On the reproductive mechanisms of Gram-positive protocells

Bacterial protoplasts are believed to reproduce in a haphazard manner. Their unregulated method of reproduction is considered the simplest of all known forms of cell replication. In the present study, we attempted to understand the evolutionary significance and physiochemical mechanisms behind this process. Here we transformed a Gram-positive bacterium into sack of cytoplasm, incapable of regulating either its morphology or reproductive processes. As such primitive (proto)cells devoid of molecular biological processes could have been native to early Earth, we grew these cells under environmental conditions of early Earth. We then monitored these cells at regular intervals to understand if they can grow and reproduce under these conditions. In our incubations, cells exhibited a multi-stage reproductive cycle resulting in viable daughter cells. What was previously thought to be a chaotic reproductive process, could in fact be well explained from a physicochemical perspective. Both morphology and reproductive process of these cells were determined by chemical and self-assembling properties of their cell constituents rather than the information encoded in their genome. Despite its haphazard appearance, we propose that the reproductive process of bacterial protoplasts is better optimized for environmental conditions of early Earth and could be reminiscent of protocell reproductive processes. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/470039v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@1c0b119org.highwire.dtl.DTLVardef@1ab1272org.highwire.dtl.DTLVardef@4813d7org.highwire.dtl.DTLVardef@eb482_HPS_FORMAT_FIGEXP M_FIG C_FIG