Developmental patterns of protein expression in photoreceptors implicate distinct environmental versus cell-intrinsic mechanisms.
The present study has examined the spatial and temporal expression patterns of various proteins associated with the structure and function of mature photoreceptor outer segments in the developing ferret's retina using immunocytochemistry and RT-PCR. One set of proteins, including rod opsin, arrestin, and recoverin, was detected progressively in photoreceptors as they became postmitotic, being expressed well before the differentiation of outer segments. A second set of proteins, including beta- and gamma-transducin, cGMP-phosphodiesterase, phosducin, rhodopsin kinase, rod cGMP-gated cation channel protein, and peripherin, displayed a contrasting temporal onset and pattern of spatial emergence. These latter proteins first became detectable either shortly before or coincident with outer segment formation, and were expressed simultaneously in both older and younger photoreceptor cells. A third set, the short wavelength-sensitive (SWS) and medium wavelength-sensitive (MWS) cone opsin proteins, was the last to be detected, but materialized in a spatio-temporal pattern reminiscent of the neurogenetic gradient of the cones. These different spatial and temporal patterns indicate that cellular maturation must play a primary role in regulating the onset of expression of some of these proteins, while extrinsic signals must act to coordinate the expression of other proteins across photoreceptors of different ages.
Johnson
P T
PT
Neuroscience Research Institute, and Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, 93106-5060, USA.
Williams
R R
RR
Reese
B E
BE
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D019393:Arrestin / Q000096:biosynthesis / Q000235:genetics; D002135:Calcium-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D005136:Eye Proteins / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D005289:Ferrets; D051606:G-Protein-Coupled Receptor Kinase 1; D020555:GTP-Binding Protein Regulators; D018507:Gene Expression Regulation, Developmental; D051597:Hippocalcin; D007381:Intermediate Filament Proteins / Q000096:biosynthesis / Q000235:genetics; D008074:Lipoproteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D064531:Peripherins; D010750:Phosphoproteins / Q000096:biosynthesis / Q000235:genetics; D011247:Pregnancy; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D051603:Recoverin; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012374:Rod Cell Outer Segment / Q000254:growth & development* / Q000378:metabolism; D017299:Rod Opsins / Q000096:biosynthesis / Q000235:genetics; D015293:Transducin / Q000096:biosynthesis / Q000235:genetics
D019393:Arrestin; D002135:Calcium-Binding Proteins; D017931:DNA Primers; D005136:Eye Proteins; D020555:GTP-Binding Protein Regulators; D007381:Intermediate Filament Proteins; D008074:Lipoproteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D064531:Peripherins; D010750:Phosphoproteins; D012333:RNA, Messenger; D017299:Rod Opsins; C065631:phosducin; D051603:Recoverin; D051597:Hippocalcin; D011494:Protein Kinases; D051606:G-Protein-Coupled Receptor Kinase 1; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D015293:Transducin