Three different repeat sequences have been mapped within the cloned EcoRI fragments that Contain the adult β-globin genes from the BALB/c (Hddd) mouse. One sequence, "a", occurs 1.5-2 kb 3′ to the β-major gene. A second, "b", is found 4kb 5′ and 7.5kb 3′ to the β-minor gene. The 14kb EcoRI fragment bearing the β-minor gene carries at least one additional repetitive element, "c". Probing a BALB/c DNA library with each repeat has demonstrated that these sequences are moderately to highly repetitive and are extensively interspersed with each other throughout the genome. In addition, repeats "a" and "b" are preferentially found in satellite and main-band DNA, respectively. The occurence of these repeats elsewhere in the β-globin cluster was demonstrated by probing the non-adult globin clones with each repeat. The arrangement of these repeats around the non-adult genes is 5′-"b"-"b"-εy-βh1-βh2-"c"-βh3-3′. Probing the C57BL/10 (HbbS) adult gene clones with these repeats demonstrated that the distribution of these sequences in the adult region of these two haplotypes is essentially the same.
ASJC Scopus subject areas