FIG. 1.

Bdellovibrio filamentous growth-phase cells septate synchronously within the bdelloplast, forming both odd and even numbers of progeny. (Aa) Frequency measurement of the number of mature Bdellovibrio cells within 146 E. coli S17-1::pMAL-p2_mCherry fluorescent bdelloplasts. Average prey cell length was 4.67 μm ± 1.37 and width was 0.97 μm ± 0.09 (n = 167). (Ab) Examples of septated and mature growth-phase Bdellovibrio cells within fluorescently labeled bdelloplasts, with images used to illustrate frequency plot shown in panel Aa and described above. (Ba) Sketch showing key points in Bdellovibrio cell development within a bdelloplast. (Bb and c) Selected frames from time-lapse movies showing synchronously dividing growth-phase cells in fluorescent bdelloplasts. (Bd) Selected frames from time-lapse movies showing two synchronously dividing growth-phase cells forming different amounts of progeny (3 and 4) within a fluorescent bdelloplast. Fluorescence mCherry activity is false-colored green for clarity. Bars = 1 μm. Selected time-lapse movies are provided in Movies S1 and S2 in the supplemental material.