Independence of concentric periodic patterning from germ band formation and elongation. A: A spontaneous abnormal embryo showing primary concentric periodic patterning of the gene eve1, but not germ band formation. The same embryo is viewed laterally (A1 and A2) and orthogonally to that view from the proctodeum (asterisk) (A3 and A4) (A1 and A3 same view, respectively, as A2 and A4, but under fluorescent light (SYBR green nuclear staining). B-C: A normal germ band (B) and an abnormally shorter one (C) with the same number of morphologically formed LBS (18), stained for Delta, flat mounted and aligned (magenta dotted line marking the stomodeum). In the short embryo, the number of rings of delta expression that have resolved is similar to that in the normal embryo at the same stage, but the spacing of these rings is very different. False colored Delta staining has been overlayed on the germ band viewed in fluorescent light to show the morphology (DAPI nuclear staining). Note that in C the artificial overlap has been done only for the posterior segmental patterning). Anterior Delta stain shows as dark dots. Asterisk marks the proctodeum. Scale bar in A: 400 μm; in B and C: 100 μm.