Survey of embryonic expression. (A) Whole mouse embryo [poly(A) RNA; CLONTECH] blot. Lanes: 1b, e7; 2, e11; 3, e15; 4, e17. Lane 1a is a dark exposure of lane 1b, more clearly demonstrating the presence of a 2.3-kb transcript. (B) In situ hybridization in e14.5 embryo with predominant expression in: 1, brain; 2, thymus; 3, lung; 4, liver; and 5, kidney. (C) In situ hybridization in e9.5 mouse embryo showing high levels of expression in: 1, neuroepithelium; 2, mandibular arch; 3, gut primordium; 4, liver primordium; and 5, intermediate mesoderm. Sense probes gave no detectable signal (data not shown).