R.F. Grell, 1954.
Male lethal owing to presence of two multilocus deficiencies in In(1)FM3, which may be covered by Dp(1;Y)BSYy+ or by Dp(1;Ybb-)BS and Dp(1;Y)y+ (Schalet, quoted in FBrf0066905). Effectively suppresses crossing over in the X chromosome. Useful for balancing sex-linked recessive, female-sterile mutants and, in combination with Dp(1;Y)BSYy+, for balancing sex-linked recessive lethal and male-sterile mutants.