TRANSGENIC MUTANT WITH DOPAMINERGIC SYSTEM DYSFUNCTION

多巴胺能系统功能障碍的转基因突变体

• 批准号: 3430356
• 负责人: KENNETH W GROSS
• 金额: $ 6.86万
• 依托单位: ROSWELL PARK CANCER INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3430356
• 关键词: degenerative motor system disease; dopamine receptor; gene mutation; genetic library; genetic mapping; genetic markers; genetically modified animals; in situ hybridization; laboratory mouse; molecular cloning; mutant; receptor expression

We have identified an insertional mutant, during the course of making transgenic mice in our laboratory, which exhibits an abnormal circling behavior as the overt phenotype. This transgenic insertional mutant, which we call the chakragati mouse, displays excessive lateralized circling behavior and locomotor hyperactivity by postnatal days 14-16, which persists unattenuated through adolescence and adulthood. the insertional mutation is characterized as autosomal and recessive and is stably transmitted. We hypothesize that integration of the transgene sequences has caused the loss of at least one endogenous gene function resulting in asymmetry and imbalances in the dopaminergic system and the circling phenotype. In the mutants, dopamine D2 receptors are asymmetrically upregulated contralaterally to the preferred direction of circling. Moreover, the potent D2 receptor agonist, quinpirole, was found to potentiate their rate of circling. We have mapped the DNA sequences in the host genome flanking the integration site of the transgene sequences to mouse chromosome 16 and to the homologous region of human chromosome 3. We propose, here, to identify the genetic lesion(s) that resulted in the abnormal circling behavior and asymmetrical D2 receptor upregulation. As part of a general approach, we will carry out a physical characterization of the integration site, then isolate clones across the integration site from the normal genome using the flanking markers as hybridization probes and look for gene coding sequences in these clones. We will also pursue a candidate locus approach as one of our flanking DNA markers appears, in the light of some very recent genetic mapping data, potentially coincident with the dopamine D3 receptor locus. Given that these DNA markers are known to be unlinked to the D2 receptor gene locus and that quinpirole has been reported to have a similarly high affinity for the D3 receptor gene was in fact disrupted during the integration of the transgene sequences and that its expression profile in the insertional mutant is aberrant. We believe that bringing the tools of molecular biology to bear on this insertional mouse mutant will provide novel and specific insights into nigrostriatal systems mediating motor function. This will be important as perturbations in the nigrostriatal pathways of the central dopaminergic system have been implicated to be the basis of several neurobehavioral disorders including Parkinsonism, schizophrenia, and possibly others.

我们已经确定了一个插入突变体，在制造过程中 我们实验室的转基因小鼠，表现出异常的循环 行为表现为显性表型。这个转基因插入突变体， 我们称之为查克拉加蒂鼠标，显示过度偏侧 出生后14-16天的绕圈行为和运动多动， 在整个青春期和成年期都不会减弱。这个 插入突变的特征是常染色体和隐性突变， 传输稳定。我们假设转基因的整合 序列导致至少一个内源基因功能丧失 导致多巴胺能系统的不对称和失衡 循环表型。在突变体中，多巴胺D2受体是 不对称地逆行向上调整到首选方向 在转圈。此外，有效的D2受体激动剂奎比罗是 增强了它们绕圈的速度。我们已经绘制了DNA图谱 宿主基因组中位于整合位点两侧的序列 小鼠16号染色体及其同源区的转基因序列 人类3号染色体。我们建议，在这里，识别 致转圈行为异常的病变(S) 非对称性D2受体上调。作为一般方法的一部分， 我们将对整合地点进行物理特征描述， 然后从正常基因组中分离整合位点上的克隆 利用侧翼标记作为杂交探针寻找基因 这些克隆中的编码序列。我们还将寻找一个候选的轨迹 当我们的侧翼DNA标记之一出现时，根据一些 最新的基因图谱数据，可能与 多巴胺D3受体基因座。鉴于这些DNA标记是已知的 与D2受体基因座无关联，奎比罗已被 据报道，与D3受体基因具有类似高亲和力的是 事实上，在整合转基因序列的过程中中断了 它在插入突变体中的表达谱是异常的。我们 相信利用分子生物学的工具来研究这一点 插入的小鼠突变体将提供新的和特定的见解 黑质纹状体系统调节运动功能。这将是很重要的 作为中央黑质纹状体通路的扰动 多巴胺能系统被认为是几个 神经行为障碍，包括帕金森氏症、精神分裂症和 可能是其他人。