Western blots showing protein expression profiles for BMP4 (A) and BMP7 (B) in retina, RPE, and choroid from adolescent chicks, prepared under reducing conditions. Lane M was loaded with protein marker. In blot A, lane 1 was loaded with denatured, reduced BMP4 protein (0.02 µg), lanes 2 and 3 with mouse brain and chick brain respectively, and lanes 4 to 6 with chick retina, RPE, and choroid, respectively. In blot B, lane 1 was loaded with human kidney lysates, and lanes 2 and 3 were loaded with mouse and chick brain, respectively. Lanes 4 to 6 were loaded with chick retina, RPE, and choroid, respectively. MB, mouse brain; CB, chick brain; Ret, retina; Cho, choroid; HK, human kidney lysates.