Probe:	hXBP-1 probe1
Probe preparation:	Antisense labelled with S35 RNA
Visualized with:	Autoradiography
Assay notes:	Specimens were embedded in paraffin or processed for cryosectioning; authors did not specify which. Authors report that 3 different antisense probes were used which resulted in similar intensity and patterns of hybridization.

Structure	Level	Pattern	Image	Note
TS19: pectoral-thoracic pre-cartilage condensation	Present	Regionally restricted	1A	First sites of specific tissue expression in developing clavicle and ribs at day 11.5.
TS19: skeleton	Present	Regionally restricted	1A	Expression higher in osteoblasts of clavicle than in cartilage of ribs.

Structure	Level	Pattern	Image	Note
TS20: skeleton	Present	Regionally restricted	1C	Expression at sites of intramembranous bone formation including frontal bone of calvaria, and maxillary and mandibular bones.
TS20: pectoral-thoracic pre-cartilage condensation	Present	Regionally restricted	1C	Expression in intramembranous bone of clavicle.
TS20: chondrocranium	Present	Regionally restricted	1C	Expression in intramembranous bone of calvaria.
TS20: jaw bone	Present	Regionally restricted	1C	Expression in intramembranous bone of mandible.

Structure	Level	Pattern	Image	Note
TS20: chondrocranium	Present	Regionally restricted	1D	In calvaria, expression in preosteoblasts and osteoblasts, particularly at sites where new bone is being actively deposited.

Structure	Level	Pattern	Image	Note
TS22: rib cartilage condensation	Strong	Regionally restricted	1E	Very high levels of expression in osteoblasts and preosteoblasts derived from osteoprogenitor cells of the periosteum forming the primary center of ossification of the outer bony outer periosteal cortex of cartilaginous ribs.

Structure	Level	Pattern	Image	Note
TS21: skeleton	Present	Regionally restricted	1F/G	Expression in an increasing number of sites of ossification, notably the bony diaphysis (bony periosteal cuff) of the midportion of long bones.
TS21: humerus cartilage condensation	Present	Regionally restricted	1F/G	Expression in preosteoblasts and osteoblasts of the newly forming diaphyses of the developing humerus. Lower expression in matrix secreting chondroblasts of the growth cartilage of the mature zone. Little if any expression in cartilage cells of hypertrophic zone.

Structure	Level	Pattern	Image	Note
TS24: upper jaw incisor	Present	Regionally restricted	1H	Significant levels of expression in osteoblasts and preosteoblasts of fine cancellous bone of maxilla corresponding to the zone of recently new bone. Expression much lower or absent in osteoblasts of older and more mature bone.

Structure	Level	Pattern	Image	Note
TS24: femur	Present	Regionally restricted	1I/J	Expression in mature zone of growth cartilage. Strong expression in periosteal preosteoblasts and osteoblasts actively forming new diaphyseal bone. Expression in cartilage limited principally to the matrix producing cells of mature zone of growth cartilage.
TS24: tibia	Present	Regionally restricted	1I/J	Expression in mature zone of growth cartilage. Strong expression in periosteal preosteoblasts and osteoblasts actively forming new diaphyseal bone. Expression in cartilage limited principally to the matrix producing cells of mature zone of growth cartilage.

Structure	Level	Pattern	Image	Note
TS26: femur	Present	Regionally restricted	1K/L	Expression in bony diaphysis formed by perichondral derived osteoblasts. Strong expression in osteoblasts and preosteoblasts in epiphyseal region just below resorbing degenerative zones of growth cartilage where osteoblasts are actively synthesizing new bone on calcified cartilage (endochondral ossification).
TS26: cartilage	Absent		1K/L	No expression in hypertrophic or degenerative cartilage cells.

Structure	Level	Pattern	Image	Note
TS22: lower jaw incisor dental papilla	Strong	Regionally restricted	2A/B	Expression first seen in lower jaw incisor, distributed uniformly over dental papilla. High levels of expression in dental papilla.
TS22: lower jaw alveolar sulcus	Strong	Regionally restricted	2A/B	High levels of expression in alveolar bone around Meckels cartilage.

Structure	Level	Pattern	Image	Note
TS24: upper jaw incisor	Strong	Regionally restricted	2C	High levels of expression in odontoblasts and in osteoblasts lining surfaces of newly synthesized fine cancellous intramembranous bone of maxilla. Expression in regions where precursor cells differentiate into active odontoblasts.
TS24: upper jaw incisor dental papilla	Weak		2C	Little expression in most dental papilla cells.

Structure	Level	Pattern	Image	Note
TS24: upper jaw incisor enamel organ	Present	Regionally restricted	2D	Expression also present in epithelial cell precursors of ameloblasts.

Structure	Level	Pattern	Image	Note
TS26: vibrissa follicle	Present	Regionally restricted	2E	Expression in an increasing number of whisker follicles.
TS26: vibrissa inner root sheath	Present	Regionally restricted	2E	Expression only in a restricted area of the inner root sheath.

Structure	Level	Pattern	Image	Note
TS22: rib cartilage condensation	Present	Regionally restricted	3D	Expression in osteoblasts of periosteal cuff of bone of rib cortex. Intense expression in derived from osteoprogenitor cells of the periosteum.

Structure	Level	Pattern	Image	Note
TS22: pancreatic acinus	Strong	Regionally restricted	4A	High levels of expression in acinar cells of pancreas. Maximum levels of expression in day 14.5 acini.

Structure	Level	Pattern	Image	Note
TS24: sublingual gland epithelium	Strong	Regionally restricted	4B	Highest levels of expression in the sublingual gland. Specific expression in epithelial (acinar) cells.
TS24: sublingual gland mesenchyme	Absent		4B
TS24: submandibular gland epithelium	Weak	Regionally restricted	4B	Lower levels of expression in acinar cells of submandibular gland.

Structure	Level	Pattern	Image	Note
TS24: salivary gland epithelium	Strong	Regionally restricted	4C	High levels of expression in minor salivary gland located below nasal cavity. Specific expression in epithelial (acinar) cells but not in the mesenchymal compartment.
TS24: salivary gland mesenchyme	Absent		4C
TS24: nasal cavity respiratory epithelium	Strong	Regionally restricted	4C	High levels of expression in secretory cells of the respiratory epithelium lining the nasal cavity.

Structure	Level	Pattern	Image	Note
TS24: nasal epithelium	Present	Regionally restricted	4D	Expression nasal glands and nasal epithelium.

Structure	Level	Pattern	Image	Note
TS26: brown fat	Present	Regionally restricted	5A	Expression at all sites of brown adipose tissue formation. Only certain areas were positive for expression. Expression in cells located at the extremities of the interscapular fat pad.

Structure	Level	Pattern	Image	Note
TS26: brown fat	Present	Regionally restricted	5B	Expression at all sites of brown adipose tissue formation. Expression in cells of interscapular brown adipose tissue. In the external region; only some cells were positive for expression.

Structure	Level	Pattern	Image	Note
TS17: embryo	Absent

Structure	Level	Pattern	Image	Note
TS19: pancreas primordium	Present			Data presented in Table 1.

Structure	Level	Pattern	Image	Note
TS20: pancreas	Present	Regionally restricted		Expression in acinar structures.

Structure	Level	Pattern	Image	Note
TS21: pancreatic acinus	Present

Structure	Level	Pattern	Image	Note
TS22: salivary gland	Present	Regionally restricted		Expression in minor salivary glands.
TS22: nasal cavity respiratory epithelium	Present	Regionally restricted		Expression in secretory cells.
TS22: vibrissa follicle	Weak	Regionally restricted		Data presented in Table 1.

Structure	Level	Pattern	Image	Note
TS24: pancreas	Present			Data presented in Table 1.
TS24: vibrissa follicle	Present	Regionally restricted		Expression in an increasing number of whisker follicles.
TS24: brown fat	Present			Data presented in Table 1.

Structure	Level	Pattern	Image	Note
TS26: pancreatic acinus	Weak
TS26: sublingual gland	Present			Data presented in Table 1.
TS26: submandibular gland	Present			Data presented in Table 1.
TS26: salivary gland	Present	Regionally restricted		Expression in minor salivary glands.
TS26: tooth	Weak			Data presented in Table 1.