Probe:	ESP probe 1
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase
Assay notes:	Authors state that two probes, ESP probe1 (MGI:5498011) and ESP probe2 (MGI:5498012) were used for whole mount in situ hybridization in this study.

Structure	Level	Pattern	Image	Note
TS8: epiblast	Present	Uniform	5A
TS8: extraembryonic ectoderm	Absent		5A
TS8: primitive endoderm	Absent		5A

Structure	Level	Pattern	Image	Note
TS10: embryo mesoderm	Present	Regionally restricted	5B	Expression in nascent embryonic mesoderm emerging from primitive streak and anteriorly as two bands of mesoderm on either side of notochord. No expression in notochord
TS10: node	Absent		5B

Structure	Level	Pattern	Image	Note
TS11: primitive streak	Present		5C
TS11: embryo mesoderm	Present	Regionally restricted	5C	Expression in mesoderm in two continuous wide bands in anterior of embryo (under head folds) on either side of midline (neural groove). No expression in narrow strip extending from neural groove to node.
TS11: node	Absent		5C
TS11: notochordal plate	Absent		5C

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present	Regionally restricted	5D	Expression in streak and in two broad bands under head folds on either side of neural groove. No expression in narrow strip extending from neural groove to node.
TS11: node	Absent		5D
TS11: notochordal plate	Absent		5D

Structure	Level	Pattern	Image	Note
TS13: embryo mesenchyme	Weak	Regionally restricted	5E	Authors state that expression was down-regulated in non-notochordal mesoderm.

Structure	Level	Pattern	Image	Note
TS10: embryo mesoderm	Present		6A
TS10: embryo ectoderm	Absent		6A
TS10: embryo endoderm	Absent		6A

Structure	Level	Pattern	Image	Note
TS11: embryo mesoderm	Present	Regionally restricted	6B	Expression in non-axial mesoderm.
TS11: head mesenchyme	Strong	Regionally restricted	6B	Highest levels of expression in cranial mesoderm underlying developing forebrain and future midbrain neurectoderm.