title: Detachment analysis of the translocated W chromosome shows that the female-specific randomly amplified polymorphic DNA (RAPD) marker, female-218, is derived from the second chromosome fragment region of the translocated W chromosome of the sex-limited p(B) silkworm (Bombyx mori ) strain.
abstract: The sex chromosomes of the silkworm, Bombyx mori, are designated ZW for the female and ZZ for the male. We previously characterized a female-specific randomly amplified polymorphic DNA (RAPD) marker, designated Female-218, from the translocation-bearing W chromosomes. These W chromosomes contain a region of the second chromosome, which carries visible larval markers of the p loci. We used strain TWPB in which female larvae have black skin due to the p(B) gene (T(W;2)p(B), +p/+p) while male larvae have whitish skin (+p/+p). To determine whether the Female-218 RAPD marker is derived from the "W region" or a "second chromosome fragment", we induced a detachment of the translocated W chromosome, T(W;2)p(B), by treating the eggs with hot water at an early developmental stage. After hot water treatment, we obtained 27 white female larvae out of 4850 female larvae. The Female-218 RAPD marker was not amplified in 26 out of 27 white female larvae, and was amplified from one white female larva. Moreover, we obtained 11 black male larvae out of 5377 male larvae. Eight out of 11 black male larvae became adult moths, and the Female-218 RAPD marker was amplified from all eight male moths. Examination of the genetic relationship between the Female-218 RAPD marker and the second chromosome fragment of the translocated W chromosome strongly indicates that the Female-218 RAPD marker is amplified from the region of second chromosome fragment of the T(W;2)p(B) chromosome.
authors.affiliation: Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Abe
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Irobe
authors.forename: Katsuji
authors.initials: K
authors.lastname: Saito
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Tanaka
authors.forename: Shinya
authors.initials: S
authors.lastname: Kawai
authors.forename: Fumi
authors.initials: F
authors.lastname: Ohbayashi
authors.forename: Toru
authors.initials: T
authors.lastname: Shimada
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Oshiki
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics* / Q000254:growth & development; D005260:Female; D005819:Genetic Markers; D007814:Larva / Q000235:genetics; D008297:Male; D019105:Random Amplified Polymorphic DNA Technique; D012730:Sex Chromosomes / Q000235:genetics*; D014178:Translocation, Genetic
chemical_list: D005819:Genetic Markers