The lethal lemon and the lethal albino larvae1) show some phenotypical resemblance. In both, the
lem and the
al larvae, the mandibular cuticle does not develop properly, so that they cannot chew mulberry leaves and starve to death immediately after the first moulting. The lethal lemon larva contains in its epidermis a large amount of yellowish pigment which gives the body a yellowish color, while the lethal albino larva has a light brown color.
It has been confirmed in my previous experiments2), 3), 4) that +,
lem and
leml form a multi-allelic series. In order to investigate the genetical relation between the
al and the
leml genes, cross experiments between the two strains and between lemon strain (
lem/lem) and albino strain were carried out. From the experimental results it was found that
al gene does not locate on chromosome III. However, the linkage group to which
al gene belongs has not yet been clarified, although linkage tests of
al to several genes of the known other linkage groups were tried.
In another experiment5) it has been proved that the lethal lemon and lethal albino are different in their metabolic physiology. The gene
leml is mainly responsible for abnormal pterin formation, while the gene
al has a weaker capacity to form melanin. These physiological abnormalities have secondarily effects upon other metabolic processes such as abnormal formation of the cuticular layer of the hypodermis and produce somewhat similar expression.
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