Figure 4

Disturbed A-P somite polarity in Pofut1^cax/caxembryos. (A) WISH of E9.5 embryos with Notch targets. Hes1, Hey1 and HeyL expression is abnormal in the paraxial mesoderm of Pofut1^cax/caxembryos (b, f; n, r; z, zd) compared to wild type (a, e; m, q; y, zc), largely normal in other regions (compare j, v, zh with i, u, zg), and overall severely reduced in Pofut1^{tm1Pst/tm1Pst}embryos (d, h, l; p, t, x; zb, zf, zj). In Pofut1^cax/tm1Pstembryos expression in the paraxial mesoderm is more severely disrupted (c, g; o, s; za, ze), Hey1 and HeyL expression in the branchial bars reduced (w, zi) and Hes1 expression in the optic vesicle apparently unaffected (k). (B) WISH on E9.5 embryos detecting A-P somite polarity. Dll1, Tbx18 and Uncx4.1 show abnormal expression in Pofut1^cax/cax(b, f, j) and Pofut1^cax/tm1Pst(c, g, k) somites compared to wild type (a, e, i). Stripes are weaker (arrows in b), irregularly spaced (arrows in f and j) or blurred with stronger abnormalities in heteroallelic embryos (c, g, k). Pofut1^{tm1Pst/tm1Pst}embryos show increased expression of Dll1 (d) or Uncx4.1 (l) in the neural tube and no segment polarity (h, l). Instead of distinct stripes detected in wild type (m, q, u) Pofut1^cax/caxand Pofut1^cax/tm1Pstmutants exhibit blurry Cer1, Mesp2, and Papc expression (red lines in n, r, v, o, s, w). Pofut1^{tm1Pst/tm1Pst}embryos show weaker and fuzzy expression (p, t, x). Red lines indicate regions of fuzzy gene expression, arrows point to stripes of abnormal expression.