SCARLET, AN AUTOSOMAL EYE COLOR IDENTICAL 

 WITH SEX-LINKED VERMILION. 



D. E. LANCEFIELD, 

 COLUMBIA UNIVERSITY. 



Vermilion, a sex-linked eye color in Drosophila melanogaster 

 (ampelophila) , is duplicated in appearance by a new mutant 

 called scarlet (symbol s t ). The gene for scarlet is located in 

 the third chromosome to the left of dichaete. In spite of this 

 difference of location of the genes for the two eye colors they are 

 quite indistinguishable in appearance and can not be separated 

 from each other when mixed. Here we have a case in Drosophila 

 like the well-known case of the two whites in sweet peas. 



Upon crossing scarlet and vermilion, wild-type red is produced. 

 Reciprocal crosses between scarlet and vermilion cut-winged 

 flies from stock gave the following results in FI. A vermilion 

 cut male mated to a scarlet female produced offspring entirely 

 wild-type in appearance both for eyes and wings. Reciprocally 

 a scarlet male by a vermilion cut female gave wild-type daughters, 

 while the sons showed the sex-linked characteristics of the mother, 

 viz., vermilion eyes and cut wings. 



The next generation was not obtained because the writer 

 entered military service before completing it, but the significant 

 fact is demonstrated already that in Drosophila as elsewhere, 

 indistinguishable characters may be produced by differently 

 located genes. 



ORIGIN OF SCARLET AND PINKOID. 



The origin of scarlet was rather remarkable as it first appeared 

 in a strain which already contained eosin, and at the same time 

 was found a new eye color, pinkoid, whose gene is in the second 

 chromosome. In a cross of a bar male to an eosin miniature 

 female of non-disjunctional stock, there appeared in the offspring 

 38 females which were normal in appearance and did not have 

 the heterozygous bar eye. These females were due to reversion 



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