Probe:	Irxl1 cDNA1
Probe preparation:	Antisense labelled with P33 RNA
Assay notes:	The authors did not specify which probe was used, they could have used Irxl1 cDNA2 (MGI:3639501). They state that both probes detected identical expression patterns during mouse embryogenesis in both whole mount and section in situ hybridization assays.

Structure	Level	Pattern	Image	Note
TS15: trunk dermomyotome	Present		2G	Expression is in the dermamyotome of differentiating rostral somites.

Structure	Level	Pattern	Image	Note
TS17: trunk dermomyotome	Present		2H
TS17: fronto-nasal process	Moderate		2H
TS17: head mesenchyme derived from neural crest	Moderate		2H
TS17: yolk sac	Weak		2H

Structure	Level	Pattern	Image	Note
TS19: frontal process mesenchyme	Strong		2I
TS19: head mesenchyme derived from neural crest	Strong		2I
TS19: medial-nasal process	Strong		2I
TS19: head mesenchyme	Strong	Regionally restricted	2I	Expression is surrounding the otic vesicle and in a region ventral to the telencephalic vesicles.

Structure	Level	Pattern	Image	Note
TS19: trunk dermomyotome	Present	Regionally restricted	2J	Expresssion is in the dorsal and ventral domains in the dermomyotomes between the fore- and hind-limb buds.
TS19: frontal process mesenchyme	Strong		2J
TS19: head mesenchyme derived from neural crest	Strong		2J
TS19: medial-nasal process	Strong		2J
TS19: head mesenchyme	Strong		2J	Expression is surrounding the otic vesicle.

Structure	Level	Pattern	Image	Note
TS19: limb	Strong	Regionally restricted	2K	Expression is in myogenic precursor cells migrating into the limb buds.
TS19: trunk mesenchyme	Strong	Regionally restricted	2K	Expression is in myogenic precursor cells migrating into the limb buds.
TS19: latero-nasal process	Present		2K
TS19: medial-nasal process	Present		2K

Structure	Level	Pattern	Image	Note
TS20: palatal shelf mesenchyme	Strong		3A
TS20: head mesenchyme	Strong	Regionally restricted	3A	Expression is in neural crest-derived head mesenchyme surrounding the brain.
TS20: mandible primordium	Strong	Regionally restricted	3A	Expresion is in the preossification mesenchymal cells.
TS20: skeletal muscle	Strong	Regionally restricted	3A	Expression is in a subset of craniofacial and body skeletal muscle.

Structure	Level	Pattern	Image	Note
TS21: palatal shelf mesenchyme	Strong		3B
TS21: head mesenchyme	Strong	Regionally restricted	3B	Expression is in neural crest-derived head mesenchyme surrounding the brain.
TS21: mandible mesenchyme	Strong	Regionally restricted	3B	Expresion is in the preossification mesenchymal cells.
TS21: skeletal muscle	Strong	Regionally restricted	3B	Expression is in a subset of craniofacial and body skeletal muscle.
TS21: tongue muscle	Strong	Regionally restricted	3B

Structure	Level	Pattern	Image	Note
TS22: palatal shelf mesenchyme	Strong		3C
TS22: head mesenchyme	Strong	Regionally restricted	3C	Expression is in neural crest-derived head mesenchyme surrounding the brain.
TS22: mandible	Strong	Regionally restricted	3C	Expresion is in the preossification mesenchymal cells.
TS22: skeletal muscle	Strong	Regionally restricted	3C	Expression is in a subset of craniofacial and body skeletal muscle.
TS22: tongue muscle	Strong	Regionally restricted	3C

Structure	Level	Pattern	Image	Note
TS22: skeletal muscle	Strong	Regionally restricted	3D	Expression is in a subset of craniofacial and body skeletal muscle. Some muscle bundles only express mRNA in terminal regions.
TS22: tongue muscle	Strong	Regionally restricted	3D

Structure	Level	Pattern	Image	Note
TS22: skeletal muscle	Strong	Regionally restricted	3E	Expression is in a subset of craniofacial and body skeletal muscle.
TS22: cervical intervertebral disc	Strong		3E
TS22: tail mesenchyme	Present	Regionally restricted	3E	Expression is in the tail muscles.
TS22: cervical vertebral cartilage condensation	Absent		3E
TS22: liver	Absent		3E