Fig 1.
Ocular development in mice with retina-specific knockout of the Bmal1 gene (rBmal1 KO mice) compared to their littermate controls (Bmal1fl/fl mice).
A. The refractions of rBmal1 KO mice are shifted negatively, i.e., significantly more myopic, compared to the Bmal1fl/fl controls across all ages tested (P0 = 0.005). B. The absence of rBmal1 results in an elongated axial length of the eye (P0 = 0.015). C. While the vitreous cavity depths decrease during the experimental period in both genotypes, the vitreous cavity depths of the rBmal1 KO mice are consistently longer than those of the Bmal1fl/fl controls (P0<0.001). D. The anterior chambers of the rBmal1 KO mice deepened less than those of the Bmal1fl/fl controls at 6 weeks and remained shallower at subsequent times. (P0 = 0.009). E. A greater lens thickness of rBmal1 KO than Bmal1fl/fl controls developed by 6 weeks of age and increased with age (P0 = 0.024). F. Corneal curvatures are equivalent for rBmal1 KO mice compared to Bmal1fl/fl control mice (P0, n.s.). P0 specifies ANOVA assessments for either inter-genotype comparisons or the interaction of genotype by age; post-hoc comparisons for the genotype by age interactions: *p<0.05, **p<0.01, ***p<0.001. Data appear in S1, S2 and S3 Tables.
Fig 2.
Schematic illustration of principal anatomical alterations in the mouse eye, comparing the Bmal1fl/fl control mice to mice with retinal-specific knockout of the Bmal1 gene (rBmal1 KO).
Compared to their littermate Bmal1fl/fl controls, the rBmal1 KO mice develop shallower anterior chambers, thicker lenses, and longer vitreous chambers, resulting in overall longer axial lengths. Data appear in Fig 1 and in S1, S2 and S3 Tables.
Fig 3.
Circadian clock disruption and the morphology of the anterior part of Drosophila ommatidia.
A & B. Schematic drawings comparing the human eye and clinical myopia to the Drosophila ommatidium in flies without and with a clock gene knockout. The cornea-(anterior chamber)-lens complex of the human eye (A) corresponds to the facet lens of the Drosophila ommatidium (B); the human vitreous chamber, to the Drosophila pseudocone. These optical components focus incoming light on the human retina or on Drosophila retinula cells. Human myopia most commonly results from vitreous chamber elongation (A, left). Clock gene mutations result in lengthened pseudocones (B, right), paralleling the main abnormality in human myopia. Dashed red lines and arrows facilitate comparison of the normal to altered structures in both species. Magnification bars illustrate the marked scale differences between the imaging structures of these species. C. At 5 days of age, the pseudocone length is greater in flies with null mutations of the clock genes cycle or period (cyc01 or per01), relative to control wildtype (WT) flies. At 20 days, the pseudocone lengthening remained statistically significant for the cyc01 flies but became a trend for the per01 flies (p = 0.07). D. The facet lens diameters are not affected at 5 days; at 20 days, the facet lens in per01 but not cyc01 flies was modestly wider than in WT flies. E. Facet lens thicknesses were unaffected at either age. F. The radius of curvature of the facet lens was longer in mutants compared to WT flies at 5 days; by post hoc testing, this lengthening reached statistical significance for the cyc01 flies. By 20 days, the curvature effect was no longer evident. For each cohort, the numbers of flies and ommatidium regions measured appear in S4 and S5 Tables. Box plots: solid squares, means; rectangular area, 25ā75 percentiles; fences, 1.5X (interquartile range); open circles, outliers. P0, p-values of the overall statistical effect for each group. Bars, within-age statistically significant comparisons by post hoc testing: ***pā¤0.001. Data appear in S4 and S5 Tables.
Fig 4.
The pseudocones of Drosophila ommatidia.
Loss of either a positive regulator [cycle (cyc01)] or a negative regulator [period (per01)] of the clock results in longer pseudocones compared to wild-type (WT) flies. Shown here are photomicrographs obtained from 5-day old flies.