Probe:	HoxD1 probe
Probe preparation:	Antisense RNA

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	1A-1	Type 1 embryos (18 out of 129) showed a stronger stripe (S0) and a weak second band (S-I).
TS14: somite	Weak	Regionally restricted	1A-1	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	1A-2	Type 2 embryos (21 cases) were as type 1, but a more posterior band (S-I) with a broad and weak staining appeared.
TS14: somite	Present	Regionally restricted	1A-2	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	1A-3	In type 3 embryos (34 out of 129), the S-I stripe became predominant over that in S0, whereas the stripe in S1 was readily visible.
TS14: somite	Present	Regionally restricted	1A-3	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	1A-4	In type 4 embryos (39 cases), while the band in S0 declined in intensity, the signal in S-I became sharper due to the loss of expression in the posterior half of the previous domain.
TS14: somite	Weak	Regionally restricted	1A-4	Expressed in the newly condensed somite, visible only after prolonged staining.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1B-1	Type 1 embryos showed a stronger stripe (S0) and a weak second band (S-I).
TS15: somite	Weak	Regionally restricted	1B-1	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1B-2	Type 2 embryos were as type 1, but a more posterior band (S-I) with a broad and weak staining appeared.
TS15: somite	Present	Regionally restricted	1B-2	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1B-3	In type 3 embryos, the S-I stripe became predominant over that in S0, whereas the stripe in S1 was readily visible.
TS15: somite	Present	Regionally restricted	1B-3	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1B-4	In type 4 embryos, while the band in S0 declined in intensity, the signal in S-I became sharper due to the loss of expression in the posterior half of the previous domain.
TS15: somite	Weak	Regionally restricted	1B-4	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1B-5	Another type 4 embryo to illustrate the appearance of the somite boundary.
TS15: somite	Weak	Regionally restricted	1B-5	Expressed in the newly condensed somite.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1C lefy	In type 3 embryos, the S-I stripe became predominant over that in S0, whereas the stripe in S1 was readily visible.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1D	Type 1 embryos showed a stronger stripe (S0) and a weak second band (S-I).

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1E-1	Expressed in the first presumptive somite (S0 region).

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1E-2	Expressed in the first presumptive somite (S0 region). Mesp2 staining was detectable posterior to the Hoxd1 band in S0.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Strong	Regionally restricted	1E-3	Expressed in the first presumptive somite (S0 region), and colocalized with Mesp2 in a weak incipient, more posterior S-I band.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1E-4	Expressed in the first presumptive somite (S0 region), and colocalized with Mesp2 in a weak incipient, more posterior S-I band.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Strong	Regionally restricted	1F-1	Overlapped with Mesp2 expression by a broad and strong posterior band in S-I.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1F-2	Overlapped with Mesp2 expression by a narrower band in the anterior half of S-I.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1F-3	Overlapped with Mesp2 expression by a narrower band in the anterior half of S-I.

Structure	Level	Pattern	Image	Note
TS15: unsegmented mesenchyme	Present	Regionally restricted	1F-4	Expressed in the first presumptive somite (S0 region).

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2A-1 left	Type 2 embryos showed a stronger stripe (S0), a more posterior band (S-I) with a broad and weak staining appeared.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2A-2 left	Type 2 embryos showed a stronger stripe (S0), a more posterior band (S-I) with a broad and weak staining appeared.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2A-3 left	In type 3 embryos, the S-I stripe became predominant over that in S0, whereas the stripe in S1 was readily visible.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2B-1 left	Type 1 embryos showed a stronger stripe (S0) and a weak second band (S-I).

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2B-2 left	Type 2 embryos showed a stronger stripe (S0), a more posterior band (S-I) with a broad and weak staining appeared.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2B-3 left	In type 3 embryos, the S-I stripe became predominant over that in S0, whereas the stripe in S1 was readily visible.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2C-1 left	In type 3 embryos, the S-I stripe became predominant over that in S0, whereas the stripe in S1 was readily visible.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2C-2 left	In type 3 embryos, the S-I stripe became predominant over that in S0, whereas the stripe in S1 was readily visible.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	2C-3 left	In type 4 embryos, while the band in S0 declined in intensity, the signal in S-I became sharper due to the loss of expression in the posterior half of the previous domain.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	3A Hoxd1-1	In type 3 embryos, a broad band of expression in the entire S-I presumptive somite.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	3A Hoxd1-2	In type 3 embryos, a broad band of expression in the entire S-I presumptive somite.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	3A Hoxd1-3	In type 4 embryos, the signal in S-I became sharper and restriction to the rostral half, which was fully complementary to the expression of Lfng (localized to the posterior half).

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	3A Hoxd1-4	In type 4 embryos, the signal in S-I became sharper and restriction to the rostral half, which was fully complementary to the expression of Lfng (localized to the posterior half).

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	3A Hoxd1-5	Type 1 embryos showed a stronger stripe (S0) and a weak second band (S-I).

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	3B left	Coexpressed with Lfng in the S-I domain.

Structure	Level	Pattern	Image	Note
TS14: unsegmented mesenchyme	Present	Regionally restricted	3B right	As signal intensity of Lfng dropped in the posterior of the positive band, cells became single positive for Hoxd1.

Structure	Level	Pattern	Image	Note
TS12: somite	Absent		7A-1	Seven out of twelve mutant embryos showed no detectable transcripts.

Structure	Level	Pattern	Image	Note
TS12: somite	Weak		7A-2	Five out of twelve mutant embryos showed a reduced level of expression.
TS12: unsegmented mesenchyme	Present	Regionally restricted	7A-2	Expressed in a stripe of staining at the anterior edge of the presomitic region.

Structure	Level	Pattern	Image	Note
TS12: unsegmented mesenchyme	Present	Regionally restricted	7A-3	Expressed in a stripe of staining at the anterior edge of the presomitic region.
TS12: somite	Present		7A-3