We are interested in how spatial information is created within a single cell. Extrinsic factors such as cell-cell contacts can provide a cell with spatial cues that influence the distribution of molecules and cell shape. However, some cells apparently do not rely on such extrinsic factors. For example, we have demonstrated that in cultured Drosophila neurons several membrane proteins localize to specific segments of axons without cell-cell contacts. One of our goals is to unravel the intrinsic programs that achieve such intra-cellular, or rather “intra-axonal”, patterning. As has been shown in the patterning of early Drosophila embryos, the patterns could be coded by gradients of molecules within axons. Alternatively, neurons could use temporal information, such as the timing of gene expression during axonal elongation, to specify the spatial patterns along axons. Weare addressing these possibilities by using a variety of imaging techniques, single cell manipulation, and Drosophila genetics. We also seek to address the functional significance of intra-axonal patterning: how sub-axonal localization of membrane proteins contribute to the formation and function of the neural network.

Localization of fluorescently-tagged membrane proteins in cultured neuron. Two axon guidance receptors (Derailed, ROBO3) localize in a complementary manner in sub-axonal compartments.
初代培養下のニューロンにおける蛍光タグされた膜タンパク質の軸索内局在．２種の軸索ガイド受容体 (Derailed, ROBO3) は相補的なパターンで軸索内の区画に局在する．