During development, human beta-globin locus regulation undergoes two critical switches, the embryonic-to-fetal and fetal-to-adult hemoglobin switches. To define the role of the fetal (A)gamma-globin promoter in switching, human beta-globin-YAC transgenic mice were produced with the (A)gamma-globin promoter replaced by the erythroid porphobilinogen deaminase (PBGD) promoter (PBGD(A)gamma-YAC). A...

A stringent test for imprint control elements is to examine their function at ectopic loci in transgenic experiments. Igf2 and H19 are part of a larger imprinting region and as a first step, we examined these reciprocally imprinted genes in transgenic experiments using a 130 kb YAC clone. After paternal inheritance, H19 was appropriately repressed and Igf2 was expressed, irrespective of copy nu...

Two mouse YACs, PA-2 and PA-3, contain the Xist gene and are 460 kb and 3.3 Mb long respectively. While PA-2 is non-chimeric, PA-3 contains a substantial proportion of non-contiguous DNA. As a prerequisite to functional studies of the role of this region in X inactivation, we have created a deletion series of YACs that are spaced at approximately 50 kb intervals and were able to eliminate the u...

We describe the mapping of 979 randomly selected large yeast artificial chromosome (YAC) clones of Drosophila DNA by in situ hybridization to polytene chromosomes. Eight hundred and fifty-five of the clones are euchromatic and have primary hybridization sites in the banded portions of the polytene chromosomes, whereas 124 are heterochromatic and label the chromocenter. The average euchromatic c...

Yeast artificial chromosome (YAC) clones were assigned on rice (Oryza saliva L. cv. Nipponbare) chromosomes 10 and 12 using DNA markers from our high-density linkage map. Out of 1,383 markers localized in this genetic map, 68 and 74 markers were located on chromosomes 10 and 12, respectively. Screening of the YAC genomic library was conducted by colony hybridization and Southern hybridization u...

The elements controlling the complex developmental and tissue-specific expression of the cystic fibrosis transmembrane conductance regulator (CFTR) gene lie outside the basal promoter region and have not been characterized. We previously identified a tissue-specific DNase I hypersensitive site (DHS) in intron 1 (185 + 10 kb) of the CFTR gene. Here we show that removal of the core element abolis...

BACKGROUND Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder, caused by a GAA repeat expansion mutation within intron 1 of the FXN gene. We have previously established and performed preliminary characterisation of several human FXN yeast artificial chromosome (YAC) transgenic FRDA mouse models containing GAA repeat expansions, Y47R (9 GAA repeats), YG8R (90 and 190 G...

We examined unequal homologous DNA recombination between human repetitive DNA elements located on a yeast artificial chromosome (YAC) and transforming plasmid molecules. A plasmid vector containing an Alu element, as well as a sequence identical to a unique site on a YAC, was introduced into yeast and double recombinant clones analyzed. Recombination occurs between vector and YAC Alu elements s...

The initiation of X-chromosome inactivation in female mammals is controlled by a key locus, the X-inactivation centre (Xic). The Xist gene, which maps to the candidate region for Xic and is expressed exclusively from the inactive X chromosome, is thought to be an essential component of the Xic. To test whether sequences spanning several hundred kilobases and including Xist from the Xic region a...