THE PHENOTYPES OF HOMOZYGOTES AND HEMIZYGOTES OF POSITION ALLELES AND OF HETEROZYGOTES BETWEEN ALLELES IN NORMAL AND TRANSLOCATED POSITIONS

Abstract

XCEPT for rare cases of additive expression, it is a rule which is nearly E without exception that the heterozygote between two alleles is phenotypically either identical with one of the two homozygotes or intermediate between them. In experiments involving position effects of the fourth chromosome normal allele of cubitus interruptus (6; ) of Drosophila melanogaster, several cases have been found where this rule does not hold but where the heterozygotes lie phenotypically outside of the range delimited by the homozygotes.