TABLE 4.

Expression of Tn5lac insertions during development on d-cycloserine^a

Strain	Tn5lac insertionb	Timing (h)c	Dependenced	CF + d-cycloserinee
DK5285	Ω4491	0	asg	Same
DK4300	Ω4408	1	Partial bsg	Same
DK4521	Ω4521	2	asg	Same
DK5206	Ω4455	3	Partial bsg	Early
DK4469	Ω4469	5	Partial bsg	Same
DK4290	Ω4273 (tps)	5	asg	Same
DK4514	Ω4514	9	Partial csg	Early
DK5274	Ω4414	10	bsg	Same
DK4368	Ω4403	15	csg	Same
DK5204	Ω4435	25	csg	Same
DK4293	Ω4401	30	csg	Same

^aAll strains are in a DK1622 background. The strains were incubated at 28°C for development as described in Materials and Methods. Plates were monitored for appearance of a blue precipitate. d-Cycloserine was added at 15 μg/ml. 

^bΩ4408 is a mutation that causes delayed aggregation. Ω4414 is a mutation that causes poor aggregation. The rest of the Tn5lac insertions have no developmental defect (30). 

^cThe time at which Tn5lac insertions are expressed is taken from Kroos et al. (30) and was determined by spectrophotometric assays of β-galactosidase in extracts of developing cells. 

^dThe expression of Tn5lac insertions in Asg, Bsg, and Csg mutant backgrounds was monitored to determine the effects of these mutations on the expression of the Tn5lac insertions (31, 34). 

^eTime at which blue precipitate was detected in comparison to CF plates (no d-cycloserine). As described in Materials and Methods, the plates were examined daily for the appearance of blue precipitate. This method is not as sensitive as that used by Kroos, et al. (30) to determine the time at which the genes are first expressed (see note b), but the sensitivity is sufficient to detect significant differences in the onset or level of expression.