Stained and pseudo colored images of in situ hybridization for Sox9, Col2a1, and Runx2 on transverse sections from the mandibular processes of control (Prx1+/-;Prx2-/-) (A-L) and Prx1;Prx2 double mutant (M-X) embryos at E12.5.
(A-D) are adjacent transverse sections through the caudal region of the mandibular processes from a control embryo showing that Sox9 and Col2a1 are expressed in the Meckel’s cartilage. Runx2 is not expressed in the Meckel’s cartilage (indicated by black circle) and is expressed in the mandibular bones.
(E-H) are adjacent transverse sections through the middle region of the mandibular processes from a control embryo showing that Sox9 and Col2a1 are expressed in the Meckel’s cartilage. Runx2 is not expressed in the Meckel’s cartilage but is expressed in the developing bone adjacent to Meckel’s’ cartilage (H).
(I-L) are adjacent transverse sections through the rostral region of the mandibular processes from a control embryo showing the Sox9 and Col2a1 are expressed in the Meckel’s cartilage in the rostral tip. Runx2 is not expressed in the rostral region.
(M-P) are adjacent transverse sections through the caudal region of the mandibular processes from a Prx1;Prx2 double mutant embryo showing the expression of Sox9 and Col2a1 in the Meckel’s cartilage. Runx2 is not expressed in the Meckel’s cartilage but is expressed at slightly higher levels and in a larger domain as compared to control (D).
(Q-T) are adjacent transverse sections through the middle region of the mandibular processes from a Prx1;Prx2 double mutant embryo and lack of expression Sox9 and Col2a1 in the medial region of the mandibular processes. Note the robust expression of Runx2 in mandibular processes of the Prx1;Prx2 double mutant embryo as compared to control (H).
(U-X) are adjacent cross sections through the rostral region of the mandibular processes from a Prx1;Prx2 double mutant embryo showing reduced domains and levels of expression of Sox9 and Col2a1 as compared to controls (J, K). Note the high levels of Runx2 in mandibular processes of the Prx1;Prx2 double mutant embryo as compared to control (L). Abbreviations: mc, Meckel’s cartilage; ns, nasal septum; asterisk, tongue. Scale bars =100 um.