Correction

Data were collected and analyzed as in Table III. Analysis indicates media conditions affect the ability of the ΔcortI stain to grow. Data were compiled for two independent transformations for cortI 2A19 pLD1A15SN and 2B19 pLD1A15SN. Since the ΔcortI was generated with the G418-resistance marker, cortI 2A19 and 2B19 pLD1A15SN had to be transformed with a cocktail of plasmids that included a blasticidin resistance plasmid to select for cells that acquired DNA. Cells were then grown in suspension culture to select for rescue. Both plasmids showed rescue with identical time courses. Data of growth of cells in Hans' enriched HL-5 media also includes results from cells transformed with a 2B19 expression construct that contains a blasticidin resistance marker. The appropriate vector backbone was transformed into the wild-type and ΔcortI cells (denoted control plasmid). Comparisons were only made between cells with the appropriate control plasmid. Only cells carrying the pLD1A15SN-derived plasmids were assayed in standard HL-5 media. For cells grown in standard HL-5 media, differences in all growth parameters were significant for wild-type and rescued strains compared to the mutant (one-tailed t test: growth rate, P < 0.00005; R value, 0.01 < P < 0.025; and saturation density, P < 0.00005). The wild-type strain for these experiments was the Ax2-214 strain.