Nematodes: still an interesting animal

CrawlingCelegansEmily Vandement (12:00 Micro) found an article in Science Daily  that talks about the use of a microscopic roundworm to study basic questions about developmental biology.  I have to admit that I’ve always had a fondness for nematodes, and am happy to reuse this image file. An article I found a year or so ago described how a mold that eats these little guys also produces a potential anti-cancer factor. Another article from further back in the BIO230 archives talks about how a fluorescent bacterium and these nematodes share a symbiotic relationship (SERIOUSLY–this one is way cool!) And finally, roundworm infections in times when we had more dirt in our diets may have protected the human body against more serious infectious agents. Enough about stuff I found, here’s Emily’s story:

Two weeks into microbiology and we have met many microorganisms through Prof. Singleton’s lectures.  Bacillus cereus, Staphylococcus, Listeria monocytogenes,  Salmonella enterica, Clostridium botulinum, and a few others, all of which harm the human body.  We discussed what the bacterium do to those they infect, how to identify them, and a few key ways of terminating their existence upon infection.  But me, taking anatomy and physiology, wondered the physiology portion of the microorganisms.  How do they function and metabolize?  How is it that bacterium is able to sense when harsh conditions surround it, causing some to form endospores?  To find out more information on such questions I looked to the science news, finding an article in Science Daily.

nematodeAn organism Caenorhabditis elegans, a simple nematode, has recently been studied to better organize and understand the nervous system of microorganisms.  This nematode is found in rotting soil and is tough to find due to its transparency.  It contains only 302 neurons connected by a network of 800 synapses.  Now compare the 302 neurons of the nematode to the average adult human brain, which has been found to consist of over 86 billion neurons, each neuron containing hundreds to thousands of synapses.  Imagine having every nerve impulse mapped out for the human body!  Scientific advances would flow from that finding like Group A Streptococcus when infected in the skin!

However, to get to the point where the human nervous system can be mapped out baby steps must occur, beginning with the mapping of simple bacteria such as C. elegans.  Foreign scientists at Vienna’s Research Institute of Molecular Pathology, Max Perutz Laboratories, and a portion of the University of Vienna have been working together to understand the microorganisms neurons and synapses, collaborating and contributing to the finding of a new microscopic imaging method.  The mapping of C. elegans’s nervous system is slow in the making.  Previously the neurons and synapses of C. elegans had not been mapped out due to the limited imaging technique.  With the goal of mapping the nematodes nervous system, they found that neurons can be visualized via a high powered microscope when the C. elegans is tagged with fluorescent protein.  When the protein binds with calcium it is able to show the activity of such nerve cell.  After a few tries, the scientists were able to improve their technique by adding the calcium sensor into the nuclei instead of the cell as a whole.  This triggered the ability to decipher the difference between the impulses in the nematodes brain, identifying single neurons and their impulses.  Above is the WF-TeFo microscope picture of a nematode’s frontal segment, the green representing the neurons in the worm’s brain.  The finding made by these scientists still requires improvement because only about 70 percent of the nerve cells were able to be recorded.  This large step toward mapping the nematodes neurology will aid in the long term development of all areas of science.

The questions posed previously are still unanswered but the work done by the scientists are making moves toward a concise explanation for the physiology of bacterium.


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on September 11, 2013, in Guest Post, Microbes in the News and tagged , . Bookmark the permalink. 2 Comments.

  1. Sydney Brenner, who was awarded the 2002 Nobel Prize in Physiology or Medicine for his work on C. elegans Is one of my science “heroes.” Brenner is a remarkable scientist, in part because he was one of the major early & successful workers in molecular biology. Legend has it that he was bored with that field & was looking for a more challenging problem. So, he decided to trace out the developmental pathway of every cell in C. elegans. A lot of people though he was crazy, but he succeeded! His story is a great one about science; take on the problems that every one else thinks are impossible. That’s my $0.02 worth.

    • As a bookend to Brenner’s recognition with a Nobel Prize in 2002, just 4 years later the Nobel Prize in Physiology or Medicine was awarded to Andrew Fire and Craig Mello for their discovery of RNA interference, which they characterized extensively using C. elegans. Fire had trained in Cambridge with Brenner during his scientific education, and as a result is well versed in worm biology. I recall reading the RNA interference papers while as a postdoc–it wasn’t all that long ago, and although the phenomenon might at first glance seem to be an interesting aspect of the biology of the nematode, RNA interference is actually one on the few fields that has gone from a fascinating observation in basic lab science to something that is having a profound and wide reaching impact on patient treatments, and has done so in an incredibly short time frame.

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