Wolbachia genome integrated in an insect chromosome: evolution and fate of laterally transferred endosymbiont genes.

Recent accumulation of microbial genome data has demonstrated that lateral gene transfers constitute an important and universal evolutionary process in prokaryotes, while those in multicellular eukaryotes are still regarded as unusual, except for endosymbiotic gene transfers from mitochondria and plastids. Here we thoroughly investigated the bacterial genes derived from a Wolbachia endosymbiont on the nuclear genome of the beetle Callosobruchus chinensis. Exhaustive PCR detection and Southern blot analysis suggested that approximately 30% of Wolbachia genes, in terms of the gene repertoire of wMel, are present on the insect nuclear genome.

AT-rich sequences containing Arabidopsis-type telomere sequence and their chromosomal distribution in Pinus densiflora.

Japanese red pine Pinus densiflora has 2 n=24 chromosomes and after FISH-detection of Arabidopsis-type (A-type) telomere sequences, many telomere signals were observed on these chromosomes at interstitial and proximal regions in addition to the chromosome ends. These interstitial and proximal signal sites were observed as DAPI-positive bands, suggesting that the interstitial and proximal telomere signal sites are composed of AT-rich highly repetitive sequences. Four DNA clones (PAL810, PAL1114, PAL1539, PAL1742) localized at the interstitial telomere signals were selected from AluI-digested genomic DNA library using colony blot hybridization probed with A-type telomere sequences and characterized using FISH and Southern blot hybridization.

Organization of the KpnI family of chromosomal distal-end satellite DNAs in Silene latifolia.

The major satellite DNAs of the dioecious plant Silene latifolia are represented by the repetitive sequences X43.1, RMY1 and members of the SacI family, which are located at the distal ends of chromosomes. To characterize the satellite DNAs at the distal ends of the chromosomes in S.

Evolution of 5S rDNA units and their chromosomal localization in Allium cepa and Allium schoenoprasum revealed by microdissection and FISH.

Allium cepa and Allium schoenoprasum each possess 5S rDNA units of two different sizes. The evolution of the two repeat units and their chromosomal localization were investigated. A.

Distribution of interstitial telomere-like repeats and their adjacent sequences in a dioecious plant, Silene latifolia.

The dioecious plant Silene latifolia has large, heteromorphic X and Y sex chromosomes that are thought to be derived from rearrangements of autosomes. To reveal the origin of the sex chromosomes in S. latifolia, we isolated and characterized telomere-homologous sequences from intra-chromosomal regions (interstitial telomere-like repeats; ITRs) and ITR-adjacent sequences (IASs).

The identification and analysis of the sequences that allow the detection of Allium cepa chromosomes by GISH in the allodiploid A. wakegi.

In Allium wakegi, which is an allodiploid species between Allium cepa and Allium fistulosum, each genome can be clearly distinguished using genomic in situ hybridization (GISH). Genomic DNA of A. cepa and A.

Tandem repeat DNA localizing on the proximal DAPI bands of chromosomes in Larix, Pinaceae.

Repetitive DNA was cloned from HindIII-digested genomic DNA of Larix leptolepis. The repetitive DNA was about 170 bp long, had an AT content of 67%, and was organized tandemly in the genome. Using fluorescence in situ hybridization and subsequent DAPI banding, the repetitive DNA was localized in DAPI bands at the proximal region of one arm of chromosomes in L.