Tuesday, October 25, 2011

Halloween winemaking magic at Bruliam Wines

Just in time for Halloween, Kerith Overstreet at Bruliam Wines has a great blog post this week about working with her spooky 2011 harvest (beating it into submission, actually).  Sounds like a challenging year!  She describes the redox chemistry that goes on during the early fermentation process and actually has a graph from her lab!  I first blogged about the magic of winemaking after Kerith's great talk on the subject (here is my post) and even she refers to the process as magic in her latest post (but she also refers to wife swapping, Alanis Morissette, and Hanukkah miracles, so who knows what state of mind she was in as she wrote this).  Anyhow, a very fun, informative read directly from the mysterious front lines of winemaking.  Enjoy it with a glass of good Cabernet, the official wine of the dead.

Keriths latest blog post:  (link)

Thursday, October 20, 2011

21st Century mummy

Just a quick pointer to a cool article on a recent attempt at mummification (here's the link). Stephen Buckley, a chemist at York Univeristy in England, has spent two decades studying how ancient Egyptians made mummies.  He studied tissue samples and chemical traces left on canopic jars in an effort to reproduce the method.  He then tested the process in his shed, using pig's legs as a proxy for human flesh (there's a DIYbio project for you!).  I'm not sure if this guy is married, but even here in the Dark Lab, this work would be pushing the limits.  Anyhow, this year he felt that he was ready for prime time.  He placed an ad looking for suitable volunteers and the lucky person was... Alan Billis, a London cab driver.  Terminally ill with lung cancer, he went through the mummification process after he died. By all accounts, it was a success and the body will be kept for at least a year to study.  Hopefully, Alan is hanging out with a bunch of cool, Egyptian princesses.  Thousands of years from now, archaeologists will argue over whether our society placed a high value on cab drivers, or if Mr. Billis was simply a member of the ruling elite.  They will come up with grand theories on how he lived, how he died, and why he was the only surviving mummy of the period.  Should make for an interesting read.

Cat mummy at the British Museum (link)

To me, it is truly amazing that with all of today's technology, it is difficult to reproduce the mummification procedure.  The Egyptians likely had years of empirical data to build from and since it was considered a sacred ritual for the upper class, there was significant motivation for young priests to be good at making a mummy.  I can see a room full of young mummification interns, trying to preserve rats or some other suitable test animal.  After months of work, the mentor unwraps the package, only to find a rancid, decomposing corpse. "Aw, man," the student whines (or whatever the angsty teen expression was at that time).  He then slouches his way over to the stone quarry.

Wednesday, October 5, 2011

A gene important for creating zombie caterpillars

Advancements in zombie science are coming fast and furious!  An email from a colleague (and fellow reader) noted that I missed a recent article in the journal Science concerning zombies.  The article, titled "A Gene for an Extended Phenotype", seemed pretty innocuous, however, after going back and reading it more carefully it turned out to be a pretty cool discovery.

First, a bit about zombie caterpillars.  There have been several documented reports of zombie-like behavior in moth larvae.  This report is focused on the infection of the gypsy moth (Lymantria dispar) by a baculovirus (known as LdMNPV).  During the various stages of molting, larvae typically hang out on the ground and away from The Very Hungry Birdie, but climb up into the trees at night to feed on leaves.  After infection by the baculovirus, their behavior changes (noticing a pattern here?).  As the virus replicates and ravages the inside of the caterpillar, the infected host climbs up into the leaves during the daylight hours and eventually dies.  The body then liquefies, and virus-laden particles rain down on the uninfected victims below.  Yeah, you can't script horror much better than that.

Ok, so Hoover et al. (from Penn State, see abstract) were interested in identifying which genes were important for the change in behavior.  To do this, they infected caterpillars with wild type baculovirus, as well as virus that had been genetically engineered to be missing certain genes.  The caterpillars were placed in 1 liter soda bottles equipped with a fiberglass screen for climbing (in true DIYbio fashion!!).  Interestingly, when a gene called egt was removed, the caterpillars died at ground level, suggesting that the behavioral control of the virus had been altered.  To make sure it wasn't an artifact of the mutated virus, they re-engineered the mutated constructs so that the egt gene was present again and the zombie caterpillars climbed up the mesh and died.  It would appear that the egt gene in the virus has evolved to make the caterpillars engage in high-risk behavior, and to place the caterpillars in a location where rain/gravity/hungry birdies can maximize viral spread. Genius.

The next step is to figure out the mechanism.  Interestingly, Hoover et al. mention that the egt gene encodes an enzyme which deactivates a hormone (20-hydroxyecdysone) involved in the process of molting.  It is intriguing that the virus blocks the molting process in order to give itself time to replicate inside the host, but it was hard for me to understand how the modification of the hormone leads to behavioral changes.  Perhaps entomologists already know that part.  Coincidentally, the hormone is also reported to have a variety of biological effects in humans, even though we do not molt and lack the endogenous receptor. What would the modified enzyme do in a human?  Until we find this stuff out, it's probably a good idea to check the trees around your house, particularly if you hear a dripping sound... and if your neighbor has been missing awhile.

Yes, there are zombies all around us.