ENHANCED DEVELOPMENT OF THE XIPHOPHORUS MODEL SYSTEM

描述（改编自申请人摘要）：本申请 建议加强开发一种独特的鱼类模型， 致癌的环境和遗传决定因素，即 剑尾鱼基因杂交种。 各种自发性和诱发性肿瘤 是由不同剑尾鱼交配产生的杂交种 （真骨亚纲：花骨鱼科）种。 尽管其中一些混血儿 已经研究了很多年，并提供了一种有用的非哺乳动物 肿瘤发生（主要是黑色素瘤）的模型，大多数只是 初步定性。 因此，该应用程序具有两个中心 目的：化学品（N-甲基-N-亚硝基脲， MNU）诱导的肿瘤模型，以提供MNU诱导的肿瘤模型之间的比较。 肿瘤发生和自发和紫外线（UV）诱导 肿瘤发生（具体目标1和2）;和分子的发展 提高实用性和相关性所需的生物工具和试剂 剑尾鱼杂交作为非哺乳动物疾病模型（具体目标3）。 在 在前两个具体目标中，申请人将使用经典和 分子遗传学方法来分析MNU诱导的肿瘤易感性， 通过两种种间交配产生的回交杂交鱼; X.库奇亚努斯 x（X. 斑叶蝉X. maculatus Jp 163 A × X. couchianus）和X. couchianus x（X. 斑叶蜂X. maculatus Jp 163 B x X. couchianus）。 从这些产生的回交杂种 杂交易患MNU诱导的黑素瘤和视网膜母细胞瘤。 的 在这些杂交中使用的亲本股票携带超过40个固定的多态性 遗传标记，允许申请人进行联合分离 染色体遗传与诱发肿瘤易感性分析。 这些共分离分析将使分配地图位置的基因座 与肿瘤易感性相关和/或直接参与肿瘤易感性。 的 为具体目标3提出的研究将提高实验效用 剑尾鱼遗传杂种作为疾病模型的相关性， 广泛的基因图谱饱和和建立特征分子 图书馆. 地图饱和，加上有待开发的分子工具 本项目的特点是[剑尾鱼酵母人工染色体 (YAC)和粘粒DNA文库]，将为研究人员提供一个 实验系统，能够分离显示遗传的基因， 与任何感兴趣的表型相关。

DESCRIPTION (Adapted from the applicant's abstract): This application proposes to enhance the development of a unique fish model that allows study of both environmental and genetic determinants of carcinogenesis, namely Xiphophorus genetic hybrids. A variety of spontaneous and induced tumors are available in hybrids produced by matings between different Xiphophorus (Teleostei: Poeciliidae) species. Although a few of these hybrids have been studied for many years, and have provided a useful nonmammalian animal model for tumorigenesis (primarily melanoma), most have only been preliminarily characterized. Therefore, this application has two central goals: the experimental development of chemical (N-methyl-N-nitrosourea, MNU)-induced tumor models to provide comparison between MNU-induced tumorigenesis and spontaneous and ultraviolet light (UV)-induced tumorigenesis (Specific Aims 1 and 2); and the development of molecular biological tools and reagents necessary to enhance the utility and relevance of Xiphophorus hybrids as nonmammalian disease models (Specific Aim 3). In the first two Specific Aims, the applicants will use both classical and molecular genetic approaches to analyze MNU-induced tumor susceptibility in backcross hybrid fish produced by two interspecific matings: X. couchianus x (X. maculatus Jp 163A x X. couchianus), and X. couchianus x (X. maculatus Jp 163B x X. couchianus). Backcross hybrids produced from these crosses are predisposed to MNU-induced melanomas and retinoblastomas. The parental stocks utilized in these crosses carry over 40 fixed polymorphic genetic markers, allowing the applicants to perform joint segregation analyses of chromosomal inheritance with induced tumor susceptibility. These cosegregation analyses will enable assignment of map locations to loci associated with, and/or directly involved in, tumor susceptibility. The research proposed for Specific Aim 3 will enhance the experimental utility and relevance of Xiphophorus genetic hybrids as disease models by providing extensive gene map saturation and establishing characterized molecular libraries. Map saturation, coupled with the molecular tools to be developed and characterized in this project [Xiphophorus yeast artificial chromosome (YAC) and cosmid DNA libraries], will provide investigators with an experimental system enabling the isolation of genes showing genetic association with any phenotype of interest.