Figure 4. Prx1-LPM lineage contribution to neck and pectoral girdle.
See also Figure 4—figure supplement 1, 2. (A–D) X-gal stainings of Prx1Cre;R26R reporter mice at E9.5 (n = 3) (A) and E18.5 (n = 3) (C–D), and immunostaining for GFP and the Pax7/Myod/My32 myogenic markers in Prx1Cre;R26mTmG E12.5 embryo (n = 2) (B). Note Prx1-derived cells in postcranial LPM (A, black arrowheads) and Prx1-derived cells among, but not in, cucullaris myofibres (B–D). (E–F’’) Immunostaining for β-gal, Tnnt3 and Tcf4 on coronal cryosections of E18.5 Prx1Cre;R26R mice (n = 2) showed β-gal+ cells constituting the pectoral girdle (E, level C in Figure 1) and in MCT fibroblasts (F-F’’, white arrowheads), but not in trapezius myofibres. acp, scapular acromion process; atp, acromiotrapezius; ccl, cucullaris anlage; ccp, scapular coracoid process; cl, clavicle; epm, epaxial musculature; hh, humeral head; lb, forelimb bud; lbm, limb muscle anlagen; LPM, lateral plate mesoderm; ltd, latissimus dorsi; PA1-6, pharyngeal arches 1–6; S3, somite 3; scp, scapular muscles; stm, sternocleidomastoid; stp, spinotrapezius. Scale bars: in A for A, B 500 µm; in C for C-D 2000 µm, for E 500 µm; in F’’ for F-F’’ 20 µm.