title: BARHL2 differentially regulates the development of retinal amacrine and ganglion neurons.
abstract: Through transcriptional regulations, the BarH family of homeodomain proteins play essential roles in cell fate specification, cell differentiation, migration, and survival. Barhl2, a member of the Barh gene family, is expressed in retinal ganglion cells (RGCs), amacrine cells (ACs), and horizontal cells. Here, to investigate the role of Barhl2 in retinal development, Barhl2-deficient mice were generated. Analysis of AC subtypes in Barhl2-deficient retinas suggests that Barhl2 plays a critical role in AC subtype determination. A significant reduction of glycinergic and GABAergic ACs with a substantial increase in the number of cholinergic ACs was observed in Barhl2-null retinas. Barhl2 is also critical for the development of a normal complement of RGCs. Barhl2 deficiency resulted in a 35% increase in RGCs undergoing apoptosis during development. Genetic analysis revealed that Barhl2 functions downstream of the Atoh7-Pou4f3 regulatory pathway and regulates the maturation and/or survival of RGCs. Thus, BARHL2 appears to have numerous roles in retinal development, including regulating neuronal subtype specification, differentiation, and survival.
authors.affiliation: University of Rochester Eye Institute, University of Rochester, Rochester, New York 14642, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Ding
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Xie
authors.forename: Richard T
authors.initials: RT
authors.lastname: Libby
authors.forename: Ning
authors.initials: N
authors.lastname: Tian
authors.forename: Lin
authors.initials: L
authors.lastname: Gan