Application of Genetics and Physiological Genomics to Dissect Resistance to T1D

1型糖尿病(T1D)是一种典型的器官特异性自身免疫性内分泌疾病，导致终生依赖每日注射胰岛素。分子遗传学方法已经确定了人类、小鼠和大鼠基因组中在1型糖尿病(T1D)易感性中发挥作用的区域。虽然主要组织相容性复合体(MHC)，相当于人类白细胞抗原(HL A)，是导致T1D易感性的主要基因，但还有一组单独的基因与易感性和最终器官损害有关。我们一直在研究导致BBDP大鼠T1D的遗传因素，BBDP大鼠是一种并发淋巴细胞减少的自发性疾病模型。我们已经确定了五个基因座的位置 T1D：Iddm2/LYP，Iddm1/Mhc，Iddm3，Iddm19，第4染色体第五位点(Iddm4？)。鉴于Ian5突变被确定为导致Iddm2/LYP的基因，我们现在专注于确定在BB大鼠的T1D中起作用的其他因素。我们的作图研究已经确定了除MHC以外的四个糖尿病致病基因，项目3与项目1密切合作。项目3的重点是为三个额外因素产生共生和衍生的同源菌株，包括Iddm3、Iddm19和位于染色体4靠近Ian5的易感基因(项目1)，并使用基因表达谱、比较基因组学和序列分析来评估这些新模型在T1D中的作用。此外，我们正在开发一种技术，以敲除老鼠体内的基因 定位克隆基因的验证。具体地说，我们将：1.继续IddM3的位置克隆努力，以确定有助于抵抗自身免疫性糖尿病的序列变体。 2.跟踪15号染色体上的第二个耐药因子。3.利用新型的70聚体寡核苷酸和基因芯片平台，评估在BB大鼠中发现的糖尿病致病因子影响的基因和途径。4.建立ENU诱导的大鼠基因敲除株，以验证BB大鼠自身免疫性糖尿病相关基因。

Type 1 diabetes (T1D) is one of the prototypical organ-specific autoimmune endocrinopathies that results in life-long dependency on daily insulin injection. Molecular genetic approaches have identified regions of the human, mouse, rat genomes that play a role in susceptibility to Type 1 Diabetes (T1D). While the major histocompatibility complex (MHC), the equivalent of the human leukocyte antigen (HLA), is the major locus responsible for susceptibility to T1D, there is a separate set of genes that contribute to susceptibility and end organ damage. We have been studying the genetic factors contributing to T1D in the BBDP rat, a model of spontaneous disease concurrent with lymphopenia. We have identified the location of five loci involved in T1D: Iddm2/lyp, lddm1/MHC, Iddm3, Iddm19, and a fifth locus on chromosome 4 (Iddm4?). Given the identification of the Ian5 mutation as the gene responsible for Iddm2/lyp, we now focus on the identification of the additional factors playing a role in T1D in the BB rat. Our mapping studies have identified four diabetogenic loci in addition to the MHC, which Projects 3 specifically addresses, in close collaboration with Project 1. The focus of Project 3 is to generate consomic and derived congenic strains for three additional factors, including Iddm3, Iddm19, and the susceptibility locus on chromosome 4 nearby Ian5 (Project 1) and to evaluate these new models for their role in T1D using gene expression profiling, comparative genomics, and sequence analysis. Furthermore, we are developing the technology to knock genes out in the rat for validation of positionally cloned genes. Specifically we will: 1. Continue positional cloning efforts for Iddm3 to identify sequence variants contributing to resistance to autoimmune diabetes. 2. Follow up a second resistance factor on chromosome 15. 3. Use novel 70-mer oligonucleotide and cDNA microarray platforms to evaluate genes and pathways affected by the diabetogenic factors identified in the BB rat. 4. Generate rat ENU-induced knockout strains to validate genes involved in autoimmune diabetes in the BB rat.