| Project/Area Number |
08456034
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
蚕糸・昆虫利用学
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| Research Institution | TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGY |
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Principal Investigator |
OSHIKI Toshikazu TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGY,FACULTY OF AGRICULTURE,PROF., 農学部, 教授 (80015081)
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| Co-Investigator(Kenkyū-buntansha) |
ABE Hiroaki TOKYO UNIVERSITY OF AGROCULTURE AND TECHNOLOGY,FACULTY OF AGRICULTURE,ASSIS PROF, 農学部, 助手 (80222660)
YOKOYAMA Takeshi TOKYO UNIVERSITY OF AGROCULTURE AND TECHNOLOGY,FACULTY OF AGRICULTURE,ASSIS PROF, 農学部, 助手 (20210635)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥7,700,000 (Direct Cost: ¥7,700,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1997: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥4,100,000 (Direct Cost: ¥4,100,000)
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| Keywords | silkwOrm / heterochromatin / W chromosome / retrotransposon / RAPD / Bombyx mori / 性染色体 / クワコ / ゲノム |
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| Research Abstract |
The sex chromosome formulas of Bombyx mori and B.mandarina are ZW (XY) for the female and ZZ for the male. Genomic DNAs were compared between males and females of the silkworm, B.mori and B.mandarina by polymerase chain reaction (PCR) with 700 arbitrary 10-mer primers. Four female-specific RAPDs (W-Kabuki, W-Samurai, W-Kamikaze, and W-Yamato) were found. The four female-specific RAPDs are assumed tobe derived from the W chromosome because the other chromosomes are shared by both sexes. A computer search for deduced amino acid sequences of these four RAPDs revealed that all of them showed homology to previously reported amino acid sequences encoded in known retrotransposable elements from various organisms. To further analyze the W chromosome of B.mori we constructed a genomic DNA lambda phage library and picked the lambda phage clone containing the W-Kabuki RAPD sequence by using a PCR strategy. We then sequenced the 18.1-kb DNA inset. Based on a computer search, we determined that this 18.1-kb insertional DNA is composed primarily of clusters of three retrotransposable elements, one retroposon, and one functionally unknown insertion. Each element, namely a non-LTR retrotransposable element BMC1, a retroposon Bm1, functionally unknown inserted DNA, and a novel copia-like LTR retrotransposable element, Yakozuna, was inserted into a novel gypsy-Ty3-like LTR retrotransposable element, Kabuki. Yokozuna contains a single long open reading frame (ORE) and the whole deduced amino acid sequence of ORF reveals strong homology with copia of Drosophila. This BMC1 is 5091 bp and contains a 5'untranslated region, two intact ORFs, and 3'-UTR which terminates in a poly (A) tail. In B.mori and B.mandarina many retrotransposable elements and derivatives might be accumulated in W chromosome than in autosomes or Z chromosome.
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