1994 Fiscal Year Final Research Report Summary
Analysis of chromatin structure and gene function of chicken sex chromosomes
| Project/Area Number |
05454068
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
応用微生物学・応用生物化学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
MIZUNO Shigeki Tohoku University, Dept. Applied Biol. Chem., Professor, 農学部, 教授 (90112903)
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| Co-Investigator(Kenkyū-buntansha) |
HARATA Masahiko Tohoku University, Dept. Applied Biol. Chem., Assistant, 農学部, 助手 (70218642)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Chicken / Sex Chromosome / W Chromosome / Z Chromosome / Heterochromatin / Sex Chromosome-speicific Library / Genomic Library / Immunoglobulin Superfamily |
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| Research Abstract |
Constitution of chicken sex chromosomes is ZW for female and ZZ for male. About 2/3 of the W chromosome and a terminal region of the Z chromosome are heterochromatic. Two W-chromosome-specific repetitive DNA sequences, XhoI family and EcoRI family, are major constituents of the W heterochromatin, but nature of the Z-terminal heterochromatin is unknown. In this study, 1) a genomic clone pCHZTH8 containing about 13kb genomic fragment was obtained from the female chicken genomic library. Fluorescence in situ hybridization (FISH), Southern blot hybridization and nucleotide sequencing revealed that this cloned sequence was a part of the macrosatellite DNA localized in the Z-terminal heterochromatin and that most part of this sequence was specific to the genus Gallus. 2) Although about 20 phenotypes are mapped to the Z chromosome, molecular-level information has not been available. We demonstrated by cDNA cloning and FISH that ZOV3 (a gene belonging to the immunoglobulin superfamily) and IREBP (chicken homolog of iron responsive element binding protein) were localized on different arms of the Z chromosome. 3) Except for the above two repetitive families, W chromosome-specific DNA sequences are unknown. We constructed a W chromosome-specific genomic library by applying laser microdissection and random PCR amplification. Two clones containing W-specific non-repetitive sequences (CW01 and CW50) were obtained. A female chicken genomic library was screened with CW01 and CW50, and genomic clones convering two genomic regions of about 25-kb each, containing the CW01 and CW50 sequences, respectively, were obtained.
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