Probe:	Hoxa1 probe7
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present	Regionally restricted	2A	Anterior boundary at the presumptive r3/r4 border.
TS11: neural ectoderm	Present	Regionally restricted	2A	Anterior boundary at the presumptive r3/r4 border.

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present	Regionally restricted	2B	Expression extends from the posterior end of the embryo towards the node region, without reaching the normal anterior boundary. Expression levels were lower in mutants than in wild-type.
TS11: neural ectoderm	Present	Regionally restricted	2B	Expression extends from the posterior end of the embryo towards the node region, without reaching the normal anterior boundary. Expression levels were lower in mutants than in wild-type.

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present	Regionally restricted	2C	Anterior boundary at the presumptive r3/r4 border.
TS11: neural ectoderm	Present	Regionally restricted	2C	Anterior boundary at the presumptive r3/r4 border.

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present	Regionally restricted	2D	Expression domain in neurectoderm extends anteriorly to the node; the boundary was less defined and the level of expression was lower than in wild-type.
TS11: neural ectoderm	Present	Regionally restricted	2D	Expression domain in neurectoderm extends anteriorly to the node; the boundary was less defined and the level of expression was lower than in wild-type.

Structure	Level	Pattern	Image	Note
TS12: future hindbrain neural ectoderm	Present	Regionally restricted	2E	Anterior expression boundary at the presumptive r3/r4 junction; slightly higher in the presumptive r4-r6 region than posteriorly.
TS12: neural ectoderm	Present	Regionally restricted	2E	Anterior expression boundary at the presumptive r3/r4 junction; slightly higher in the presumptive r4-r6 region than posteriorly.
TS12: somite	Present		2E
TS12: trunk unsegmented mesenchyme	Present		2E

Structure	Level	Pattern	Image	Note
TS12: future hindbrain neural ectoderm	Present	Regionally restricted	2F	Anterior boundary roughly coincided with presumptive r3/r4 junction; less defined posterior boundary slightly rostral to axial level of first somite coinciding with presumptive r7. Posteriorly, substantial down-regulation in mutant neurectoderm.
TS12: neural ectoderm	Present	Regionally restricted	2F	Anterior boundary roughly coincided with presumptive r3/r4 junction; less defined posterior boundary slightly rostral to axial level of first somite coinciding with presumptive r7. Posteriorly, substantial down-regulation in mutant neurectoderm.
TS12: neural tube	Present		2F
TS12: somite	Present		2F	Expression was down-regulated in somitic and pre-somitic mesoderm as compared to wild-type.
TS12: trunk unsegmented mesenchyme	Present		2F	Expression was down-regulated in somitic and pre-somitic mesoderm as compared to wild-type.

Structure	Level	Pattern	Image	Note
TS13: future hindbrain	Absent			Expression domain progressively retreats caudally; in the neurectoderm, no longer detected in the hindbrain.
TS13: future spinal cord	Present			Expression domain progressively retreats caudally; expression only in the spinal cord.

Structure	Level	Pattern	Image	Note
TS13: future hindbrain	Absent
TS13: future spinal cord	Present			Mutant and wild-type embryos showed similar expression patterns; overall transcript levels were lower in the mutant.