FIG 4.

Clinical R. mucilaginosa strain 201 produces larger capsules than environmental R. mucilaginosa strain 115. The same experiments were performed as described for Fig. 3 for the following strains: H99 C. neoformans, ARY 115 environmental R. mucilaginosa, and ARY 201 clinical R. mucilaginosa. After incubation of equivalent numbers of cells in PBS, DMEM, Sabouraud, or 10% diluted Sabouraud media, with or without CO₂ and with or without 10% FCS (as described in Materials and Methods and the Fig. 3 legend), samples were mixed with India ink. Four to eight pictures were taken for each of the 16 conditions for each of the three strains to capture random and representative images. The diameters of the cell and capsule and the cell alone without capsule were measured in ImageJ for as many cells as could be cleanly determined in each image. The ratios of cell volume with capsule (V_Tot) and cell volume without capsule (V_cell) are shown in gray dots. The bottom and top edges of the box plot correspond to the first and third quartiles of the data, respectively, with the vertical lines corresponding to no greater than 1.5 × the interquartile range. The middle line of each box represents the median of the data. Each condition was well represented by multiple measurements, with the exception of strain 201 in PBS, in which too few cells were noted with measureable contrast.