The following information accompanied stocks donated to the Bloomington Stock Center by Wouter Ferro, Leiden University Medical Center (12/02). A chromosome with the markers st1 in1 kniri-1 pp was mutagenized with EMS and screened for recessive lethal and MMS-sensitive mutations that fail to complement the chromosome Df(3R)X3F, P{RP49}A3-84F. Ten lethal loci and one MMS-sensitive locus were defined. Locus Number of alleles Including alleles l(3)99DEa 3 l(3)99DEa7-6 l(3)99DEb 4 l(3)99DEb3-2 l(3)99DEc 1 l(3)99DEc3-13 l(3)99DEd 7 l(3)99DEd3-18, l(3)99DEd6-8 l(3)99DEe 3 l(3)99DEe6-4 l(3)99DEf 2 l(3)99DEf5-1 l(3)99DEg 1 l(3)99DEg7-14 l(3)99DEh 1 l(3)99DEh7-20 l(3)99DEi 1 l(3)99DEi9-27 l(3)99DEj 1 l(3)99DEj10-28 mus313 1 mus3136-12 Note that l(3)99DEh7-20 was semilethal in combination with l(3)99DEb3-2. Unfortunately, the l(3)99DEg7-14 line was lost. In addition, one allele of warts, wts3-17, was isolated in this screen.