REGIONAL LOCALIZATION OF NEURAL AND LENS ANTIGENS IN THE FROG EMBRYO IN RELATION TO INDUCTION

¹ Department of Zoology, State University of Iowa, Iowa City, Iowa

1. Anti-adult male frog brain and muscle sera absorbed to completion with male frog serum still react with female frog serum. It is believed that serum proteins common to the male and female may be in higher concentration in the female serum and hence account for this reaction.

2. Anti-brain serum, rendered organ-specific by absorption, reacted positively with test antigen preparations from four regions of the early frog gastrula (ectoderm, dorsal mesoderm, ventral mesoderm, and endoderm) and three regions of the hatched frog larva (head, trunk and gut). The proteins bearing brain determinate groups are apparently situated throughout the embryo at these stages.

3. The organ-specific anti-brain serum gave positive precipitin reactions with culture supernates from both larval heads and trunks which had been denuded of their epidermis and explanted for a period of a week. The proteins given off by these cultured heads and trunks bear similar determinate groups that react with the brain antibodies.

4. An absorbed organ-specific anti-frog lens serum, and an organ-specific anti-cattle lens serum, reacted with concentrated test antigen preparations from both the heads and trunks of hatched frog larvae. It seems that lens antigen, or protein bearing lens determinate groups, is localized in areas other than the lens-forming region.

5. The significance of these results is discussed.