondrial DNA (mtDNA) control region was amplified and directly sequenced in two species of shrew, Crocidura russula and Sorex araneus (Insectivora, Mammalia). The general organization is similar to that found in other mammals: a central conserved region surrounded by two more variable domains. However, we have found in shrews the simultaneous presence of arrays of tandem repeats in potential locations where repeats tend to occur separately in other mammalian species. These locations correspond to regions which are associated with a possible interruption of the replication processes, either at the end of the three-stranded D-loop structure or toward the end of the heavy-strand replication. In the left domain the repeated sequences (R1 repeats) are 78 bp long, whereas in the right domain the repeats are 12 bp long in C. russula and 14 bp long in S. araneus (R2 repeats). Variation in the copy number of these repeated sequences results in mtDNA control region length differences. Southern blot analysis indicates that level of heteroplasmy (more than one mtDNA form within an individual) differs between species. A comparative study of the R2 repeats in 12 additional species representing three shrew subfamilies provides useful indications for the understanding of the origin and the evolution of these homologous tandemly repeated sequences. An asymmetry in the distribution of variants within the arrays, as well as the constant occurrence of shorter repeated sequences flanking only one side of the R2 arrays, could be related to asymmetry in the replication of each strand of the mtDNA molecule. The pattern of sequence and length variation within and between species, together with the capability of the arrays to form stable secondary structures, suggests that the dominant mechanism involved in the evolution of these arrays in unidirectional replication slippage.
Mots-clé
Animals, Base Sequence, DNA, Mitochondrial/genetics, Evolution, Molecular, Molecular Sequence Data, Nucleic Acid Conformation, Repetitive Sequences, Nucleic Acid, Sequence Alignment, Sequence Homology, Nucleic Acid, Shrews/genetics
Pubmed
Web of science
Création de la notice
24/01/2008 19:09
Dernière modification de la notice
20/08/2019 15:35
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