© 1992 Oxford University Press
RESEARCH-ARTICLE |
Microdissection of a human marker chromosome reveals its origin and a new family of centromeric repetitive DNA
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine 1011 NW. 15th Street, Miami, FL 33136-1019, USA 1Institute for Medical Biology and Human Genetics, University of Graz Harrachgasse 21/8, A-8010 Graz, Austria
* To whom correspondence should be addressed
Received July 20, 1992; Revised October 28, 1992; Accepted October 28, 1992
A series of procedures including chromosome microdissection, sequence-independent PCR, Southern-blot-hybrid-selection- cloning and sequencing of microdissected DNA-library members were used to analyze DNA from a familial marker chromosome centromere and to determine the origin of the marker chromosome in the case of a live-born, tetraploid human infant. A new family of repetitive DNA, termed sn5 satellite, was sequenced and characterized by DNA hybridization. The sn5 satellite family appears to be primatespecific and shows a chromosome-specific distribution which parallels that of alpha satellite suprachromosomal family 2. This suprachromosomal classification is based on sequence similarity of centromeric alpha satellite DNA within particular groups of chromosomes. It has been postulated that the similarity of aiphold sequences within each of the three suprachromosomal families results from homologous exchanges between nonhomologous chromosomes within each family. The parallel distribution of sn5 satellite sequences at the centromeres of chromosomes of aiphold suprachromosomal family 2 suggests that homologous exchanges between non-homologous chromosomes may be the basis of simultaneous chromosome-specific sequence conservation for multiple centromeric satellite DNA families.