TY - JOUR
T1 - Sex determination in the silkworm, Bombyx mori
T2 - A female determinant on the W chromosome and the sex-determining gene cascade
AU - Fujii, Tsuguru
AU - Shimada, Toru
N1 - Funding Information:
We thank Drs. M.G. Suzuki, S. Funaguma, and F. Ohbayashi, and Ms. E. Fujita for sharing unpublished results. Our studies on sex determination in the silkworm are supported by the NIAS/MAFF Insect Technology Program (to T.S.), Grants-in-Aid for Scientific Research from MEXT/JSPS (No. 17018007 and 16208006 to T.S.), JSPS Research Fellowships for Young Scientists (1611612 to S.F.) and the Professional Program for Agricultural Bioinformatics, JST, Japan.
PY - 2007/6
Y1 - 2007/6
N2 - In insects, the sex is determined completely by genetic mechanisms, which at least in somatic tissues, are cell autonomous. The sex of the silkworm, Bombyx mori, is strongly controlled by the presence of the W chromosome. Genetic studies using translocations and deletions of W suggested that a presumptive feminizing gene (Fem) is located in a limited region of the W chromosome. Recent genomic studies revealed a small number of potential candidates for the Fem gene in this region. In addition, a Bombyx homologue of the Drosophila sex determining gene doublesex has been identified on an autosome and analyzed. Whereas the Drosophila doublesex gene is regulated by activation of splicing in females, the Bombyx doublesex gene (Bmdsx) encodes female- and male-specific mRNAs regulated via male-specific repression of splicing. The vitellogenin gene (Vg) is a target of the BmDSX protein, which directly binds to the Vg promoter. Furthermore, as ectopic expression of the male-type Bmdsx induces male-like transformation of the sexual organs, BmDSX may control sex-specific morphological characteristics in Bombyx. This suggests that although upstream events in Drosophila and Bombyx sex determination differ, similarities between the two species do exist in downstream genetic control of sex determination.
AB - In insects, the sex is determined completely by genetic mechanisms, which at least in somatic tissues, are cell autonomous. The sex of the silkworm, Bombyx mori, is strongly controlled by the presence of the W chromosome. Genetic studies using translocations and deletions of W suggested that a presumptive feminizing gene (Fem) is located in a limited region of the W chromosome. Recent genomic studies revealed a small number of potential candidates for the Fem gene in this region. In addition, a Bombyx homologue of the Drosophila sex determining gene doublesex has been identified on an autosome and analyzed. Whereas the Drosophila doublesex gene is regulated by activation of splicing in females, the Bombyx doublesex gene (Bmdsx) encodes female- and male-specific mRNAs regulated via male-specific repression of splicing. The vitellogenin gene (Vg) is a target of the BmDSX protein, which directly binds to the Vg promoter. Furthermore, as ectopic expression of the male-type Bmdsx induces male-like transformation of the sexual organs, BmDSX may control sex-specific morphological characteristics in Bombyx. This suggests that although upstream events in Drosophila and Bombyx sex determination differ, similarities between the two species do exist in downstream genetic control of sex determination.
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U2 - 10.1016/j.semcdb.2007.02.008
DO - 10.1016/j.semcdb.2007.02.008
M3 - Review article
C2 - 17446095
AN - SCOPUS:34547683547
SN - 1084-9521
VL - 18
SP - 379
EP - 388
JO - Seminars in Cell and Developmental Biology
JF - Seminars in Cell and Developmental Biology
IS - 3
ER -