Fig. 10. Schematic drawing of the renewal of protein in rod outer segments. Black dots indicate sites of radioactive amino acids incorporated into newly synthesized rhodopsin, as revealed by light microscopic radioautography. In the human, the time required for transit of a band of newly synthesized rhodopsin from the base of the outer segment (C) to its tip (E) is approximately 2 weeks. (Anderson RE [ed]: Biochemistry of the Eye. San Francisco: American Academy of Ophthalmology, 1983:172.)