YSX.YL, In(1)FM7LENR, y+ KS y vOf.KL BS.
male viable male fertile The FM7 inversions prevents euchromatic crossovers and the y+ and BS markers serve to detect recombinational events in the heterochromatin.
Craymer, April 1974.
Derived from C(1;YS)3, In(1)FM7 chromosome marked with y+ KS y- wa vOf and C(1;Y)1, In(1)EN progenitor marked with y . KL BS.
such that the wa y- base of FM7 is replaced by the w+ y.KL of YSX.YL, In(1)EN.