Carries wild-type alleles of genes in 1A, y+ (or y31d) and ac+ distally and wild-type alleles of genes in 1A, y, and ac+ proximally on long arm plus heterochromatic short arm of In(1)EN. Carries bb+ in distal heterochromatin derived from In(1)sc8 and a mild allele of bb in proximal heterochromatin derived from In(1)EN.
1B2-3;20FL1A;20;20FR.