| RRC ID |
6088
|
| 著者 |
Liu C, Yamamoto K, Cheng TC, Kadono-Okuda K, Narukawa J, Liu SP, Han Y, Futahashi R, Kidokoro K, Noda H, Kobayashi I, Tamura T, Ohnuma A, Banno Y, Dai FY, Xiang ZH, Goldsmith MR, Mita K, Xia QY.
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| タイトル |
Repression of tyrosine hydroxylase is responsible for the sex-linked chocolate mutation of the silkworm, Bombyx mori.
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| ジャーナル |
Proc Natl Acad Sci U S A
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| Abstract |
Pigmentation patterning has long interested biologists, integrating topics in ecology, development, genetics, and physiology. Wild-type neonatal larvae of the silkworm, Bombyx mori, are completely black. By contrast, the epidermis and head of larvae of the homozygous recessive sex-linked chocolate (sch) mutant are reddish brown. When incubated at 30 degrees C, mutants with the sch allele fail to hatch; moreover, homozygous mutants carrying the allele sch lethal (sch(l)) do not hatch even at room temperature (25 degrees C). By positional cloning, we narrowed a region containing sch to 239,622 bp on chromosome 1 using 4,501 backcross (BC1) individuals. Based on expression analyses, the best sch candidate gene was shown to be tyrosine hydroxylase (BmTh). BmTh coding sequences were identical among sch, sch(l), and wild-type. However, in sch the approximately 70-kb sequence was replaced with approximately 4.6 kb of a Tc1-mariner type transposon located approximately 6 kb upstream of BmTh, and in sch(l), a large fragment of an L1Bm retrotransposon was inserted just in front of the transcription start site of BmTh. In both cases, we observed a drastic reduction of BmTh expression. Use of RNAi with BmTh prevented pigmentation and hatching, and feeding of a tyrosine hydroxylase inhibitor also suppressed larval pigmentation in the wild-type strain, pnd(+) and in a pS (black-striped) heterozygote. Feeding L-dopa to sch neonate larvae rescued the mutant phenotype from chocolate to black. Our results indicate the BmTh gene is responsible for the sch mutation, which plays an important role in melanin synthesis producing neonatal larval color.
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| 巻・号 |
107(29)
|
| ページ |
12980-5
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| 公開日 |
2010-7-20
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| DOI |
10.1073/pnas.1001725107
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| PII |
1001725107
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| 解説 |
sch(赤蟻）の原因遺伝子はBmTHである。BmThはチロシン水酸化酵素をコードする。sch系統やschl系統ではBmTHの発現量が低下している。これは、sch系統のBmTH上流6kb～70kbの領域が欠失しているため、schl系統のBmTHの転写開始点近傍にnon-LTR型のトランスポゾンL1Bmが挿入されているためだと推定されている。
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| PMID |
20615980
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| PMC |
PMC2919899
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| MeSH |
Animals
Bombyx / enzymology*
Bombyx / genetics*
Chromosome Mapping
Genes, Insect / genetics*
Genetic Linkage
Genome / genetics
Larva
Mutation / genetics*
Phenotype
Pigmentation / genetics*
Reproducibility of Results
Sex Characteristics*
Tyrosine 3-Monooxygenase / metabolism*
|
| IF |
9.412
|
| 引用数 |
58
|
|
WOS 分野
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GENETICS & HEREDITY
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| リソース情報 |
| カイコ |
pS mutant |
