Probe:	Tbx20 probe
Probe preparation:	Antisense labelled with digoxigenin RNA
Visualized with:	Alkaline phosphatase

Structure	Level	Pattern	Image	Note
TS10: allantois	Present		3A
TS10: amniotic fold mesoderm	Present		3A

Structure	Level	Pattern	Image	Note
TS11: allantois mesoderm	Present		3B
TS11: amnion mesoderm	Present		3B
TS11: cardiogenic plate	Present		3B
TS11: chorion mesoderm	Present		3B

Structure	Level	Pattern	Image	Note
TS12: cardiogenic plate	Present		3C
TS12: exocoelomic cavity	Present		3C
TS12: extraembryonic mesenchyme	Present		3C
TS12: lateral plate mesoderm	Present		3C
TS12: primitive heart tube	Present		3C

Structure	Level	Pattern	Image	Note
TS13: heart	Strong		3D
TS13: lateral plate mesoderm	Strong		3D
TS13: extraembryonic component	Strong	Regionally restricted	3D	Expression is in the allantois.

Structure	Level	Pattern	Image	Note
TS13: heart	Strong		3E
TS13: lateral plate mesoderm	Strong		3E
TS13: extraembryonic component	Strong	Regionally restricted	3E	Expression is in the allantois.

Structure	Level	Pattern	Image	Note
TS15: optic vesicle	Present	Regionally restricted	3F	Expression is dorsal.
TS15: heart	Present		3F
TS15: rhombomere 2	Present		3F
TS15: rhombomere 4	Present		3F
TS15: trunk mesenchyme	Present	Regionally restricted	3F	Expression is in lateral plate mesenchyme.
TS15: extraembryonic component	Present	Regionally restricted	3F	Expression is in the allantois.

Structure	Level	Pattern	Image	Note
TS17: heart	Present		3G
TS17: optic cup	Present		3G
TS17: neural tube	Present	Graded	3G	Expression is ventral and strongest in rhombomere 4.
TS17: extraembryonic component	Present	Regionally restricted	3G	Expression is in the allantois.
TS17: trunk mesenchyme	Present	Regionally restricted	3G	Expression is in lateral plate mesenchyme.

Structure	Level	Pattern	Image	Note
TS19: heart	Present		3H
TS19: neural retinal epithelium	Present		3H
TS19: neural tube basal columns	Present		3H
TS19: liver	Present	Regionally restricted	3H
TS19: urinary system	Present	Regionally restricted	3H
TS19: extraembryonic component	Present	Regionally restricted	3H	Expression is in the allantois.
TS19: trunk mesenchyme	Present	Regionally restricted	3H	Expression is in the lateral plate mesoderm.

Structure	Level	Pattern	Image	Note
TS20: heart left ventricle	Present		3I	Expression in the myocardium is much stronger than in the endocardium.
TS20: heart right ventricle	Present		3I	Expression in the myocardium is much stronger than in the endocardium.
TS20: left atrium	Present		3I	Expression in the myocardium is much stronger than in the endocardium.
TS20: right atrium	Present		3I	Expression in the myocardium is much stronger than in the endocardium.

Structure	Level	Pattern	Image	Note
TS14: rhombomere 2	Present	Regionally restricted	4A	Expression is in two columns of ventral cells.
TS14: rhombomere 4	Present	Regionally restricted	4A	Expression is in two columns of ventral cells.

Structure	Level	Pattern	Image	Note
TS15: rhombomere 2	Present	Regionally restricted	4B	Expression is in two ventral columns of neurons.
TS15: rhombomere 4	Present	Regionally restricted	4B	Expression is in two ventral columns of neurons.
TS15: rhombomere 7	Present	Regionally restricted	4B	Expression is in two ventral columns of neurons.
TS15: neural tube	Present	Regionally restricted	4B	Expression is in two ventral columns of the cervical spinal cord.

Structure	Level	Pattern	Image	Note
TS17: rhombomere 2	Strong	Regionally restricted	4C	Expression is in two ventral longitudinal columns. In rhombomere 2, dorsally projecting axons also express.
TS17: rhombomere 4	Strong	Regionally restricted	4C	Expression is in two ventral longitudinal columns. In rhombomere 2, dorsally projecting axons also express.
TS17: neural tube	Present	Regionally restricted	4C	Expression is in two ventral longitudinal stripes.
TS17: rhombomere 3	Present	Regionally restricted	4C	Expression is in two ventral longitudinal stripes.
TS17: rhombomere 5	Present	Regionally restricted	4C	Expression is in two ventral longitudinal stripes.
TS17: rhombomere 6	Present	Regionally restricted	4C	Expression is in two ventral longitudinal stripes.
TS17: rhombomere 7	Present	Regionally restricted	4C	Expression is in two ventral longitudinal stripes.

Structure	Level	Pattern	Image	Note
TS19: hindbrain	Present	Regionally restricted	4D	Expression is lost in the area corresponding to rhombomeres 3 and 7. In the area of rhombomere 2, expression is in the dorsal migrating axons. Staining is in motor neurons. Staining in rhombomeres 5 and 6 is from rhombomere 4 neurons migrating caudally.

Structure	Level	Pattern	Image	Note
TS17: neural tube lateral wall	Present	Single cells	4E	Expression is in postmitotic motor neurons in the ventral-lateral aspect of the mantle layer of the cervical spinal cord.

Structure	Level	Pattern	Image	Note
TS17: rhombomere 2 mantle layer	Present	Single cells	4F	Expression is in postmitotic motor neurons in the ventral-lateral aspect of the mantle layer.