The world's first camelid cDNA library

When some scholar desperate for a PhD topic turns his gaze to the history of research on camels, October 25, 2008 will undoubtedly mark a new chapter in his exceedingly tedious and irrelevant dissertation. After a year of research, the Camel Health Unit successfully synthesized the first camel-related cDNA.

DNA, being the stuff of heredity, is safely ensconced inside the cell nucleus. While this isolation ensures its integrity, it also makes DNA kind of useless. In order to get something done, the cell must transcribe instructions (genes) from DNA into RNA, which then passes out of the nucleus to be translated into proteins. These proteins are what actually do things in the cell. So if you want to study how genes get expressed rather than just how they get passed on, RNA is of far more interest, because it reflects exactly which instructions are being carried out when. But DNA is easier to study, so we collect the active RNA, copy it back into DNA, and call it cDNA.

Once you have cDNA, you can do all sorts of cool and godlike things. We're looking at the parasite Haemonchus contortus, a worm living in the camel digestive tract that feeds by digesting hemoglobin. We isolated the H. contortus RNA that codes for the protein responsible for digestion and copied it back into cDNA. Next, we'll insert that cDNA gene into the genome of a small bacteria (called a vector) and see if the genetically modified bacteria can digest hemoglobin. We'll then use that bacteria to design a simple diagnostic that would detect the presence of the hemoglobin-digesting protein in camel blood.

An interesting sidenote: even this advanced work has at its root the same large-level changes I've seen throughout Rajasthan. Desertification and overpopulation have led to a reduction in the quality topfeed (trees, tall shrubs) that camels prefer, forcing them to compete with sheep, goats, and cows for low-level grazing. This means that H. contortus, usually only found in sheep here, has moved to camels as the animals are exposed to feces-covered groundfeed.

Camel nutrition

I have discovered the best way to pass time at the NRCC when I'm not helping in the lab, working on some stats, studying in the library, or searching Google for naked pictures of Sarah Palin. I stick my head out the door, listen for a moment, and then try to find the camel making the most absurd noises.

Yesterday the nastiest grunting I'd ever heard came wafting over from the Nutrition experiment corral and I enthusiastically made my way over to see just what tricks the Grand Inquisitor had devised for this poor camel. My stomach turned (in sympathy, too) when I realized that the technical team was in the process of collecting ruminal fluid.

In order to extract the stinky yellow juice from an organ located at the bottom of a 80 centimeter esophagus, a garden hose was connected to an imposing air pump coughing out plumes of black smoke. The camel was so doped up on xylazine it couldn't hold its neck up, but it still had the sense to try to bite the hand that choked it. Finally, a few centiliters of fluid were extracted and the camel left to enjoy the rest of its trip.

I wasn't sure whether to cry or laugh at the pitiful position the animal adopted at the end of the procedure.

Camel pox

There is a small corral isolated from the rest of the facility where those camels requiring medical attention are kept. Right now it is home to several animals who have contracted camel pox. Several months ago the disease swept through the herd, infecting those animals who had not yet been exposed. While the very young usually survive the infection, older camels require much more attention (much like chicken pox in humans). Here, you can see the impending eruption of the pox on an older animal.