Identification of novel random amplified polymorphic DNAs (RAPDs) on the Wchromosome of the domesticated silkworm, Bombyx mori, and the wild silkworm, B-mandarina, and their retrotransposable element-related nucleotide sequences

Genomic DNAs were compared between males and females of the domesticated si lkworm, Bombyx nori, strains C108, C137, 5137, p50, and WILD-W (constructed by crossing a wild silkworm, B. mandarina, female with a male of strain C1 08) by polymerase chain reaction (PCR) with 700 arbitrary 10-mer primers. F our female-specific RAPDs (W-Kabuki, W-Samurai, W-Kamikaze, and W-Yamato) w ere found. The sex chromosome formulas of B. mori and B. mandarina are ZW ( XY) for the female and ZZ (XX) for the male. The four female-specific RAPDs are assumed to be derived from the W chromosome because the other chromoso mes are shared by both sexes. A computer search for deduced amino acid sequ ences of these four RAPDs revealed that all of them showed homology to prev iously reported amino acid sequences encoded in known retrotransposable ele ments from various organisms.