GENE MUTATIONS 



ing carried in the homozygous state in the lab- 

 oratory for genetic studies. 



CANTALOUP, c (eyes). The first eye mutation 

 not in the orange locus was cantaloup, reces- 

 sive to wild-type. A female from orange stock 

 was treated by P. W. V/hiting in March, 1928, 

 with X-rays (dosage about 1100 R units). One 

 male with eyes resembling ivory was produced, 

 and subsequent tests proved it to be a new mu- 

 tation. At the time of emergence cantaloup eyes 

 appear white with a slight greenish tinge. 

 They quickly change to a light pink and fre- 

 quently darken so as to resemble orange or car- 

 rot, which will be described later. After death 

 they usually become black, differing in this 

 respect from orange and carrot, which show no 

 corresponding change in color. Ocelli are col- 

 orless. No other allele has been found at this 

 locus. In a mixed culture it may be confused 

 with ivory or with orange. Both males and fe- 

 males are fertile, and this type may be kept in 

 a homozygous condition. 



MAROON, ma (eyes). Another locus has become 

 marked by maroon, a form resembling dahlia. 

 This mutant was found in January, 1931. Maroon 

 has light ocelli with the compound eyes a very 

 dark red, so dark that it is often necessary to 

 use the light ocelli as an aid in separating it 

 from wild-type. This stock is male and female 

 fertile and can be kept homozygous. 



WHITE, wh (eyes). Another allelic series in- 

 volves white and carrot. White first appeared 

 in June, 1931, and resembles ivory in color 



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