New classes of common fragile sites induced by 5-azacytidine and bromodeoxyuridine

Abstract
Two new classes of common fragile site seen in chromosomes from blood lymphocyte cultures are reproted. The first cláss is induced in bands 1q42 and 19q13 by 5-azacytidine (5-AZA). Maximum induction of these fragile sites occurs when the 5-AZA is added 5–8 h prior to harvest. The second class is induced in bands 6q13, 9p21, and 10q21 by bromodeoxyuridine (BrdU). In this instance maximum induction occurred if the BrdU was added 4–6h prior to harvest. The known fragile sites, both rare and common, are summarised.