Exuperantia from nurse cell helps bicoid RNA (green) move to the oocyte anterior.
Theurkauf/Elsevier
Bicoid mRNA is an anterior determinant for fly development that is produced in nurse cells before moving into the neighboring oocyte. In the simplest models, the mRNA was thought to use polarized microtubules to move to the anterior of the fly oocyte.
Now William Theurkauf and colleagues (University of Massachusetts Medical School, Worcester, MA) show that such a simple model will not work, because the mesh of oocyte microtubules is largely unpolarized. Instead, bicoid mRNA picks up transport factors in the nurse cells, before entering the oocyte and using those factors to mediate anterior localization, possibly on a polarized subset of microtubules. Without the factors, the mRNA can move on microtubules but its movement is undirected.
Byeong Cha in the Theurkauf lab began his experiments by injecting in vitro transcribed...
