Tags

, , , , ,

That’s a mighty scholarly title, but I don’t mean to frighten anyone. I read a brief research summary for an interview last week and it still continues to capture me in the most positive ways. There is, frankly, a lot of ignorance and misconceptions that come about when any typical commoner hears the word, “bacteria,” ranging from “simple scary creatures” to “evil plague massacre,” which honestly only accounts for perhaps 1% of the bacterial biomass. Everyone else in the kingdom is completely innocent of human genocide.

Some scientists say that humans are actually humans + bacteria (which can also be said of many other multi-cellular organisms) because we cannot live a second further without our natural microbial content living on and inside our bodies. Some people wonder how tiny microorganisms find their way into your intestines (called gut microbiota or gut flora), or were they just there before birth. Well, no, the mother’s womb is essentially bacteria-free (with some recent studies indicating deviations), but to answer that question, let’s start with the obvious that doesn’t seem so obvious: your digestive system is external. There’s a massively distorted hollow tube running from your mouth to your anus, so the moment your head meets air and your lungs start bellowing out baby-cries, you already begin your lifelong friendship with free-floating microbes. The gut microbiota continues to form as you start ingesting – or more aptly put, drinking milk – and the microorganisms that you befriend will depend on the types of food you intake.

Lice, though not bacteria, are insects that we affiliate with unwanted pests, but they’re also interesting to discuss, such as head lice, which may be your first thought, and pubic lice, which may be your disturbing read for the day. There is actually a type of pubic lice – the crab louse – that lives only on humans; humans are the only known hosts of this particular species of lice. The crab louse actually shared a common ancestor with a head louse ages ago, when we still looked like proper apes with chests covered in forests. But as we gradually lost our body hair, the population of lice separated into two geographically isolated regions, one ending up on the north pole where hair resides today and the other ending up at the equator where a nice bundle of fibers provides a complete housing ground.

I’ve digressed. Again. Let’s backtrack. Bacteria are awesome. The research lab I read about delved into understanding our survival friends, and exposing their complex and fascinating cellular organization. They aren’t just jumbles of enzymes and tangled DNA; they regulate their cell cycle through protein and mRNA regulation and localization, and are in many ways, just as sophisticated as eukaryotic cells. For example, the bacterium Caulobacter crescentus contains crescentin, a structure much like the intermediate filaments found in eukaryotes, that serves an integral part of the cytoskeleton and is a direct cause for the bacterium’s bent shape. The lab had removed the protein in mutant cells and observed them relax into a straight rod shape instead of the typical sausage-link.

Their more recent findings give light to a DNA partitioning system during cell division. There is a sequence close to the origin of replication on the bacterial genome that has a high affinity for a binding protein. This protein has the ability to hydrolyze ATP on a specific enzyme, which is found located all over the genome, with a “cloud” of higher concentration on the other end of the cell; this enzyme builds filaments, such like the spindle fibers during mitosis. TipN localizes the components to the two poles before cell division, and after DNA replication, the duplicated complex of the partitioning sequence and binding protein move ever so obediently toward the “cloud,” breaking down the filaments as it travels and elegantly partitioning the genome to the new pole. It’s an amazing tactic for readying the cell to enter cytokinesis and split the cellular components evenly. This is admittedly brief and non-descriptive, but my point is the marvelously complicated nature of processes going on in the bacteria – cell division looks spectacularly simple at first glance but not when the mechanics are in full view and understanding.

For any aspiring scientists, details can be found at the lab research page. It’s fun to go on a spiel like this; I’m thinking I should do this more often.