transcription factor (TF) family, has been shown to control brain patterning. and processes for this control. These include Sonic hedgehog a (Shha) [4], cell adhesion [5], cell polarity regulation [6] and chromatin remodeling [7]. A recent microarray SC-514 manufacture study of chromatin remodeling on zebrafish retinal differentiation have identified 731 genes regulated by Smarca4, a component of chromatin remodeling complex [8]. In Smarca4-deficient retinas, all retinal cell types can be specified and many of them are located in the correct location, but they fail to terminally differentiate [9]; at the same time, retinal lamination is compromised. Thus, Smarca4-regulated genes may play important roles in these terminal differentiation, retinal lamination and patterning SC-514 manufacture processes [8]. For example, several members in the (and genes in both invertebrate and vertebrate have been shown to be an important mediator for embryo patterning. For example, it has been shown that regulates the compartmentalization of SC-514 manufacture midbrain and hindbrain [10], [12], [13]. Several genes are expressed in the retina and regulate its development. These include and in zebrafish [8], [14], F2rl1 [15], [16], [17] and all six genes in mouse [18]. Most of these genes are expressed in GCs region, except for mice that is expressed a subset of outer retinal cells in addition to GCs (http://zfin.org) and zebrafish that is only expressed in INL [17]. The regulation of several genes by Smarca4 in retina [8] hints at the possibility that they may regulate retinal differentiation and lamination. Indeed, the propagation of the Shha neurogenic waves in zebrafish retina [4], [20] is mediated by the expression of and in turn in GCs [15], [16]; and the knockdown of these two genes compromises retinal differentiation and lamination that resembles the mutants. The exclusive expression of zebrafish in the INL at 52 hpf [17] is particularly interesting because retinal lamination is established at around this stage. Together with the issues in retinal development in an initial Irx7 knockdown [8], these observations suggest two non-mutually exclusive possibilities. First, is essential for retinal patterning and formation of retinal lamination. Second, is responsible for INL cells differentiation, which in turn regulates the formation of retinal lamination. The purpose of this study was to define the role of in retinal development and lamination. The results indicate that is SC-514 manufacture necessary for differentiation of INL and ONL and projection of neuronal processes into the plexiform layers. Compromising these processes may in turn disrupt retinal lamination. Results is specifically expressed in the INL during retinal development expression was observed in the anterior dorsal retina (Figure 1B, black arrowhead) by 43 hpf, when most cells in the prospective INL have withdrawn from the cell cycle. At 46 hpf, began to express in the posterior ventral retina (Figure 1C, black arrowhead). Then, its expression domain in both anterior and posterior retina gradually expanded to the dorsal side from 46 to 52 hpf (Figure 1C, D, E and J). At these stages, seemed to be largely excluded from the basal INL region and was not expressed homogeneously in the remaining INL cells. When retinal lamination became apparent at 52 hpf, appeared in the posterior dorsal retina, the last region to express (compare Figure 1D and E, red arrowheads). By this stage, the initial expression wave of in the prospective INL is completed. Since this wave overlaps with the cell cycle withdrawal and cell differentiation in INL, it is possible that regulates these processes. Figure 1 is specifically expressed in the prospective INL during zebrafish retinal development. Then, expression was gradually restricted to.