Sall3 controls cone photoreceptor and horizontal cell differentiation

ABSTRACT: Transcription factors have been implicated in the specification and differentiation of all cells in the mammalian retina with several transcription factors controlling the development of multiple neuronal subclasses. Horizontal cells and cone photoreceptors share a particularly intimate functional relationship but have been previously thought to develop through separate and distinct intrinsic molecular processes. We demonstrate that the zinc finger transcription factor Sall3 regulates development of both S-cone photoreceptors and horizontal cells. Our data shows that loss of function of Sall3 down-regulates the horizontal cell specific transcription factor Lhx1 and subsequently causes ectopic formation of horizontal-like wide-field amacrine cells partially phenocopying Lhx1-/- mice. Additionally, horizontal cells which laminate appropriately in Sall3 knockout mice show abnormal horizontal cell gene expression and failures in dendritic arborization. Over-expression of Sall3 also partially re-specifies cells to a horizontal-like wide-field amacrine fate. Intriguingly, Sall3 loss of function experiments also generated a massive reduction in the number of S-cone photoreceptors with remaining S-cones showing deficiencies in S-cone gene expression and morphology. Conversely, over-expression of Sall3 resulted in the ectopic expression of the S-cone specific genes S-opsin (Sop) and cone arrestin (Arr3) in electroporated cells. Our studies reveal that Sall3 regulates aspects of horizontal cell development in two ways: first, by maintaining Lhx1 expression, and second, by directly regulating expression of horizontal cell specific genes. We also show that Sall3 is an essential regulator of S-cone development in the mammalian retina and a potent activator of Sop and Arr3.

ORGANISM(S): Mus musculus

PROVIDER: GSE24083 | GEO | 2011/09/10

SECONDARY ACCESSION(S): PRJNA130211

REPOSITORIES: GEO