Abstract
Changes in uric acid content and xanthine dehydrogenase activity of the silkworm egg were investigated during embryonic development.
1. The uric acid content of the egg decreases gradually until the blastokinesis stage, then increases and reaches the maximum level at just body pigmentation stage.
2. Xanthine dehydrogenase activity increases gradually until about middle stage, after that increases markedly, but declines a little at body pigmentation stage.
3. These changes of uric acid content and xanthine dehydrogenase activity during embryonic development in the silkworm egg were discussed with respect to the physiological function of uric acid in the silkworm egg.
