Analysis of a human mutant centromere: Key to the identification of essential centromeric sequences
- Life Technologies, Inc., Gaithersburg, MD (United States)
- Univ. of Milan (Italy)
Three elements are required for replication and segregation in human chromosomes. Of these, human telomere and origin of replication sequences have already been identified. The essential centromeric sequences necessary and sufficient for segregation are not yet known. To this end the molecular analysis of rare human centromere mutants may be extremely important. Chromosomes with atypical centromeres may be found in human karyotypes and can be used for studies of the molecular organization of the human centromere. We are currently studying the centromere of a stable, apparently acentric, marker chromosome. By using chromosme painting we established that the marker chromosome was derived from the distal region of chromosome 14. In situ hybridization analysis of this minichromosome did not show evidence of alpha satellite sequences which are present in all human centromeres or beta satellite DNA also found in many human chromosomes. CREST autoimmune sera, known to recognize the CENP-B centromeric protein, highlighted the marker`s kinetochore. This finding strongly indicated the presence in the marker chromosome of DNA sequences essential for segregation. Despite its origin, the marker was negative for 14/22 centromere-specific alphoid DNA. In an attempt to identify the origin of the marker centromeric sequences we amplified the flow sorted marker chromosome by degenerate oligonucleotide-primed-polymerase chain reaction (DOP-PCR). Probes generated under different conditions highlighted either the 14q32-qter region, the pericentromeric region of chromosome 19, or the centromeric region of chromosome 18. We speculate that a low copy number of sequences found in the peri-centromeric region of chromosome 19 and the centromeric region of chromosome 18 are present on chromosome 14 and generated a functional centromere through a complex rearrangement.
- OSTI ID:
- 133665
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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