Studies on the isoallelic genes in the silkworm, Bombyx mori L

I. Mutant isoalleles at the +^w1 gene locus in the silkworm

Abstract

The eggs laid by white-1 strain (female) mate with normal strain (male) are pale colored. This pale coloration is due to the fact that a part of kynurenine which exists in white-1 strain egg is changed into 3-hydroxykynurenine and then into the pigment by the function of +^w₁ gene of the male strain. However, there are cases in which white-1 strain is colored scarcely or deeply according to the different strains of the male used. An analysis of genetical causes of such different pigmentations proved that the genes which control the pigmentation are closely linked with white-1 gene. Moreover, after researching their positional relations with w₂ and w₃ located on 10th chromosome, this kind of genes were ascertained to be multiple alleles or pseudoalleles of w₁ gene. From these results it has become evident that +^w1 gene consists of a number of isoallelic genes having different expression in strength and that +^w1 gene differs in a few strains.