Distribution of (CGG)n and FMR-1 associated microsatellite alleles in a normal Chilean population.

We report on the allele distribution in a normal Chilean population at 2 microsatellite loci neighbouring the FRAXA locus and at the CGG repeat in the 5' end of the FMR-1 gene, which causes the fragile X syndrome. The most common CGG repeat allele was 30 (41.7%), with 29 being second most common (30.

Purification of Escherichia coli chromosomal segments without cloning.

Pairs of genomic insertions made with elements carrying any one of several frequently used rare restriction sites allow physical purification of insertion delimited genes. However, native rare restriction sites can, either by causing (i) fragmentation of targeted intervals or (ii) generation of additional fragments that overlap electrophoretically with targeted ones, place severe limitations on this approach. We present a series of Escherichia coli mini-Tn10 insertions containing the rare-cutting polylinker 2 (RCP2) of rare restriction sites, which includes the 18-base-pair I-SceI site (absent from native E.

New tools for integrated genetic and physical analyses of the Escherichia coli chromosome.

Genetic and biophysical techniques have traditionally been applied to genome mapping independently of one another. We present a series of Escherichia coli mini-Tn10 insertions that contain the rare-cutting polylinker 1 (RCP1) of rare restriction sites [including BlnI/AvrII, SpeI, NheI, XbaI, NotI, PacI and SfiI; Mahillon and Kleckner, Gene 116 (1992) 69-74] which allows them to be used not just for genetic mapping, but also for rapid physical mapping and integrated physical and genetic mapping of the E. coli chromosome.