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Title: Isolation, characterization, and regional mapping of microclones from a human chromosome 21 microdissection library

Journal Article · · American Journal of Human Genetics; (United States)
OSTI ID:7224334
; ; ; ; ;  [1]; ; ;  [2];  [3]
  1. Eleanor Roosevelt Inst., Denver, CO (United States)
  2. Univ. of Colorado Health Sciences Center, Denver, CO (United States)
  3. Univ. of California, Los Angeles (United States)

Thirty-four unique-sequence microclones were isolated from a previously described microdissection library of human chromosome 21 and were regionally mapped using a cell hybrid mapping panel which consists of six cell hybrids and divides chromosome 21 into eight regions. The mapping results showed that the microclones were unevenly distributed along chromosome 21, with the majority of microclones located in the distal half portion of the long arm, between 21q21.3 and 21qter. The number of unique-sequence clones began to decrease significantly from 21q21.2 to centromere and extending to the short arm. This finding is consistent with those reported in other chromosome 21 libraries. Thus, it may be inferred that the proximal portion of the long arm of chromosome 21 contains higher proportions of repetitive sequences, rather than unique sequences of genes. The microclones were also characterized for insert size and were used to identify the corresponding genomic fragments generated by HindIII. In addition, the authors demonstrated that the microclones with short inserts can be efficiently used to identify YAC (yeast artificial chromosome) clones with large inserts, for increased genomic coverage for high-resolution physical mapping. They also used 200 unique-sequence microclones to screen a human liver cDNA library and identified two cDNA clones which were regionally assigned to the 21q21.3-q22.1 region. Thus, generation of unique-sequence microclones from chromosome 21 appears to be useful to isolate and regionally map many cDNA clones, among which will be candidate genes for important diseases on chromosome 21, including Down syndrome, Alzheimer disease, amyotrophic lateral sclerosis, and one form of epilepsy.

OSTI ID:
7224334
Journal Information:
American Journal of Human Genetics; (United States), Vol. 51:2; ISSN 0002-9297
Country of Publication:
United States
Language:
English