Figure 1.—

Deletion polymorphism at the tip of 3L. Many chromosomes extracted from nature do not carry the putative G-protein coupled receptor mthl-8. The diversity of 3L subtelomeric sequences that we have found in North American chromosomes are shown. Browser tracks from top to bottom are as follows: (1) The positions of PCR markers used to map deletion breakpoints (black), (2) PCR markers also used to collect nucleotide polymorphism data (red; refer to Table 1 for locus names), (3) sequence determined to be present in numerous mthl8 deletion lines (black; line names in left-hand column), (4) protein-coding genes (blue), (5) D. melanogaster mRNAs (black), and (6) 12-way multiz alignment conservation scores (gray).