RRC ID 29674
著者 Maruyama S, Misumi O, Ishii Y, Asakawa S, Shimizu A, Sasaki T, Matsuzaki M, Shin-i T, Nozaki H, Kohara Y, Shimizu N, Kuroiwa T.
タイトル The minimal eukaryotic ribosomal DNA units in the primitive red alga Cyanidioschyzon merolae.
ジャーナル DNA Res
Abstract Cyanidioschyzon merolae is a small unicellular red alga that is considered to belong to one of the most deeply branched taxa in the plant kingdom. Its genome size is estimated to be 16.5 Mbp, one of the smallest among free-living eukaryotes. In the nucleus containing this small genome, one nucleolus is clearly observed, but the molecular basis for the intranuclear structure including ribosomal DNA organization is still unclear. We constructed a bacterial artificial chromosome library for C. merolae 10D composed of two subsets with different insert size distributions. The two subsets have average insert sizes of 97 and 48 kb, representing 10.0- and 6.9-fold genome-equivalent coverage of the haploid genome, respectively. For application to whole-genome shotgun sequencing, the termini of each clone were sequenced as sequence-tagged connectors and mapped on the contigs assigned to chromosomes. Screening for rRNA genes by conventional colony hybridization with high-density filter blots and subsequent sequencing revealed that the C. merolae genome contained the smallest number of ribosomal DNA units among all the eukaryotes examined to date. They consist of only 3 single units of rRNA genes distributed on separate chromosomal loci, representing an implication for concerted evolution. Based on these results, the origin and evolution of the nucleolus are discussed.
巻・号 11(2)
ページ 83-91
公開日 2004-4-30
DOI 10.1093/dnares/11.2.83
PMID 15449541
MeSH Base Sequence Cell Nucleolus / genetics* Cell Nucleolus / ultrastructure Chromosome Mapping* Chromosomes, Artificial, Bacterial DNA Primers DNA, Ribosomal / genetics* Evolution, Molecular* Gene Components Gene Library Microscopy, Electron Microscopy, Fluorescence Molecular Sequence Data Rhodophyta / genetics* Sequence Analysis, DNA
IF 4.009
引用数 18
WOS 分野 GENETICS & HEREDITY
リソース情報
藻類 NIES-3377