Probe:	Sek-4 cDNA1
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS11: embryo	Present	Regionally restricted	4A	Expression was detected in the anterior half of the embryo.

Structure	Level	Pattern	Image	Note
TS11: embryo	Present	Regionally restricted	4B	Expression was detected in the anterior half of the embryo.
TS11: embryo mesoderm	Present	Regionally restricted	4B	Expression was detected in the anterior mesoderm.
TS11: neural ectoderm	Present		4B

Structure	Level	Pattern	Image	Note
TS12: neural ectoderm	Present	Regionally restricted	4C	Expression was detected in the anterior half of the neuroectoderm.
TS12: embryo	Present	Regionally restricted	4C	Expression was detected in the posterior tip of the embryo.
TS12: head mesenchyme	Present		4C	Expression was detected in the mesoderm of the headfold.

Structure	Level	Pattern	Image	Note
TS12: rhombomere	Present	Regionally restricted	4D	Expression was detected in the area of rhombomere 2 and 3. The expression was at a low level and the boundaries were not well defined.
TS12: future midbrain	Present	Regionally restricted	4D	Expression was detected in the ventral midbrain.
TS12: future prosencephalon	Present	Regionally restricted	4D	Expression was detected in the ventroposterior forebrain.

Structure	Level	Pattern	Image	Note
TS13: future midbrain	Present		4E
TS13: future prosencephalon	Present		4E
TS13: rhombomere 3	Present		4E
TS13: rhombomere 5	Present		4E

Structure	Level	Pattern	Image	Note
TS13: rhombomere 3	Present		4F
TS13: rhombomere 5	Present		4F
TS13: future midbrain	Weak		4F
TS13: future prosencephalon	Weak		4F

Structure	Level	Pattern	Image	Note
TS13: head mesenchyme	Weak		5A
TS13: somite	Present	Regionally restricted	5A	Expression was detected in somites. More recently formed somites have a higher level of expression.
TS13: foregut diverticulum	Present		5A

Structure	Level	Pattern	Image	Note
TS14: head mesenchyme	Weak		5C
TS14: somite	Present	Regionally restricted	5C	Expression was detected in somites. More recently formed somites have a higher level of expression.
TS14: foregut	Present		5C
TS14: rhombomere 5	Present		5C

Structure	Level	Pattern	Image	Note
TS14: rhombomere 5	Trace		5D
TS14: otic pit	Present	Regionally restricted	5D	Expression was transiently detected in the otic vesicle at the 20-25 somite stage.

Structure	Level	Pattern	Image	Note
TS15: head mesenchyme	Present	Regionally restricted	5G	Expression was detected in mesenchyme in the facial region.
TS15: 1st branchial arch	Present	Non-Uniform	5G	Expression was most intense in the anterior half of the first branchial arch.
TS15: 2nd branchial arch	Present		5G
TS15: trunk mesenchyme	Present	Regionally restricted	5G	Expression was detected in the lateral mesoderm at the level of the forelimb bud.