Construction of linkage map of the silkworm, Bombyx mori, using RAPD markers

Abstract

A genetic linkage map of the silkworm. Bombyx mori, was constructed by using RAPD markers. Fifty eight valuable polymorphic bands were detected in the silkworm strains (J111 and Galwon) by screening 100 decamer primers and selecting 35 decamer random primers. On the F2 generation, segregation ratio of these bands was about 3:1 in a chi square test, showing Mendelian inheritance. The MAPMAKER program sorted 58 bands into 9 linkage groups and 28 unlinked loci at minimum LOD score 4.5 and determined orders of loci in each linkage group which contained 2 to 8 RAPD markers. The map consists of 30 markers and the sum of map distance was about 309.3 cM. The RAPD map has a low density of 10.3 cM on average, which correspond to 5.15 Mbps. And then results obtained above suggest that this linkage map is one of the fundamental index for the future genome analysis in the silkworm, Bombyx mori.