title: Zebrafish cone-rod (crx) homeobox gene promotes retinogenesis.
abstract: The mammalian Cone-rod homeobox (Crx) gene is a divergent member of the Otx gene family known to be involved in differentiation and survival of retinal photoreceptors and photoentrainment of circadian rhythms. Zebrafish have two genes in the Otx5/crx orthology class, and we previously showed that crx can transactivate rhodopsin expression in vitro, and that otx5 (orthodenticle-related gene), but not crx, regulates expression of circadian genes in the pineal. Here, we show that zebrafish crx does not regulate expression of opsins and other photoreceptor-specific genes in the pineal. We further show that crx is expressed in proliferating retinal progenitors and may be involved in patterning the early optic primordium and in promoting the differentiation of retinal progenitors, including photoreceptors. These results suggest novel functions for zebrafish crx during retinal specification and differentiation.
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109-0616, USA.
authors.forename: Yu-chi
authors.initials: YC
authors.lastname: Shen
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Raymond
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D012160:Retina / Q000196:embryology* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology* / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; D015534:Trans-Activators; C109288:cone rod homeobox protein