Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) acquire new spacers to generate adaptive immunity in prokaryotes. During spacer integration, the leader-preceded repeat is always accurately duplicated, leading to speculations of a repeat-length ruler. Here in Haloarcula hispanica, we demonstrate that the accurate duplication of its 30-bp repeat requires two conserved mid-repe...

Previous studies have suggested that some patients with large-scale mitochondrial DNA (mtDNA) deletions also presented a heteroplasmic 260 bp tandem duplication in the mtDNA D-loop region. Such duplications were observed not only in patients with mitochondrial pathology but also in aged subjects. However, the percentage of duplicated mtDNA did not exceed a few per cent of the total mtDNA, excep...

An insertion sequence (IS), designated ISApl1, was identified in Actinobacillus pleuropneumoniae. It was 1072 bp in length, and contained a large open reading frame (ORF), which encoded a putative transposase whose sequence was similar to that of transposases of various IS elements of the IS30 family. Another small ORF, a putative antisense repressor of transposase, was located in the opposite ...

The insertion sequence ISRm8 was identified by sequence analysis of the cryptic plasmid pRmeGR4b of Sinorhizobium meliloti GR4. ISRm8 is 1451 bp in length and carries 22/24-bp terminal imperfect inverted repeats with seven mismatches and a direct target site duplication of 3 bp. ISRm8 carries a unique open reading frame whose putative protein showed significant similarity to the insertion seque...

Duplications are often attributed to "unequal recombination" between separated, directly repeated sequence elements (>100 bp), events that leave a recombinant element at the duplication junction. However, in the bacterial chromosome, duplications form at high rates (10(-3)-10(-5)/cell/division) even without recombination (RecA). Here we describe 1800 spontaneous lac duplications trapped nonsele...

purpose: to report a case who had optic disc duplication, a rare congenital disorder characterized by two well-defined discs in one eye. case report: a 19 months-old child presented with unilateral epiphora in the right eye since birthday. the right eye was smaller than the left eye and mild ptosis was apparent. nasolacrimal duct probing was performed under general anesthesia. the examination r...

PURPOSE A recurrent 17 bp duplication (c.657ins17bp) of a segment of the paired-like homeodomain transcription factor 3 (PITX3) gene on human chromosome 10 has been reported in seven families with autosomal dominant posterior polar cataracts with or without anterior segment mesenchymal dysgenesis (ASMD). ASMD can include Peters anomaly with corneal clouding, iridolenticular corneal adhesions, d...

A new insertion sequence (IS element), IS1411, was identified downstream of the phenol degradation genes pheBA that originated from plasmid DNA of Pseudomonas sp. strain EST1001. According to sequence analysis, IS1411 belongs to a new family of IS elements that has recently been named the ISL3 family (J. Mahillon and M. Chandler, Microbiol. Mol. Biol. Rev. 62:725-774, 1998). IS1411 generates 8-...

Synpolydactyly (SPD) is a limb malformation that shows a characteristic manifestation in both hands and feet. This condition is inherited as an autosomal dominant trait with reduced penetrance. We have recently mapped this locus centromeric to the HOXD8 intragenic marker and suggested the HOXD13 gene as a potential candidate for this condition. The genomic structure of HOXD13 established in thi...