The Seration of Fourth Chromosome Loci in Drosophila Melanogaster

Abstract

Tests of sv and spa make it apparent that their loci are in the distal section of the right arm between 102D1 and the tip of the chromosome at 102F in agreement with Morgan''s earlier evidence. Observations show that bt, ey and Mal lie in those parts of the R(ci)-24 section not included in R(+)-15 section. It is possible that the left break of R(+)-15 lies to the left of, or at the same place as R(ci)-24 and that bt, ey and Mal are in the section between 102C4 and 102D1. The following seriation is suggested with parentheses indicating the genes whose relative sequence is unknown: (ar, ci, gvl, Scn)-(bt, ey, Mal)-(sv, spa).