This file points to 4 pairs of files of the form    "?du*"
("?" is a single-character wildcard and "*" is a multiple-character wildcard.)

Crossing File	Backbone Overlay
1du2_A	1du2_A_sse
1dug_A	1dug_A_sse
1dus_A	1dus_A_sse
1duv_G	1duv_G_sse