EMBRYOLOGIC CONSEQUENCES OF TRISOMY 16 IN MICE

16 三体对小鼠的胚胎学影响

基本信息

批准号：
3317599
负责人：
Mary L Oster-Granite
金额：
$ 14.99万
依托单位：
UNIVERSITY OF CALIFORNIA RIVERSIDE
依托单位国家：
美国
项目类别：
财政年份：
1984
资助国家：
美国
起止时间：
1984-07-01 至 1996-11-30
项目状态：
已结题

项目摘要

The long term objective of this research program remains the analysis of the developmental consequences of overexpression of genes triplicated in the trisomy 16 (Ts16) mouse. Two such genes located on mouse chromosome 16 (MMU 16) encode preprosomatostatin (Smst) and a transcription factor, pit-1 (dwarf, dw). Although dwarf and Smst are not the same gene, dwarf mice express elevated levels of preprosomatostatin in various regions of their brains, and have premature loss of Smst expressing cells in regions of their hypothalami. The overall aims of this proposal are to determine whether the products of the Smst gene function to modulate growth and/or development and survival of neurons and glia in the early nervous system in normal, Ts16, and dwarf mice and thus to contribute to the structural and neurochemical deficits observed in Ts16 mice and dwarf mice. to dissect the neurobiological effects of excess somatostatin expression independent of the effects that arise from triplication of the dwarf locus in Ts16 mice, mice transgenic for the endogenous Smst gene will also be studied. Five separate lines of such Smst transgenic (SmstTg) mice have been developed, and differ in genetic background, levels of overexpression, and phenotype. Three of these SmstTg lines have been well characterized and exhibit both intrauterine and postnatal growth alterations and variable levels of overexpression of Smst in different regions of their brains. One line, SmstTg13, exhibits intrauterine and postnatal growth retardation, excess Smst expression, increased levels of proSRIF derived peptides, and cholinergic deficits, reminiscent of the phenotype of the dwarf mouse. The first specific aim is to characterize Smst expression in early brain development in normal, Ts16, Smst transgenic, and dwarf mice, and to correlate such expression with parameters of growth during the prenatal and postnatal period. The second specific aim is to examine the generation and survival of cholinergic neuron populations in the brain and spinal cord of these groups of mice relative to levels of Smst expression. The third specific aim is to analyze particular behavioral and neurochemical changes which occur in normal, SmstTg, and dwarf mice during the postnatal period, particularly changes which occur in spontaneous activity and in the parameters of the cholinergic system. Methods for RNA and DNA analysis and quantification, polymerase chain reaction and reverse transcription polymerase chain reaction, in situ hybridization, radioimmunoassay, immunocytochemistry, single pulse and cumulative cell birthdating, and light and electron microscopy will be used in these studies. Together, these studies will help us to obtain a greater understanding of the role of somatostatin in normal and abnormal development of the nervous system and the relationship between smst expression and the expression of the transcription factor, pit-1.

该研究计划的长期目标仍然是分析基因过度表达的发育后果三倍 16 三体 (Ts16) 小鼠。两个这样的基因位于小鼠染色体上 16 (MMU 16) 编码前促生长素抑制素 (Smst) 和转录因子， pit-1（矮人，dw）。虽然dwarf和Smst不是同一个基因，但dwarf 小鼠各区域的前促生长素抑制素表达水平升高他们的大脑，并且某些区域的 Smst 表达细胞过早丧失他们的下丘脑。该提案的总体目标是确定 Smst 基因的产物是否具有调节生长和/或早期神经系统中神经元和神经胶质细胞的发育和存活在正常、Ts16 和侏儒小鼠中，从而有助于结构在 Ts16 小鼠和侏儒小鼠中观察到神经化学缺陷。到剖析过度生长抑素表达的神经生物学效应与矮星三重倍增所产生的影响无关 Ts16 小鼠中，内源性 Smst 基因转基因小鼠将也有待研究。此类 Smst 转基因 (SmstTg) 的五个独立品系小鼠已经被培育出来，并且遗传背景、水平不同过度表达和表型。其中三个 SmstTg 线已特征明确并表现出宫内和产后生长不同组织中 Smst 过度表达的改变和可变水平他们的大脑区域。一根线，SmstTg13，展示了宫内和出生后生长迟缓、Smst 表达过多、水平升高 proSRIF 衍生肽和胆碱能缺陷，让人想起侏儒小鼠的表型。第一个具体目标是表征早期大脑中的 Smst 表达正常、Ts16、Smst 转基因和侏儒小鼠的发育，并将这种表达与产前生长参数相关联和产后时期。第二个具体目标是检查大脑中胆碱能神经元群的产生和存活这些组小鼠的脊髓和脊髓与 Smst 水平的关系表达。第三个具体目标是分析特定行为正常小鼠、SmstTg 小鼠和侏儒小鼠中发生的神经化学变化在产后期间，特别是发生的变化自发活动和胆碱能系统的参数。 RNA 和 DNA 分析和定量方法，聚合酶链原位反应和逆转录聚合酶链反应杂交、放射免疫分析、免疫细胞化学、单脉冲和累积细胞生日，光学和电子显微镜将在这些研究中使用。总之，这些研究将帮助我们获得更好地了解生长抑素在正常和神经系统发育异常及其关系 smst 表达和转录因子pit-1 的表达。