Fig. 6. Rescue of Zic2-depletion by injection of CerS. (A) Analysis of microcephaly (microceph.) and axial truncations (axial trunc.) in control stage 33 embryos (Un), controls injected with 50 pg CerS mRNA (Un+CerS), Zic2-depleted embryos (Zic2-) or Zic2-embryos injected with 50 pg CerS mRNA (Zic2-, +CerS). Data were pooled from two host-transfer experiments. Bars represent the number of embryos with the indicated phenotype. Axial truncations were present in a subset of embryos with microcephaly. (B) Expression of Xnr1, Xnr5 and Xnr6 in gastrula (stage 10.5) stage embryos analyzed by RT-PCR. (C,C') Examples of embryos from the experiment in B. Zic2-embryos show both microcephaly and axial truncation; the Zic2-, +CerS embryos represent a normal and a microcephalic embryo (upper and lower embryo, respectively).