期刊
INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY
卷 43, 期 7, 页码 594-600出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ibmb.2013.03.009
关键词
Melanisation; Sclerotisation; Cuticle; Dopamine; Maternal transmission; Transposable element
资金
- JSPS
- KAKENHI [22128004, 24658048]
- Grants-in-Aid for Scientific Research [22128004, 24658048] Funding Source: KAKEN
Albino (al) is a lethal mutant of Bombyx mori that exhibits a colourless cuticle after the first ecdysis and dies without feeding on mulberry. Previous studies have indicated that sclerotisation was insufficient because of defective phenylalanine and tyrosine metabolism in albino larvae. However, the genetic mechanism underlying the albino phenotype has not been determined. Dopamine plays a central role in insect cuticle colouration and sclerotisation. The pathway for dopamine biosynthesis from phenylalanine involves phenylalanine hydroxylase (PAH; EC 1.14.16.1) and tyrosine hydroxylase (TH; EC 1.14.16.2). Tetrahydrobiopterin (BH4) is an essential cofactor of aromatic amino acid hydroxylases, including PAH and TH. Thus, BH4 is indispensable for cuticle colouration and sclerotisation. Here we report on identifying mutations in the gene that encodes for the Bombyx homolog of 6-pyruvoyl-tetrahydropterin synthase (PTS) which is involved in the biosynthesis of BH4, in 2 strains with different at alleles. In strain a60 (al), a transposable element was inserted in exon 2 of BmPTS. In strain a61 (al(2)), an 11-bp deletion was identified in the exon 2 region of BmPTS. After oral administration of BH4 to the al(2) larvae, the survival rate was effectively increased and the larval integument was pigmented. These results indicated that BmPTS was responsible for the albino mutants of B. mori. We conclude that (i) a mutation in BmPTS leads to an insufficient supply of BH4 and results in defective dopamine biosynthesis and (ii) lack of dopamine results in cuticle colouration and sclerotisation failure. Lemon (tern) is a BH4-deficient mutant. It has been reported that de novo synthesis of zygotic BH4 was indispensable for viability of the embryo in eggs laid by tern (lemllem(l)) females. We found that lem/lem, al(2)/al(2) larvae produced by tern (lem/lem) females were viable during the first instar stage, suggesting that al(2)/al(2) embryo could synthesis BH4 by using maternally transmitted BmPTS. (C) 2013 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据