Probe:	pOtd9
Probe preparation:	Antisense labelled with digoxigenin RNA

Structure	Level	Pattern	Image	Note
TS8: epiblast	Present		2A
TS8: extraembryonic component	Absent		2A

Structure	Level	Pattern	Image	Note
TS9: embryo	Present		2A
TS9: extraembryonic component	Absent		2A

Structure	Level	Pattern	Image	Note
TS10: embryo	Present	Regionally restricted	2B	Between the early- and late-streak stages, Otx2 expression became progressively restricted to the anterior half of the embryo.

Structure	Level	Pattern	Image	Note
TS11: embryo	Present	Regionally restricted	2C	Between the late-streak and headfold stages, expression became further restricted to the anteriormost third of the embryo.

Structure	Level	Pattern	Image	Note
TS11: embryo	Present	Regionally restricted	2C	Right-hand embryo in 2C.
TS11: future spinal cord neural plate	Present	Regionally restricted	2C	A sharp posterior boundary of expression was apparent in the neural plate.

Structure	Level	Pattern	Image	Note
TS12: future prosencephalon	Present		2D
TS12: future midbrain	Present		2D

Structure	Level	Pattern	Image	Note
TS13: future prosencephalon	Present		2D
TS13: future midbrain	Present		2D

Structure	Level	Pattern	Image	Note
TS8: epiblast	Present
TS8: extraembryonic component	Absent

Structure	Level	Pattern	Image	Note
TS10: embryo ectoderm	Present			Otx2 expression was present in all three germ layers at the anterior end of the embryo.
TS10: embryo endoderm	Present			Otx2 expression was present in all three germ layers at the anterior end of the embryo.
TS10: embryo mesoderm	Present			Otx2 expression was present in all three germ layers at the anterior end of the embryo.

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present		3C	Expression was present in all three germ layers at the anterior end.
TS11: embryo endoderm	Present		3C	Expression was present in all three germ layers at the anterior end.
TS11: embryo ectoderm	Present		3C	Expression was present in all three germ layers at the anterior end.

Structure	Level	Pattern	Image	Note
TS13: future midbrain	Present		3D
TS13: future prosencephalon	Present		3D
TS13: 1st branchial arch ectoderm	Weak		3D
TS13: foregut diverticulum	Weak		3D
TS13: head mesenchyme	Weak		3D
TS13: notochord	Weak		3D
TS13: optic eminence	Present		3D
TS13: 1st branchial pouch endoderm	Weak		3D

Structure	Level	Pattern	Image	Note
TS15: 1st branchial arch	Present		4A
TS15: future hindbrain	Absent		4A	The sharp posterior boundary of expression demarcates precisely the limit between midbrain and hindbrain regions.
TS15: future midbrain	Present		4A	The sharp posterior boundary of expression demarcates precisely the limit between midbrain and hindbrain regions.
TS15: trigeminal preganglion	Present		4A

Structure	Level	Pattern	Image	Note
TS15: 1st branchial arch	Present		4B
TS15: future hindbrain	Absent		4B	The sharp posterior boundary of expression demarcates precisely the limit between midbrain and hindbrain regions.
TS15: future midbrain	Present		4B	The sharp posterior boundary of expression demarcates precisely the limit between midbrain and hindbrain regions.
TS15: trigeminal preganglion	Present		4B