March 11, 2005 | David F. Coppedge

Bacterial Engineering On Par With Higher Life

Bacteria aren’t the simple life-forms microbiologists used to envision, writes Zemer Gitai in Cell.1

Recent advances have demonstrated that bacterial cells have an exquisitely organized and dynamic subcellular architecture.  Like their eukaryotic counterparts, bacteria employ a full complement of cytoskeletal proteins, localize proteins and DNA to specific subcellular addresses at specific times, and use intercellular signaling to coordinate multicellular events.  The striking conceptual and molecular similarities between prokaryotic and eukaryotic cell biology thus make bacteria powerful model systems for studying fundamental cellular questions.   (Emphasis added in all quotes.)

This is different from the traditional picture of bacteria, he elaborates:

This traditional perspective [of bacteria as fundamentally different from eukaryotes (i.e., simpler] changed significantly in the past decade with dramatic advances in our understanding of bacterial cell biology.  Work in multiple species has demonstrated that bacteria are actually highly ordered and dynamic cells.  Much like their eukaryotic counterparts, bacterial cells are capable of polarizing, differentiating into different cell types, and signaling to each other to coordinate multicellular actions.  The more recent surprises come from advances in fluorescence microscopy, demonstrating that bacterial cells exhibit a high level of intracellular organization.  Bacteria dynamically localize proteins, DNA, and lipids to reproducible addresses within the cell and use this dynamic organization to tightly regulate complex cellular events in both space and time.

Gitai provides detail on the following examples: (1) Bacteria have homologs of the eukaryotic cytoskeleton, (2) bacterial cells are subcellularly organized (i.e., are not lacking organelles or a nucleus-like function), (3) several mechanisms underlie bacterial subcellular organization, and (4) bacteria are able to engage in multicellular activities.
    “Bacteria are wondrously diverse and resourceful, occupying virtually every environmental niche imaginable,” he writes in conclusion. 

1Zemer Gitai, “The New Bacterial Cell Biology: Moving Parts and Subcellular Architecture,” Cell, Volume 120, Issue 5, 11 March 2005, Pages 577-586, doi:10.1016/j.cell.2005.02.026.

Sadly, Gitai assumes evolution in various places, but not with evidence: only with inference, in spite of the evidence.  For example, “If systems are similar due to convergent evolution, they can point us toward nature’s optimal solution to a problem, whereas, if they differ due to divergent evolution, they can identify the basic rules that have remained intact.”  Those are pretty big ifs.  What if they are both due to intelligent design?  He would never think of asking the right questions, even though he has no answers.  “The evolutionary relationships between actin, MreB, and ParM remain unclear, as they are similarly divergent from each other,” he drones in one place, and “The interrelatedness of these spiraled structures remains unclear,” in another.
    The rest of his references of evolution only assume it.  He has convergent evolution (read: simultaneous miracles) happening all over the place.  He personifies nature in the previous quote: “nature’s optimal solution to a problem.”  Now that we know who the Darwin Party’s goddess is – Tinkerbell (see 03/08/2005 commentary) – we wish him luck getting optimal solutions from her.  Tinkerbell’s technique is to zap organisms with mutations using her magic wand.  But she flitters about from place to place with no goal in mind, only hoping that the bullets she fires into the machinery will make things run better.  You know the game is rigged when two separate organisms arrive at the same optimal solution.  Calling it convergent evolution will not fool the perceptive viewers of this magic kingdom; they know somebody is behind the scenes controlling the show.
    For this reason, we have to give this story both the Amazing and Dumb awards.  Amazing for the bacteria, Dumb for the human.

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