Abstract
The chorion of gray egg is opaque and gray. Quantitatively CHIKUSHI (1960) analyzed sulphur of chorion of gray egg, showing smaller amount of sulphur than that of normal one, and suggested that the fragility of S-S linkage of chorion maternial may result in gray color as far as the mechanism of gray color pigmentation is concerned.
In this paper, authors examined the incorporation of radiochemicals, 3H-methionine and 35S-methionine, into the chorion of gray egg of the silkworm.
There was a great difference of 35S incorporation between the chorions of gray egg and normal one, but little difference of 3H-methionine between them. This finding confirms the result reported by CHIKUSHI. In general 35S was incorporated much into normal chorion. It was, therefore, clear that chorion protein contains a large amount of methionine, which plays an important role in chorion protein formation.
