Open AccessHomologous subfamilies of human alphoid repetitive DNA on different nucleolus organizing chromosomes.
Author(s) -
Arne Lund Jørgensen,
Christopher J. Bostock,
A. Leth Bak
Publication year - 1987
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.84.4.1075
Subject(s) - biology , subfamily , genetics , ecori , chromosome 22 , base pair , chromosome , restriction enzyme , repeated sequence , dna , microbiology and biotechnology , genome , gene
The organization of alphoid repeated sequences on human nucleolus-organizing (NOR) chromosomes 13, 21, and 22 has been investigated. Analysis of hybridization of alphoid DNA probes to Southern transfers of restriction enzyme-digested DNA fragments from hybrid cells containing single human chromosomes shows that chromosomes 13 and 21 share one subfamily of alphoid repeats, whereas a different subfamily may be held in common by chromosomes 13 and 22. The sequences of cloned 680-base-pair EcoRI fragments of the alphoid DNA from chromosomes 13 and 21 show that the basic unit of this subfamily is indistinguishable on each chromosome. The sequence of cloned 1020-base-pair Xba I fragments from chromosome 22 is related to, but distinguishable from, that of the 680-base-pair EcoRI alphoid subfamily of chromosomes 13 and 21. These results suggest that, at some point after they originated and were homogenized, different subfamilies of alphoid sequences must have exchanged between chromosomes 13 and 21 and separately between chromosomes 13 and 22.