Length polymorphism and allele structure of trinucleotide microsatellites in natural accessions of Arabidopsis thaliana |
| |
Authors: | K Loridon B Cournoyer C Goubely A Depeiges G Picard |
| |
Institution: | (1) Laboratoire Biomove, UMR-CNRS 6547, Université Blaise Pascal Clermont-Ferrand II, 24, avenue des Landais, F-63177 Aubière Cedex, France E-mail: depeiges@cicsun.univ-bpclermont.fr, FR;(2) Laboratoire d’Ecologie Microbienne du Sol, UMR-CNRS 5557, Université Claude Bernard Lyon I, F-69622 Villeurbanne Cedex, France, FR |
| |
Abstract: | The objective of this work was to assess the degree of trinucleotide microsatellite length polymorphism in the selfing species
Arabidopsis thaliana. PCR amplifications of 12 microsatellite loci among 49 natural populations revealed between one to eight length variants
(alleles) for each locus. The average number of alleles per locus was four and the average genetic diversity index was 0.43.
Divergence between length variants was investigated at the nucleotide level. Several observations emerge from the sequence
data: (1) for most loci, length polymorphism results only from variations in the number of trinucleotide repeats; (2) for
a few others, some variability was noted in the flanking sequences; (3) for compound and interrupted loci containing two arrays
of trinucleotide repeats, length variations preferentially affect the longest one. Five of the Arabidopsis thaliana accessions were clearly composed of two sublines. In 2 other accessions, some heterozygous individual plants, probably resulting
from recent outcrosses, were found. A phylogenetic tree constructed on the basis of trinucleotide microsatellite allelic diversity
shows that genetic relationships among the accessions are not correlated with their geographic origin.
Received: 4 November 1997 / Accepted: 3 March 1998 |
| |
Keywords: | Microsatellite Trinucleotide repeats Simple sequence length polymorphism Arabidopsis thaliana Genetic diversity |
本文献已被 SpringerLink 等数据库收录! |
|