Towards the finer mapping of facioscapulohumeral muscular dystrophy at 4q35: construction of a laser microdissection library.
Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal-dominant disorder which has been mapped to the 4q35 region. In order to saturate this distal 4q region with DNA markers, a laser-based chromosomal microdissection and microcloning procedure was used to construct a genomic library from the distal 20% of chromosome 4, derived from a single human metaphase spread. Of the 100 microclones analyzed from this library, 94 clones contained inserts sized from 80-800 bp, with an average size of 340 bp. Less than 20% of these clones hybridized to human repeat sequences. Seventy-two single-copy clones were further characterized by Southern blot hybridization against a DNA panel of somatic cell hybrids, containing various regions of chromosome 4. Forty-two clones mapped to chromosome 4, of which 8 clones mapped into the relevant 4q35 region. Twenty of these chromosome 4-specific clones were screened against "zoo-blots"; 11 clones, of which 3 mapped to 4q35, identified conserved sequences. This is the first report to describe the isolation of potential expressed sequences derived from the FSHD region. These chromosome region-specific microclones will be useful in the construction of the physical map of the region, the positional cloning of potential disease-associated genes, and the identification of additional polymorphic markers from within the distal 4q region.
Upadhyaya
M
M
Institute of Medical Genetics, Health Park, Cardiff, Wales, United Kingdom.
Osborn
M
M
Maynard
J
J
Altherr
M
M
Ikeda
J
J
Harper
P S
PS
D015415:Biomarkers; D002874:Chromosome Mapping; D002894:Chromosomes, Human, Pair 4; D017124:Conserved Sequence; D015723:Gene Library; D006801:Humans; D009136:Muscular Dystrophies / Q000235:genetics*; D011110:Polymorphism, Genetic
D015415:Biomarkers