Antibody:	anti-neurofilament (mouse)
Detection system:	Secondary antibody coupled to fluorescein

Structure	Level	Pattern	Image	Note
TS20: spinal cord	Present			In rostral sections, where the floor plate was present, expression was detected as in wild type. In caudal sections, where the floor plate was absent, aberrant expression was detected.

Structure	Level	Pattern	Image	Note
TS20: spinal cord	Present			In rostral sections, where the floor plate was present, expression was detected as in wild type. Extreme caudal sections showed little staining.

Structure	Level	Pattern	Image	Note
TS20: spinal ganglion	Present		1B
TS20: spinal cord	Present	Regionally restricted	1B	Expression was detected in the sensory routes projecting laterally from the alar plate and in the motor neuron columns in the lumbar spinal cord.

Structure	Level	Pattern	Image	Note
TS20: spinal cord	Present	Regionally restricted	1D	Expression was detected in the sensory routes, in the motor neuron columns and in a narrow region below the floor plate running between the two motor neuron columns in the caudal spinal cord.
TS20: spinal ganglion	Present		1D

Structure	Level	Pattern	Image	Note
TS20: spinal cord	Present	Regionally restricted	1F	Expression appeared broader at the ventral midline, the lumen was more circular with the neuroepithelium extending uniformly around the ventral midline.

Structure	Level	Pattern	Image	Note
TS21: spinal cord	Present			In rostral sections, at levels where the floor plate was present, expression in the heterozygote was the same as in wild-type embryos.

Structure	Level	Pattern	Image	Note
TS21: spinal cord	Present			Rostrally, at levels where the floor plate was present, expression in the mutant was the same as in wild-type embryos. Expression was aberrant in mutants in the absence of the floor plate. Expression varied depending on the distance from the floor plate.

Structure	Level	Pattern	Image	Note
TS21: spinal cord marginal layer	Present	Regionally restricted	2B	Rostral to the region lacking the floor plate, expression was broader in the marginal zone, reflecting the increase in number of neurons and their projecting axons.

Structure	Level	Pattern	Image	Note
TS21: spinal ganglion	Present		2D
TS21: spinal cord	Present	Regionally restricted	2D	Expression was detected in the sensory routes projecting laterally from the dorsal alar plate, in the motor neuron columns and in a narrow region below the floor plate running between the two motor neuron columns in the caudal spinal cord.

Structure	Level	Pattern	Image	Note
TS21: spinal cord	Weak	Regionally restricted	2F	Expression was weak in the most extreme caudal sections.

Structure	Level	Pattern	Image	Note
TS21: spinal cord	Weak	Regionally restricted	2H	Expression was weak in the most extreme caudal sections.