Hyodo-Taguchi Y, Winkler C, Kurihara Y, Schartl A, Schartl M
National Institute of Radiological Sciences, Division of Biology, Chiba, Japan.
Mech Dev. 1997 Nov;68(1-2):27-35. doi: 10.1016/s0925-4773(97)00128-7.
Mutations of the tyrosinase gene are one common cause of a similar phenotype in all vertebrates, known as albinism. In an attempt to contribute to an understanding of the genetic hierarchy governing the development of pigmentation, we have used a mouse tyrosinase minigene under the control of its 5.2 kb upstream promoter region to rescue two different albino mutations in the medakafish, Oryzias latipes. Around hatching stages an almost perfect phenocopy of the wildtype pigmentation was obtained. Subsequent ectopic melanin overproduction indicated a possible incompatibility of the heterologous mouse promoter for stable expression during the entire ontogenesis. Like in some tyrosinase transgenic mouse lines a strong variegation effect was observed. The transgene-mediated pigmentation phenotype was obtained up to the eighth offspring generation. The phenotypic effects of the tyrosinase transgene in different albino mutant strains places the i3-locus upstream and the b-locus downstream of the tyrosinase locus i1 in the genetic hierarchy leading to wildtype pigmentation.
酪氨酸酶基因突变是所有脊椎动物中类似表型的一个常见原因，即白化病。为了有助于理解控制色素沉着发育的遗传层次结构，我们使用了一个在其5.2 kb上游启动子区域控制下的小鼠酪氨酸酶小基因，来拯救青鳉（Oryzias latipes）中的两种不同白化突变。在孵化阶段左右，获得了几乎与野生型色素沉着完全一致的拟表型。随后的异位黑色素过度产生表明，异源小鼠启动子在整个个体发育过程中可能无法稳定表达。就像在一些酪氨酸酶转基因小鼠品系中一样，观察到了强烈的斑驳效应。转基因介导的色素沉着表型一直持续到第八代后代。酪氨酸酶转基因在不同白化突变菌株中的表型效应表明，在导致野生型色素沉着的遗传层次结构中，i3位点在酪氨酸酶基因座i1的上游，b位点在其下游。
