Dataset Information

DNA variation in the basic chitinase locus (ChiB) region of the wild plant Arabidopsis thaliana.

ABSTRACT: Nucleotide variation in a 2.2-kbp region of basic chitinase (ChiB) locus in 17 ecotypes of Arabidopsis thaliana was compared with previously investigated regions to investigate genetic mechanisms acting on DNA polymorphism. In the ChiB region, dimorphic DNA variation was detected, as in the Adh and ChiA regions. Nucleotide diversity (pi) of the entire region was 0.0091, which was similar to those of the two other regions. About half of polymorphic sites (37/87) in the ChiB region were observed in only two ecotypes. Tajima's D was negative but not significantly, while Fu and Li's D* was positive. Neither McDonald-Kreitman nor Hudson, Kreitman, Aguadé tests showed a significant result, indicating that these loci were under similar evolutionary mechanisms before and after speciation. Linkage disequilibria were observed within the three regions because of dimorphic polymorphisms. Interlocus linkage disequilibrium was not detected between the Adh and the two chitinase regions, but was observed between the ChiA and ChiB regions. This could be due to epistatic interaction between the two chitinase loci, which are located on different chromosomes.

SUBMITTER: Kawabe A

PROVIDER: S-EPMC1460836 | biostudies-other | 1999 Nov

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

DNA variation in the basic chitinase locus (ChiB) region of the wild plant Arabidopsis thaliana.

Kawabe A A Miyashita N T NT

Genetics 19991101 3

Nucleotide variation in a 2.2-kbp region of basic chitinase (ChiB) locus in 17 ecotypes of Arabidopsis thaliana was compared with previously investigated regions to investigate genetic mechanisms acting on DNA polymorphism. In the ChiB region, dimorphic DNA variation was detected, as in the Adh and ChiA regions. Nucleotide diversity (pi) of the entire region was 0.0091, which was similar to those of the two other regions. About half of polymorphic sites (37/87) in the ChiB region were observed i ...[more]

PMID: 10545472

Similar Datasets

Project description:BACKGROUND: DNA methylation is an important biochemical mark that silences repetitive sequences, such as transposons, and reinforces epigenetic gene expression states. An important class of repetitive genes under epigenetic control in eukaryotic genomes encodes ribosomal RNA (rRNA) transcripts. The ribosomal genes coding for the 45S rRNA precursor of the three largest eukaryotic ribosomal RNAs (18S, 5.8S, and 25-28S) are found in nucleolus organizer regions (NORs), comprised of hundreds to thousands of repeats, only some of which are expressed in any given cell. An epigenetic switch, mediated by DNA methylation and histone modification, turns rRNA genes on and off. However, little is known about the mechanisms that specify and maintain the patterns of NOR DNA methylation. RESULTS: Here, we explored the extent of naturally-occurring variation in NOR DNA methylation among accessions of the flowering plant Arabidopsis thaliana. DNA methylation in coding regions of rRNA genes was positively correlated with copy number of 45S rRNA gene and DNA methylation in the intergenic spacer regions. We investigated the inheritance of NOR DNA methylation patterns in natural accessions with hypomethylated NORs in inter-strain crosses and defined three different categories of inheritance in F1 hybrids. In addition, subsequent analysis of F2 segregation for NOR DNA methylation patterns uncovered different patterns of inheritance. We also revealed that NOR DNA methylation in the Arabidopsis accession Bor-4 is influenced by the vim1-1 (variant in methylation 1-1) mutation, but the primary effect is specified by the NORs themselves. CONCLUSION: Our results indicate that the NORs themselves are the most significant determinants of natural variation in NOR DNA methylation. However, the inheritance of NOR DNA methylation suggests the operation of a diverse set of mechanisms, including inheritance of parental methylation patterns, reconfiguration of parental NOR DNA methylation, and the involvement of trans-acting modifiers.

Dataset Information

DNA variation in the basic chitinase locus (ChiB) region of the wild plant Arabidopsis thaliana.

Publications

DNA variation in the basic chitinase locus (ChiB) region of the wild plant Arabidopsis thaliana.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets