Coded illustration of changes in composition of ~ 18 kDa urinary proteins during early puberty in Sprague-Dawley male rats on high protein diet, represented in Figure 2A. identified proteins in this gel. Red, Major urinary protein; Dark blue, Rat urinary protein 1; Light blue, Rat urinary protein 2. Blank spaces indicate either no obvious band, or that no identification from tryptic digest analysis was obtained. Numbers refer to MASCOT score.