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Non-concerted ITS evolution in Mammillaria (Cactaceae).

Authors :
Harpke D
Peterson A
Source :
Molecular phylogenetics and evolution [Mol Phylogenet Evol] 2006 Dec; Vol. 41 (3), pp. 579-93. Date of Electronic Publication: 2006 Jun 06.
Publication Year :
2006

Abstract

Molecular studies of 21 species of the large Cactaceae genus Mammillaria representing a variety of intrageneric taxonomic levels revealed a high degree of intra-individual polymorphism of the internal transcribed spacer region (ITS1, 5.8S rDNA, ITS2). Only a few of these ITS copies belong to apparently functional genes, whereas most are probably non-functional (pseudogenes). As a multiple gene family, the ITS region is subjected to concerted evolution. However, the high degree of intra-individual polymorphism of up to 36% in ITS1 and up to 35% in ITS2 suggests a non-concerted evolution of these loci in Mammillaria. Conserved angiosperm motifs of ITS1 and ITS2 were compared between genomic and cDNA ITS clones of Mammillaria. Some of these motifs (e.g., ITS1 motif 1, 'TGGT' within ITS2) in combination with the determination of GC-content, length comparisons of the spacers and ITS2 secondary structure (helices II and III) are helpful in the identification of pseudogene rDNA regions.

Details

Language :
English
ISSN :
1055-7903
Volume :
41
Issue :
3
Database :
MEDLINE
Journal :
Molecular phylogenetics and evolution
Publication Type :
Academic Journal
Accession number :
16843685
Full Text :
https://doi.org/10.1016/j.ympev.2006.05.036