The mouse Crx 5'-upstream transgene sequence directs cell-specific and developmentally regulated expression in retinal photoreceptor cells.
Crx, an Otx-like homeobox gene, is expressed primarily in the photoreceptors of the retina and in the pinealocytes of the pineal gland. The CRX homeodomain protein is a transactivator of many photoreceptor/pineal-specific genes in vivo, such as rhodopsin and the cone opsins. Mutations in Crx are associated with the retinal diseases, cone-rod dystrophy-2, retinitis pigmentosa, and Leber's congenital amaurosis, which lead to loss of vision. We have generated transgenic mice, using 5'- and/or 3'-flanking sequences from the mouse Crx homeobox gene fused to the beta-galactosidase (lacZ) reporter gene, and we have investigated the promoter function of the cell-specific and developmentally regulated expression of Crx. All of the independent transgenic lines commonly showed lacZ expression in the photoreceptor cells of the retina and in the pinealocytes of the pineal gland. We characterized the transgenic lines in detail for cell-specific lacZ expression patterns by 5-bromo-4-chloro-3-indolyl beta-D-galactoside staining and lacZ immunostaining. The lacZ expression was observed in developing and developed photoreceptor cells. This observation was confirmed by coimmunostaining of dissociated retinal cells with the lacZ and opsin antibodies. The ontogeny analysis indicated that the lacZ expression completely agrees with a temporal expression pattern of Crx during retinal development. This study demonstrates that the mouse Crx 5'-upstream genomic sequence is capable of directing a cell-specific and developmentally regulated expression of Crx in photoreceptor cells.
Furukawa
Akiko
A
Center for Developmental Biology and Kent Waldrep Foundation Center for Basic Research on Nerve Growth and Regeneration, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9133, USA.
Koike
Chieko
C
Lippincott
Pia
P
Cepko
Constance L
CL
Furukawa
Takahisa
T
D020121:5' Untranslated Regions / Q000235:genetics*; D000818:Animals; D025461:Feedback, Physiological / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D007763:Lac Operon; D051379:Mice; D008822:Mice, Transgenic; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology / Q000378:metabolism; D010870:Pineal Gland / Q000166:cytology / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology; D012045:Regulatory Sequences, Nucleic Acid / Q000502:physiology; D012160:Retina / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation / Q000502:physiology; D019076:Transgenes
D020121:5' Untranslated Regions; D018398:Homeodomain Proteins; D015534:Trans-Activators; C109288:cone rod homeobox protein