Department of Animal Science, North Carolina State University, Raleigh, North Carolina, USA.
Br J Ophthalmol. 2011 Dec;95(12):1749-54. doi: 10.1136/bjophthalmol-2011-300417. Epub 2011 Aug 26.
Truncation mutations in the elongation of very long chain fatty acids-4 (AF277094, MIM #605512) (ELOVL4) gene cause Stargardt-like macular dystrophy type 3 (STGD3). Mice expressing truncated ELOVL4 develop rapid retinal degeneration, but are poor STGD3 models since mice lack a macula. Photoreceptor topography in the pig retina is more similar to that in humans as it includes the cone rich, macula-like area centralis. The authors generated transgenic pigs expressing human disease-causing ELOVL4 mutations to better model the pathobiology of this macular disease.
Pronuclear DNA microinjection and somatic cell nuclear transfer were used to produce transgenic pigs for two different ELOVL4 mutations: the 5 base pair deletion (5 bpdel) and the 270 stop mutation (Y270terEYFP). Retinal transgene expression, morphology and electrophysiology were examined.
The authors obtained four lines of Y270terEYFP and one line of 5 bpdel transgenic animals. Direct fluorescence microscopy indicated that the Y270terEYFP protein is expressed in photoreceptors and mislocalised within the cell. Immunohistochemical examination of transgenic pigs showed photoreceptor loss and disorganised inner and outer segments. Electroretinography demonstrated diminished responses in both transgenic models.
These transgenic pigs provide unique animal models for examining macular degeneration and STGD3 pathogenesis.
伸长酶脂肪酸-4（AF277094，MIM #605512）（ELOVL4）基因截断突变导致斯塔加特样黄斑营养不良 3 型（STGD3）。表达截断 ELOVL4 的小鼠会迅速发生视网膜变性，但由于小鼠缺乏黄斑，因此并不是很好的 STGD3 模型。猪的视网膜感光细胞层结构与人类更为相似，因为它包括富含视锥细胞的黄斑样中央凹区域。作者生成了表达人类致病 ELOVL4 突变的转基因猪，以更好地模拟这种黄斑疾病的病理生物学。
核 DNA 微注射和体细胞核移植用于生产两种不同的 ELOVL4 突变的转基因猪：5 个碱基对缺失（5 bpdel）和 270 个终止突变（Y270terEYFP）。检测视网膜转基因表达、形态和电生理学。
作者获得了 4 条 Y270terEYFP 转基因线和 1 条 5 bpdel 转基因动物。直接荧光显微镜表明，Y270terEYFP 蛋白在感光细胞中表达，并在细胞内定位异常。对转基因猪的免疫组织化学检查显示感光细胞丧失和内、外节排列紊乱。视网膜电图显示两种转基因模型的反应均减弱。
这些转基因猪为研究黄斑变性和 STGD3 发病机制提供了独特的动物模型。
