Fig. 2

The morphological phenotype of CASK mutants involves head, brain, and body. a Photomicrographs of Drosophila pharate adults, anterior at the top. Left, Canton-S wildtype within the puparium (also called "pupal case"), dorsal view. Vertical dotted line represents body length. Arrows show the centers of the head, thorax, and abdomen (top to bottom, respectively). Asterisk marks the air space anterior to the animal. Center and right, dorsal and ventral views, respectively, of a female genetic control, dissected from the puparium but still wrapped by the transparent pupal cuticle. Adapted from [41], with permission. b Photomicrograph of a histological section through the head of a CASK-control (Ex13/Ex13) pharate adult, frontal plane. Scale bar as indicated. Colorized and thickened dashed outlines overlay the perimeters of the CNS (yellow) and head (dark blue), traced using cellSens software. e, esophagus; M, muscles; OL, optic lobe; P, proboscis; R, retina; SEZ, subesophageal zone; SPZ, supraesophageal zone. (c-j) Abnormal morphology of CASK Δ18/Δ18 mutants compared with Ex33/Ex13 controls. Each circle represents a single fly; color legend shown to the right of panel f. Horizontal black lines are medians. Significance levels: *, p < 0.05; **, p < 0.005; ***, p < 0.0005. In CASK mutants, c estimated brain volume was reduced (p = 0.0002); d estimated head volume was reduced (p = 0.0007); e the percentage of head volume occupied by the brain was increased (p = 0.0288); f scatter plot of head volume vs. brain volume shows a positive linear relationship in both mutants and controls; (g) body length was reduced (p < 0.0001); h-i scatter plots of body length vs. brain volume or head volume show distinct distributions of mutant and control data and no strong indication of linear relationships; j in a 3D scatter plot of brain volume, head volume, and body length, the data from the two genotypes are nonoverlapping, which was confirmed by rotating the graph