A rat model for studies of galactosemia

项目摘要 经典型半乳糖血症（CG）是一种潜在的致命性遗传疾病， 半乳糖-1P尿苷酰转移酶（GALT）。而通过新生儿筛查和 半乳糖的立即饮食限制预防或最小化急性和潜在致命的症状 尽管婴儿患有这种疾病，但大多数受影响的儿童仍然会在成长过程中经历一系列使人衰弱的疾病， 认知、行为、运动、女性生殖和其他残疾。这些现象背后的机制 长期并发症仍然未知，阻碍了更有效治疗的发展。之一 限制该领域进展的主要障碍是缺乏CG的哺乳动物遗传模型， 概括了患者结局。具体地说，虽然GALT无效果蝇表现出急性和长期的 与CG相似的并发症，其他小组创建的两只小鼠模型中的每一只都没有。最近我们 应用CRISPR-Cas9基因编辑技术在Sprague-Dawley大鼠中产生GALT的三个突变等位基因。 根据定义，从所有三个不同等位基因中衍生出的单个男性创始人是镶嵌的，至少在 他的生殖细胞，但表现出双侧白内障让人想起未经治疗的病人。在此，我们建议 描述了纯合子GALT缺陷大鼠的急性和长期结果， 饮食半乳糖的存在与不存在。这些研究的结果将建立第一个哺乳动物 GALT缺乏模型，重现了经典半乳糖血症的相关表型，为 未来的研究，以确定疾病的时间和机制，以及一个适合的模型，用于测试新的 候选人干预。

Project Summary Classic galactosemia (CG) is a potentially lethal genetic disease that results from profound loss of galactose-1P uridylyltransferase (GALT). While pre-symptomatic diagnosis by newborn screening and immediate dietary restriction of galactose prevent or minimize the acute and potentially lethal symptoms of disease in infants, a majority of affected children nonetheless grow to experience a constellation of debilitating cognitive, behavioral, motor, female reproductive, and other disabilities. The mechanisms that underlie these long-term complications remain unknown, hindering the development of more effective treatments. One of the major roadblocks limiting progress in the field has been the lack of a mammalian genetic model of CG that recapitulates patient outcomes. Specifically, while a GALT-null fruit fly demonstrates both acute and long-term complications reminiscent of CG, each of two mouse models created by other groups did not. Recently, we applied CRISPR-Cas9 gene editing technology to create three mutant alleles of GALT in Sprague-Dawley rats. The single male founder from whom all three distinct alleles were derived was, by definition, mosaic, at least in his germ cells, but demonstrated bilateral cataracts reminiscent of untreated patients. Here we propose to characterize both the acute and long-term outcomes of homozygous GALT deficient rats reared in the presence versus absence of dietary galactose. The results of these studies will establish the first mammalian model of GALT deficiency that recapitulates relevant phenotypes of classic galactosemia, setting the stage for future studies to define the timing and mechanisms of disease, and an amenable model for testing novel candidate interventions.