SLBP and coloboma: For instance, choroid fissure closure is dependent on appropriately timed expression of genes in neural retina and retinal pigment epithelium [33,48]; and GG and SW, unpublished data); depigmentation of the ventral eye is associated with coloboma in slbp mutants suggesting a failure in differentiation of the retinal pigment epithelium cells may contribute to the coloboma.