Untitled Document

NB 2-2 generates motoneurons innervating muscles 21,22,23 and intersegmental and local interneurons. At stage 15, motoneurons still have growth cones at their tips and axons of intersegmental interneurons are not yet extended beyond segmental boundaries.
NB 2-2 clone at stage 15: This NB 2-2 clone nicely demonstrates a phenomenon we observed frequently, namely medially migrating spacer cells that appar to make intimate contact with the axons of lineally related cells as they navigate entry into the commissures. They are the two dorsal most cells of this clone and the commissural axons are seen to "slide" into the space between them prior to entering the commissure. The cells of the NB 2-2 clone are uniformly round and large; the dendritic arborizations of the motoneurons in the ipsilateral longitudinal connectives are already in place by stage 16. upper left panel is a confocal z-series of DiI labeled clone; sections are 1.5 microns.The movie begins at the dorsal surface of the clone upper right panel is a projection of z-series, rotated 45 degrees about y-axis. DiI alone lower left panel is a confocal z-series of DiI-labeled clone in en-GFP background. lower right panel is a projection of the z-series, rotated 45 degrees about y-axis. DiI with en-GFP. In all cases, anterior is up.

NB 2-2 generates motoneurons innervating muscles 21,22,23 and intersegmental and local interneurons.

At stage 15, motoneurons still have growth cones at their tips and axons of intersegmental interneurons are not yet extended beyond segmental boundaries.

NB 2-2 clone at stage 15:

This NB 2-2 clone nicely demonstrates a phenomenon we observed frequently, namely medially migrating spacer cells that appar to make intimate contact with the axons of lineally related cells as they navigate entry into the commissures. They are the two dorsal most cells of this clone and the commissural axons are seen to "slide" into the space between them prior to entering the commissure. The cells of the NB 2-2 clone are uniformly round and large; the dendritic arborizations of the motoneurons in the ipsilateral longitudinal connectives are already in place by stage 16.

upper left panel is a confocal z-series of DiI labeled clone; sections are 1.5 microns.The movie begins at the dorsal surface of the clone

upper right panel is a projection of z-series, rotated 45 degrees about y-axis. DiI alone

lower left panel is a confocal z-series of DiI-labeled clone in en-GFP background.

lower right panel is a projection of the z-series, rotated 45 degrees about y-axis. DiI with en-GFP.

In all cases, anterior is up.