TY - JOUR
T1 - Partial deletions of the W chromosome due to reciprocal translocation in the silkworm Bombyx mori
AU - Abe, H.
AU - Seki, M.
AU - Ohbayashi, F.
AU - Tanaka, N.
AU - Yamashita, J.
AU - Fujii, T.
AU - Yokoyama, T.
AU - Takahashi, M.
AU - Banno, Y.
AU - Sahara, K.
AU - Yoshido, A.
AU - Ihara, J.
AU - Yasukochi, Y.
AU - Mita, K.
AU - Ajimural, M.
AU - Suzuki, M. G.
AU - Oshiki, T.
AU - Shimada, T.
PY - 2005/8
Y1 - 2005/8
N2 - In the silkworm, Bombyx mori (female, ZW; male, ZZ), femaleness is determined by the presence of a single W chromosome, irrespective of the number of autosomes or Z chromosomes.The W chromosome is devoid of functional genes, except the putative female-determining gene (Fem). However, there are strains in which chromosomal fragments containing autosomal markers have been translocated on to W. In this study, we analysed the W chromosomal regions of the Zebra-W strain (T(W;3)Ze chromosome) and the Black-egg-W strain (T(W;10)+w-2 chromosome) at the molecular level. Initially, we undertook a project to identify W-specific RAPD markers, in addition to the three already established W-specific RAPD markers (W-Kabuki, W-Samurai and W-Kamikaze). Following the screening of 3648 arbitrary 10-mer primers, we obtained nine W-specific RAPD marker sequences (W-Bonsai, W-Mikan, W-Musashi, W-Rikishi, W-Sakura, W-Sasuke, W-Yukemuri-L, W-Yukemuri-S and BMC1-Kabuki), almost all of which contained the border regions of retrotransposons, namely portions of nested retrotransposons. We confirmed the presence of eleven out of twelve W-specific RAPD markers in the normal W chromosomes of twentyfive silkworm strains maintained in Japan.These results indicate that the W chromosomes of the strains in Japan are almost identical in type.The Zebra-W strain (T(W;3)Ze chromosome) lacked the W-Samurai and W-Mikan RAPD markers and the Black-egg-W strain (T(W;10)+w-2 chromosome) lacked the W-Mikan RAPD marker.These results strongly indicate that the regions containing the W-Samurai and W-Mikan RAPD markers or the W-Mikan RAPD marker were deleted in the T(W;3)Ze and T(W;10)+w-2 chromosomes, respectively, due to reciprocal translocation between the W chromosome and the autosome. This deletion apparently does not affect the expression of Fem; therefore, this deleted region of the W chromosome does not contain the putative Fem gene.
AB - In the silkworm, Bombyx mori (female, ZW; male, ZZ), femaleness is determined by the presence of a single W chromosome, irrespective of the number of autosomes or Z chromosomes.The W chromosome is devoid of functional genes, except the putative female-determining gene (Fem). However, there are strains in which chromosomal fragments containing autosomal markers have been translocated on to W. In this study, we analysed the W chromosomal regions of the Zebra-W strain (T(W;3)Ze chromosome) and the Black-egg-W strain (T(W;10)+w-2 chromosome) at the molecular level. Initially, we undertook a project to identify W-specific RAPD markers, in addition to the three already established W-specific RAPD markers (W-Kabuki, W-Samurai and W-Kamikaze). Following the screening of 3648 arbitrary 10-mer primers, we obtained nine W-specific RAPD marker sequences (W-Bonsai, W-Mikan, W-Musashi, W-Rikishi, W-Sakura, W-Sasuke, W-Yukemuri-L, W-Yukemuri-S and BMC1-Kabuki), almost all of which contained the border regions of retrotransposons, namely portions of nested retrotransposons. We confirmed the presence of eleven out of twelve W-specific RAPD markers in the normal W chromosomes of twentyfive silkworm strains maintained in Japan.These results indicate that the W chromosomes of the strains in Japan are almost identical in type.The Zebra-W strain (T(W;3)Ze chromosome) lacked the W-Samurai and W-Mikan RAPD markers and the Black-egg-W strain (T(W;10)+w-2 chromosome) lacked the W-Mikan RAPD marker.These results strongly indicate that the regions containing the W-Samurai and W-Mikan RAPD markers or the W-Mikan RAPD marker were deleted in the T(W;3)Ze and T(W;10)+w-2 chromosomes, respectively, due to reciprocal translocation between the W chromosome and the autosome. This deletion apparently does not affect the expression of Fem; therefore, this deleted region of the W chromosome does not contain the putative Fem gene.
KW - Bombyx mori
KW - RAPD
KW - Reciprocal translocation
KW - Retrotransposon
KW - Sex chromosome
KW - W chromosome
UR - http://www.scopus.com/inward/record.url?scp=24044515592&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2583.2005.00565.x
DO - 10.1111/j.1365-2583.2005.00565.x
M3 - Article
C2 - 16033428
AN - SCOPUS:24044515592
SN - 0962-1075
VL - 14
SP - 339
EP - 352
JO - Insect Molecular Biology
JF - Insect Molecular Biology
IS - 4
ER -