抄録
(1) One translocation line was discovered in the natural state. It may be explained as due to the transference of a small piece of the left end of the third chromosome to the right of the fourth chromosome.
(2) The classes derived from the translocation line show the characteristics as given in the accompanying table. (N=normal chromosome, T3=third chromosome with translocation, T4=fourth chromosome with translocation.)
Genotypic constitution Appearance Viability Fertility
N/N, N/N Normal 100 High
N/T3, N/T4 Normal 100 High
N/T3, N/N Diminutive flies 3 Very low
N/N, N/T4 Slender than normal in appearance 84 High
T3/T3, N/T4 Diminutive flies with scoop bristles 3 Very low
T3/T3, T4/T4 - Dies -
T3/T3, N/N - " -
N/T3, T4/T4 - " -
N/N, T4/T4 - " -
(3) This translocation line reveals that the duplication and the deficiency of a small piece of the chromosome give rise to deviations in opposite directions in respect to various points of the external feature from the normal state.
(4) The appearance of two mutations, the scoop gene and a lethal gene, seems to indicate that the natural mutations are also likely to be associated with the loci of the breakages in translocations.
