Fig. 1. A physical map of the yps gene, and the yps^JM2 deletion mutation. yps was mapped to polytene region 68F3-F7 by chromosome in situ hybridization. Three deletions that uncover yps are indicated: Df(3L)vin4, Df(3L)vin7 and Df(3L)BK9. Alignment of known yps cDNAs with genomic sequence predicts the exon structure of yps shown in the diagram. Each division of the black line represents 100 bp of genomic DNA, while the thick green and blue boxes represent exons. The precise locations of the 5' end of the transcripts have not been mapped. The cold shock domain (CSD) is shown in light blue, and the start (ATG) and stop (TAG) codons are marked. The EP(3)3078 insertion (represented by a red triangle) was mapped 259 bp upstream of the start codon (BDGP). The limits of the yps^JM2 deletion are represented by the blue line at the bottom. The positions of PCR primers used for the excision screen (see text) are indicated by the red arrows labeled a-d. The chromosome drawing is reproduced after the drawings of Bridges (Bridges, 1941).