Ulrike Gaul and fly compartments
Ulrike came from Rockefeller University to talk about how Drosophila flies develop.
On of the big questions in biology is how a clump of almost-identical cells (an embryo in it's early stages, say) becomes something incredibly structured (a human body, say) with organs, tissues, and limbs all in the 'right' place. Morphogenesis is the study of this process.
In the last decade or so, biologists have started to understand the genes involved in this process and how they work. As in much of biology, a lot of the work has been done on Drosphila flies (get your own batch here). When an egg is formed, the mother marks opposite ends (poles) of it with different RNA molecules. I'm not sure how this is done, but this creates a gradient in the egg. One pole has a high concentration of the one molecule type and a low concentration of the other, and the other pole has the reverse. Between the poles, these concentrations vary, going from high-to-low or low-to-high. This means that when the egg is fertilized and starts splitting and developing, each of the daughter cells will have a slightly different amount of each of the RNA molecules. These concentrations are directly related to the position of the daughter cell relative to the two poles. In other words, the amount of each RNA in a particular daughter cell depends on where that daughter cell is between the two opposite poles that the mother originally marked with different the RNA molecules. The concentration of each RNA then affects which genes are expressed and which are inhibited in each daughter cell. Bingo, we have the beginnings of structural organization!
Beautiful words/phrases
Names of mutant flies: hunchback, giant, kruppel, knirps, tailless, even-skipped, hairy, runt, engrailed, wingless, hedgehog
On of the big questions in biology is how a clump of almost-identical cells (an embryo in it's early stages, say) becomes something incredibly structured (a human body, say) with organs, tissues, and limbs all in the 'right' place. Morphogenesis is the study of this process.
In the last decade or so, biologists have started to understand the genes involved in this process and how they work. As in much of biology, a lot of the work has been done on Drosphila flies (get your own batch here). When an egg is formed, the mother marks opposite ends (poles) of it with different RNA molecules. I'm not sure how this is done, but this creates a gradient in the egg. One pole has a high concentration of the one molecule type and a low concentration of the other, and the other pole has the reverse. Between the poles, these concentrations vary, going from high-to-low or low-to-high. This means that when the egg is fertilized and starts splitting and developing, each of the daughter cells will have a slightly different amount of each of the RNA molecules. These concentrations are directly related to the position of the daughter cell relative to the two poles. In other words, the amount of each RNA in a particular daughter cell depends on where that daughter cell is between the two opposite poles that the mother originally marked with different the RNA molecules. The concentration of each RNA then affects which genes are expressed and which are inhibited in each daughter cell. Bingo, we have the beginnings of structural organization!
Beautiful words/phrases
Names of mutant flies: hunchback, giant, kruppel, knirps, tailless, even-skipped, hairy, runt, engrailed, wingless, hedgehog
