Figure 1. Positional mapping of the disconnected (disc) allele and forebrain overgrowth in homozygous mutants.

(a) The diagram shows the genomic interval on chromosome 5 between markers D5Mit156 and D5Mit275 to which the disc mutation was mapped. All protein-encoding genes within the interval of which all exons were sequenced for this study are shown. (b) Sequence chromatograms of wild-type and disc/disc PCR amplicons show the position of the only identified coding variant (T to A, nonsense). (c) The schematic shows the recognized domains of mouse Wdfy3 protein with the causative stop codon of the disc allele at position 3046 indicated. The first residue of each domain is given in the diagram. (d) Dorsal views of whole-mount brains show morphological anomalies in the homozygous disc mutants where indicated by the asterisk. (e) Nissl-stained coronal hemisections through the forebrains of E15.5 WT and homozygous disc mutants illustrate the malformations present in affected mutants. The green lines delineate the measurements taken for cortical length and thickness (D, dorsal; ML, mediolateral; L, lateral), while the orange area indicates how cortical size was measured. (f) Close-ups of the mediolateral cerebral cortex illustrate cortical thinning in disc/disc mutants. (g) Quantification of individual cortical spatial parameters confirm significant increases in length and overall size, but radial thinning in basolateral aspects. All analysis by Student’s t-test, n for either genotype is indicated in the bar diagrams, which present mean and standard error of the mean (SEM). Asterisks mark significant changes with calculated p-values shown. ATN, anterior thalamic nuclei; Cb, cerebellum; CP, cortical plate; Cx, cerebral cortex; HC, hippocampus; IZ, intermediate zone; LGE, lateral ganglionic eminence; LV, lateral ventricles; MZ, marginal zone; SM, stria medullaris; SVZ, subventricular zone; Th, thalamus; VZ, ventricular zone. Scale bar in e is 500 μm and in f 100 μm.