Table 3.

Localization of an Excised Subtelomeric Origin

Colocalization of ARS501 signals with Tel V-R			Localization of ARS501		n(nuclei scored)
% peripheral	% internal
α-factor	−gal	90%	73	27	42; 48
α-factor	+gal	11%	56	44	37; 66
nocodazole	−gal	92%	81	19	24; 57
nocodazole	+gal	18%	56	44	22; 48

Subnuclear localization of the 30-kb ARS501 cassette was quantified for its position relative to either the telomere proximal locus on Chromosome V or to the nuclear periphery, as identified by antinuclear pore. Data were obtained from experiments like those described in Fig. 7b–e, in which the ARS501 cassette was excised. Distance measurements between the maxima of two signals were performed using the line profile tool of LSM510 Confocal Software. Signals ≤300 nm apart were scored as colocalizing. For subnuclear localization of the ARS501 signal, the nucleus was divided in two zones of similar area: peripheral and internal (Fig. 3 b, and see Materials and Methods). Right column: n _{colocalization}, n _{peripheral internal}. Analysis using a standard χ² test revealed that the localization of ARS501 was significantly different from random localization before (P < 0.001) but not after excision.