Fig. 5. E12-13 (HH38-39) gonads infected with RCAS-Pitx2a virus in ovo at HH8-10 analysed for the expression of H2AX, ER plus LHX9, and Pitx2. (A) E12 uninfected wild-type and (B,C,D) three infected samples showing some degree of right gonad `puffiness'. Of the panels showing antibody staining for H2AX and for ER plus LHX9, in B the right gonad is indistinguishable from the left, whereas in C and D localised superficial areas of the right gonad contain clusters of meiotic germ cells and these areas are positive for epithelial ER. In the panels showing in situ hybridisation for Pitx2, expression is in the entire epithelium (B) or in localised areas (C,D) of right gonads. Co-localisation of Pitx2 and the left epithelial markers is evident. Arrowheads in C,D indicate left-like areas. L, left gonad; R, right gonad. Scale bars: white, 100 µm; black, 1 mm.