Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana.
Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2.
Lin
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Institute for Genomic Research, Rockville, Maryland 20850, USA.
Kaul
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Rounsley
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Shea
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Benito
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Town
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Fujii
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Bowman
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Barnstead
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Feldblyum
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Ketchum
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Ronning
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Salzberg
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D017360:Arabidopsis / Q000235:genetics*; D002467:Cell Nucleus / Q000235:genetics; D002503:Centromere; D002874:Chromosome Mapping; D018744:DNA, Plant; D019143:Evolution, Molecular; D020440:Gene Duplication; D017343:Genes, Plant / Q000502:physiology; D008928:Mitochondria / Q000235:genetics; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology; D017422:Sequence Analysis, DNA
D018744:DNA, Plant; D010940:Plant Proteins