PubMed:17901928 JSONTXT

{"project":"silkwormbase","denotations":[{"id":"T1","span":{"begin":71,"end":82},"obj":"Species:7091"},{"id":"T2","span":{"begin":108,"end":116},"obj":"Species:7091"},{"id":"T3","span":{"begin":117,"end":128},"obj":"Species:7091"},{"id":"T4","span":{"begin":734,"end":742},"obj":"Species:7091"},{"id":"T5","span":{"begin":209,"end":212},"obj":"BMO_00546"},{"id":"T6","span":{"begin":227,"end":230},"obj":"BMO_00546"},{"id":"T7","span":{"begin":454,"end":459},"obj":"BMO_00310"},{"id":"T9","span":{"begin":476,"end":478},"obj":"BMO_00310"},{"id":"T12","span":{"begin":792,"end":794},"obj":"BMO_00310"},{"id":"T23","span":{"begin":1732,"end":1735},"obj":"BMO_00546"},{"id":"T24","span":{"begin":184,"end":207},"obj":"BMO_00546"}],"text":"Identification of the female-determining region of the W chromosome in Bombyx mori.\nThe W chromosome of the silkworm Bombyx mori is devoid of functional genes, except for the putative female-determining gene (Fem). To localize Fem, we investigated the presence of W-specific DNA markers on strains in which an autosomal fragment containing dominant marker genes was attached to the W chromosome. We produced new W-chromosomal fragments from the existing Zebra-W strain (T(W;3)Ze chromosome) by X-irradiation, and then carried out deletion mapping of these and sex-limited yellow cocoon strains (T(W;2)Y-Chu, -Abe and -Ban types) from different Japanese stock centers. Of 12 RAPD markers identified in the normal W chromosomes of most silkworm strains in Japan, the newly irradiated W(B-YL-YS)Ze chromosome contained three, the T(W;2)Y-Chu chromosome contained six, and the T(W;2)Y-Abe and -Ban chromosomes contained only one (W-Rikishi). To investigate the ability of the reduced W-chromosome translocation fragments to form heterochromatin bodies, which are found in nuclei of normal adult female sucking stomachs, we examined cells of the normal type p50 strain and the T(W;2)Y-Chu and -Abe strains. A single sex heterochromatin body was found in nuclei of p50 females, whereas we detected only small sex heterochromatin bodies in the T(W;2)Y-Chu strain and no sex heterochromatin body in the T(W;2)Y-Abe strain. Since adult females of all strains were normal and fertile, we conclude that only extremely limited region, containing the W-Rikishi RAPD sequence of the W chromosome, is required to determine femaleness. Based on a comparison of the normal W-chromosome and 7 translocation and W-deletion strains we present a map of Fem relative to the 12 W-specific RAPD markers."}

{"project":"silkworm_phenotype","denotations":[{"id":"T24","span":{"begin":184,"end":207},"obj":"BMO_00546"},{"id":"T23","span":{"begin":1732,"end":1735},"obj":"BMO_00546"},{"id":"T12","span":{"begin":792,"end":794},"obj":"BMO_00310"},{"id":"T9","span":{"begin":476,"end":478},"obj":"BMO_00310"},{"id":"T7","span":{"begin":454,"end":459},"obj":"BMO_00310"},{"id":"T6","span":{"begin":227,"end":230},"obj":"BMO_00546"},{"id":"T5","span":{"begin":209,"end":212},"obj":"BMO_00546"},{"id":"T4","span":{"begin":734,"end":742},"obj":"Species:7091"},{"id":"T3","span":{"begin":117,"end":128},"obj":"Species:7091"},{"id":"T2","span":{"begin":108,"end":116},"obj":"Species:7091"},{"id":"T1","span":{"begin":71,"end":82},"obj":"Species:7091"}],"text":"Identification of the female-determining region of the W chromosome in Bombyx mori.\nThe W chromosome of the silkworm Bombyx mori is devoid of functional genes, except for the putative female-determining gene (Fem). To localize Fem, we investigated the presence of W-specific DNA markers on strains in which an autosomal fragment containing dominant marker genes was attached to the W chromosome. We produced new W-chromosomal fragments from the existing Zebra-W strain (T(W;3)Ze chromosome) by X-irradiation, and then carried out deletion mapping of these and sex-limited yellow cocoon strains (T(W;2)Y-Chu, -Abe and -Ban types) from different Japanese stock centers. Of 12 RAPD markers identified in the normal W chromosomes of most silkworm strains in Japan, the newly irradiated W(B-YL-YS)Ze chromosome contained three, the T(W;2)Y-Chu chromosome contained six, and the T(W;2)Y-Abe and -Ban chromosomes contained only one (W-Rikishi). To investigate the ability of the reduced W-chromosome translocation fragments to form heterochromatin bodies, which are found in nuclei of normal adult female sucking stomachs, we examined cells of the normal type p50 strain and the T(W;2)Y-Chu and -Abe strains. A single sex heterochromatin body was found in nuclei of p50 females, whereas we detected only small sex heterochromatin bodies in the T(W;2)Y-Chu strain and no sex heterochromatin body in the T(W;2)Y-Abe strain. Since adult females of all strains were normal and fertile, we conclude that only extremely limited region, containing the W-Rikishi RAPD sequence of the W chromosome, is required to determine femaleness. Based on a comparison of the normal W-chromosome and 7 translocation and W-deletion strains we present a map of Fem relative to the 12 W-specific RAPD markers."}

{"project":"silkworm","denotations":[{"id":"T1","span":{"begin":71,"end":82},"obj":"Species:7091"},{"id":"T2","span":{"begin":108,"end":116},"obj":"Species:7091"},{"id":"T3","span":{"begin":117,"end":128},"obj":"Species:7091"},{"id":"T4","span":{"begin":734,"end":742},"obj":"Species:7091"}],"text":"Identification of the female-determining region of the W chromosome in Bombyx mori.\nThe W chromosome of the silkworm Bombyx mori is devoid of functional genes, except for the putative female-determining gene (Fem). To localize Fem, we investigated the presence of W-specific DNA markers on strains in which an autosomal fragment containing dominant marker genes was attached to the W chromosome. We produced new W-chromosomal fragments from the existing Zebra-W strain (T(W;3)Ze chromosome) by X-irradiation, and then carried out deletion mapping of these and sex-limited yellow cocoon strains (T(W;2)Y-Chu, -Abe and -Ban types) from different Japanese stock centers. Of 12 RAPD markers identified in the normal W chromosomes of most silkworm strains in Japan, the newly irradiated W(B-YL-YS)Ze chromosome contained three, the T(W;2)Y-Chu chromosome contained six, and the T(W;2)Y-Abe and -Ban chromosomes contained only one (W-Rikishi). To investigate the ability of the reduced W-chromosome translocation fragments to form heterochromatin bodies, which are found in nuclei of normal adult female sucking stomachs, we examined cells of the normal type p50 strain and the T(W;2)Y-Chu and -Abe strains. A single sex heterochromatin body was found in nuclei of p50 females, whereas we detected only small sex heterochromatin bodies in the T(W;2)Y-Chu strain and no sex heterochromatin body in the T(W;2)Y-Abe strain. Since adult females of all strains were normal and fertile, we conclude that only extremely limited region, containing the W-Rikishi RAPD sequence of the W chromosome, is required to determine femaleness. Based on a comparison of the normal W-chromosome and 7 translocation and W-deletion strains we present a map of Fem relative to the 12 W-specific RAPD markers."}