Some Science

It seems to rain mostly at night here in Grenoble. Even though dark, ominous clouds visibly creep across the northwestern mountains, it never seems to rain substantial until nighttime. It's kind of like an empty threat that looms throughout the day. But right now there are thunderstorms in the not so distant mountains and I can hear rain outside. OH, there's a flash in the sky! These storms are as spectacular as the ones' in Tucson, but they are still nonetheless fun to watch if they are "your-sort-of-thing." Either way, it's a good chance to sit down and contemplate on some of the new sciences I've been introduced to here working with the Vivaudou group. I can't say I'm an expert - in training I'm more knowledgeable about marine chemistry (undergraduate work) and am now becoming more knowledgeable about lipids, sensors, experimental design, etc. - but at least I can provide a cursory discussion of the technique.

In the Vivaudou lab, ICCR's are expressed in Xenopus oocytes (these are frog eggs). Frog's from the Xenopus genus are relatively large frogs with claws. Their eggs are routinely used in protein expression studies because one can inject mRNA or exogenous DNA coding for a particular protein of interest and get protein expression (pretty cool if you ask me). See the citation below for the fundamental paper. The are a number of interesting consequences, such as the ability to analyze isolated receptors or ion channels; mutating receptors or channels and then expressing them in order to understand structure and function; and study receptor-ligand interactions.

The Xenopus oocyte are about 1 mm in diameter and are thus visible to the naked eye. There are different stages of ooctyes, but researchers primarily use stage V and VI. Here's a site with some good pictures of frogs and eggs. In stage V and VI, the oocyte has two distinct hemispheres, one corresponding to the animal pole (dark) and one corresponding to the vegetal pole (light). The vitelline membrane, a thin, clear membrane, encases the two hemispheres and provides the oocyte with some structural support. Further encasing the vitelline membrane is the follicle cell layer, which carries blood vessels. In a way, they remind me of miniature pearl tapioca.

That's all for now, more to come later.

Gurdon, J.B., Lane, C.D., Woodland, H.R., Marbaix, B. Use of frog eggs and oocytes for the study of messenger RNA and its translocation in living cells. Nature (1971), 233, 177-182.