%0 Journal Article
%T PRE-1, a cis element sufficient to enhance cone- and rod- specific expression in differentiating zebrafish photoreceptors
%A Maria E Morrissey
%A Sara Shelton
%A Susan E Brockerhoff
%A James B Hurley
%A Breand¨¢n N Kennedy
%J BMC Developmental Biology
%D 2011
%I BioMed Central
%R 10.1186/1471-213x-11-3
%X A 0.5 kb T¦ÁC promoter fragment is sufficient to direct cone-specific expression in transgenic larvae. Within this minimal promoter, we identify photoreceptor regulatory element-1 (PRE-1), a unique 41 bp sequence. PRE-1 specifically binds nuclear factors expressed in ocular tissue. PRE-1 is not required for cone-specific expression directed from a 2.5 kb T¦ÁC promoter. However, PRE-1-like sequences, with potential functional redundancy, are located in this 2.5 kb promoter. PRE-1-rho which has the highest sequence and structural homology to PRE-1 is located in the rhodopsin promoter. Surprisingly, PRE-1 and PRE-1-rho are functionally distinct. We demonstrate that PRE-1, but not PRE-1-rho, is sufficient to enhance expression from a heterologous UV cone promoter. PRE-1 is also sufficient to enhance expression from a heterologous rhodopsin promoter without altering its rod photoreceptor specificity. Finally, mutations in consensus E-box and Otx sites prevent PRE-1 from forming complexes with eye nuclear protein and enhancing photoreceptor expression.PRE-1 is a novel cis-regulatory module that is sufficient to enhance the initiation of photoreceptor-specific gene expression in differentiating rod and cone photoreceptors.Photoreceptors are specialised sensory neurons that enable images of the external environment to be captured. Structurally, cone and rod photoreceptors appear grossly similar. Both have outer segments rich in photosensitive membranes, inner segments rich in transport and metabolic machinery, and synaptic termini that chemically transmit light signals to downstream neurons [1]. However, cone and rod photoreceptors function distinctly. Rods are specialised to function in low-light, whereas cones enable colour vision and visual acuity [2]. These functional differences are partly explained by the distinct morphological specialisations of outer segments and synaptic termini present in rods or cones [1]. In addition, unique transcripts encode rod- or cone-specifi
%U http://www.biomedcentral.com/1471-213X/11/3