Table 1. Frequency of HOAP staining on broken chromosomes.

Time after heat shock (hr)	Nuclei with acentric			Nuclei lacking acentric
	Total	Acentric positive	Broken end positive	Total	Broken end positive
8	28	18	7	3	1
16	138	102	16	74	7
24	58	39	14	30	3
40	23	15	5	19	2
72	13	12	1	27	1
Total	260	186	43	153	14

Nuclei that carried a broken chromosome were scored for HOAP staining on the broken chromosome end, and on the acentric chromosome (if present) as a control for staining efficiency. The larvae that were examined carried 70FLP3F on their X and the inverted FRT-bearing element FrTr1D (at 72D1 on 3L). They were heat shocked at 38° for 1 hr, and dissected at various times after heat shock.