Publications (5)11.4 Total impact
- [Show abstract] [Hide abstract] ABSTRACT: Sequence-tagged sites (STSs) were developed for three loci of uncertain X chromosomal localization (DXS122, DXS137, and DXS174) and were used to seed YAC contigs. Two contigs now total about 3.3 Mb formatted with 34 STSs. One contains DXS122 and DXS174 within 250 kb on single YACs; it is placed in Xq21.3-q22.1 by FISH analysis, which is consistent with somatic cell hybrid panel analyses and with the inclusion of a probe that detects polymorphism at the DXS118 locus already assigned to that general region. The other contig, which contains DXS137, is in Xq22.2 by FISH, consistent with cell hybrid analyses and with the finding that it covers the human COL4A5 and COL4A6 genes known to be in that vicinity. In addition to extending the cloned coverage of this portion of the X chromosome, these materials should aid, for example, in the further analysis of Alport syndrome.
- [Show abstract] [Hide abstract] ABSTRACT: Four collections of human X-specific YACs, derived from human cells containing supernumerary X chromosomes or from somatic cell hybrids containing only X human DNA were characterized. In each collection, 80 – 85% of YAC strains contained a single X YAC. Five thousand YACs from the various libraries were sized, and cocloning was assessed in subsets by the fraction of YAC insert-ends with non-X sequences. Cocloning was substantial, ranging up to 50% for different collections; and in agreement with previous indications, in all libraries the larger the YACs, the higher the level of cocloning. In libraries made from human — hamster hybrid cells, expected numbers of clones were recovered by STS-based screening; but unexpectedly, the two collections from cells with 4 or 5 X chromosomes yielded numbers of YACs corresponding to an apparent content of only about two X equivalents. Thus it is possible that the DNA of inactive X chromosomes is poorly cloned into YACs, speculatively perhaps because of its specialized chromatin structure.
Article: GENETIC MAPS OF CHROMOSOME-X