Kômoto N, Sezutsu H, Yukuhiro K, Banno Y, Fujii H
Insect Genetics and Evolution Department, National Institute of Agrobiological Sciences, Ibaraki, Japan.
Insect Biochem Mol Biol. 2003 Apr;33(4):417-27. doi: 10.1016/s0965-1748(03)00006-7.
Normal silkworms (Bombyx mori) have opaque larval skin due to uric acid accumulation in the epidermis while a mutant, og, is translucent owing to a deficiency in xanthine dehydrogenase (XDH), which synthesizes uric acid. Molybdenum cofactor (MoCo) sulfurase is responsible for XDH activation in various organisms. A silkworm MoCo sulfurase gene was cloned and found to be on the og locus, whose mutant alleles, og(k) and og(t), show premature stop codons, proving that og is the MoCo sulfurase gene. It was observed that a miniature inverted-repeat transposable element (MITE), named Organdy, when inserted in an og(t) mutant allele exon, causes unstable splicing of a downstream intron leading to incomplete open reading frames.
正常家蚕（Bombyx mori）由于尿酸在表皮中积累，幼虫皮肤不透明，而一个名为og的突变体由于合成尿酸的黄嘌呤脱氢酶（XDH）缺乏而呈半透明。钼辅因子（MoCo）硫化酶负责多种生物体中XDH的激活。克隆了一个家蚕MoCo硫化酶基因，发现它位于og位点上，其突变等位基因og(k)和og(t)显示出提前终止密码子，证明og就是MoCo硫化酶基因。据观察，一种名为Organdy的微型反向重复转座元件插入og(t)突变等位基因外显子时，会导致下游内含子的不稳定剪接，从而导致开放阅读框不完整。
