Antibody:	Anti-Annexin IV
Detection system:	Biotinylated secondary antibody/[Strept]avidin coupled to horseradish peroxidase
Assay notes:	The fixative for normal and Danforth's short-tail embryos was acetic acid:ethanol (1:3). The fixative for curly-tail embryos was paraformaldehyde-lysine-periodate (PLP).

Structure	Level	Pattern	Image	Note
TS11: notochordal plate	Absent			Expression was absent from the notochord.
TS11: notochordal process	Absent			Expression was absent from the notochord.
TS11: neural ectoderm	Absent			Expression was absent from the central nervous system.

Structure	Level	Pattern	Image	Note
TS12: notochord	Absent
TS12: neural ectoderm	Absent			Expression was absent from the central nervous system.

Structure	Level	Pattern	Image	Note
TS13: notochord	Present		1A
TS13: notochordal plate	Present		1A
TS13: neural tube floor plate	Absent		1A

Structure	Level	Pattern	Image	Note
TS15: notochord	Strong		1B
TS15: neural tube floor plate	Weak	Regionally restricted	1B	Expression was detected in a row of cells just ventral to the lumen of the neural tube and in radial processes running from the region of these cells to the pial surface.

Structure	Level	Pattern	Image	Note
TS17: notochord	Present		1C
TS17: neural tube floor plate	Present	Regionally restricted	1C	Expression was detected in transversely oriented fibers restricted to the lower third of the floor plate region.

Structure	Level	Pattern	Image	Note
TS23: embryo mesenchyme	Present		1D	Expression was detected in the notochord.

Structure	Level	Pattern	Image	Note
TS17: neural tube floor plate	Present	Regionally restricted	2A	Expression was detected in a small region of lightly labeled transverse fibers in the floor plate region subjacent to the pia.

Structure	Level	Pattern	Image	Note
TS21: spinal cord floor plate	Present	Regionally restricted	2B	Expression was detected in a broader band of radially oriented cells and fibers and was strong in a region of transversely oriented fibers.

Structure	Level	Pattern	Image	Note
TS17: neural tube roof plate	Present	Single cells	3A

Structure	Level	Pattern	Image	Note
TS20: spinal cord roof plate	Present	Regionally restricted	3B	Expression was detected in a wedge-shaped region just dorsal to the central canal.

Structure	Level	Pattern	Image	Note
TS23: spinal cord roof plate	Present	Regionally restricted	3C	Expression was detected in a thin septum of cells straddling the midline.

Structure	Level	Pattern	Image	Note
TS20: blood vessel	Present		4A
TS20: spinal cord roof plate	Present		4A
TS20: spinal cord floor plate	Absent		4A	In the lumbar region of the spinal cord, expression is absent from the floor plate region (the mutant lacks a floor plate in caudal spinal cord).
TS20: basal columns	Absent		4A	In the lumbar region of the spinal cord, expression is absent from the ventral motor neurons.

Structure	Level	Pattern	Image	Note
TS20: spinal cord roof plate	Present		4B
TS20: spinal cord floor plate	Weak	Regionally restricted	4B	In the lower thoracic region of the spinal cord, expression is sparse with only a few positive fibers.
TS20: basal columns	Weak		4B

Structure	Level	Pattern	Image	Note
TS20: spinal cord roof plate	Present		4C
TS20: spinal cord floor plate	Present		4C	In the rostral thoracic region spinal cord, expression in the floor plate of the mutant is similar in location and level to wild type.
TS20: basal columns	Present		4C	In the rostral thoracic region spinal cord, expression in the ventral motor neurons of the mutant is similar in location and level to wild type.

Structure	Level	Pattern	Image	Note
TS21: spinal cord roof plate	Present		5A	In rostral spinal cord, expression was detected in the roof plate as in wild type.

Structure	Level	Pattern	Image	Note
TS21: spinal cord roof plate	Absent		5B	In an abnormal region of the neural tube, where edges of the neural tube were still in contact or were closely apposed, no expression was detected in presumptive roof plate cells, expected to be located at the lateral margins of the open neural tube.
TS21: spinal cord floor plate	Present		5B	Expression was similar to controls.
TS21: basal columns	Present	Regionally restricted	5B	Expression in ventral motor neurons was similar to controls.

Structure	Level	Pattern	Image	Note
TS21: spinal cord roof plate	Absent		5C	In an abnormal region of the neural tube, where the neural tube was open, no expression was detected in presumptive roof plate cells, expected to be located at the lateral margins of the open neural tube.
TS21: spinal cord floor plate	Present		5D , 5C
TS21: basal columns	Present		5C , 5D	Expression was detected in ventral motor neurons.
TS21: dorsal root ganglion	Present		5C , 5E

Structure	Level	Pattern	Image	Note
TS20: spinal cord floor plate	Present		6A	Expression in the floor plate extends throughout the spinal cord including the most caudal portion.
TS20: notochord	Present		6A

Structure	Level	Pattern	Image	Note
TS20: medulla oblongata floor plate	Present		6B
TS20: metencephalon floor plate	Present		6B
TS20: midbrain floor plate	Weak		6B
TS20: diencephalon floor plate	Present		6C , 6B	Expression was detected in the diencephalon and lamina terminalis, but the region between the diencephalon and the lamina terminalis, the mammillary region, had light, punctate staining.
TS20: diencephalon lamina terminalis	Present		6C , 6B	Expression was detected in the diencephalon and lamina terminalis, but the region between the diencephalon and the lamina terminalis, the mammillary region, had light, punctate staining.