ISOLATION & CHARACTERIZATION OF HRG4, A NEW RETINAL GENE

描述（改编自申请人摘要）：申请人已 分离到一个新的视网膜特异性基因，称为HRG 4（人视网膜 基因4）。申请人已经表明HRG 4（1）定位于染色体17，（2） 在其他物种中是保守的，（3）不匹配任何已知序列， (4)在光感受器中特异性表达，特别是在 差异化国家常染色体显性视网膜炎 最近，南非一个家族中的ADRP被定位到 染色体17 p和Leber先天性黑蒙的初步定位 17 q的突变导致申请人假设HRG 4中的突变可以 导致视网膜退化。长期目标是分离新人类 视网膜基因，如HRG 4，以提供进一步我们的机会， 了解视网膜生物学和功能，并作为候选人 人类视网膜退化的基因。 为实现这一目标，提出了以下目标：（1）确定 HRG 4基因产物的功能方面，申请人将：（a） 表达蛋白质，制备抗体，并将HRG 4免疫定位于 光学和电子显微镜水平，（B）确定其发育 表达以及其日常波动或运动， 大鼠免疫细胞化学和原位杂交，和（c）探测其 在大鼠和大鼠视网膜原位视网膜电图水平上的功能 通过使用抗体和反义分子的外植体;（2） 完成HRG 4在核苷酸水平的分析，申请人 将：（a）确定HRG 4是否是基因家族的成员，（B）克隆 并表征该基因，以及（c）克隆并表征大鼠同源物 cDNA用作特异性功能探针（用于目的基因的某些实验） 1）;和（3）分析HRG 4基因作为人类的候选基因， 视网膜变性，申请人将：（a）筛选缺失， 使用来自患者的DNA的重排或更细微的突变，（B） 进行连锁分析和筛选正常对照对任何 在患者中发现的突变，和（c）亚定位HRG 4基因在 17号染色体。

DESCRIPTION (Adapted from applicant's abstract): The applicant has isolated a new retina-specific gene which is termed HRG4 (human retinal gene 4). The applicant has shown that HRG4 (1) maps to chromosome 17, (2) is conserved in other species, (3) does not match any known sequence, and (4) is expressed specifically in photoreceptors, particularly in the differentiated state. The fact that autosomal dominant retinitis pigmentosa (ADRP) in a South African family was recently mapped to chromosome 17p and Leber's congenital amaurosis was preliminarily mapped to 17q led the applicant to hypothesize that mutations in HRG4 could cause retina degenerations. The long-range goal is to isolate new human retinal genes such as HRG4 to provide the opportunity to further our understanding of retinal biology and function and to serve as candidate genes for human retina degenerations. To achieve this goal the following aims are proposed: (1) to determine functional aspects of the HRG4 gene product, the applicant will: (a) express the protein, prepare antibodies and immunolocalize HRG4 at the light and electron microscopic levels, (b) determine its developmental expression as well as its daily fluctuations or movements by immunocytochemistry and in situ hybridization in rats, and (c) probe its function at the electroretinogram level in situ in rats and rat retina explants by the use of antibodies and antisense molecules; (2) to complete the analysis of HRG4 at the nucleotide level, the applicant will: (a) determine whether HRG4 is a member of a gene family, (b) clone and characterize the gene, and (c) clone and characterize a rat homologue cDNA for use as a specific functional probe (for some experiments in aim 1); and (3) to analyze the HRG4 gene as a candidate gene for human retinal degenerations, the applicant will: (a) screen for deletions, rearrangements or more subtle mutations using DNA from patients, (b) perform linkage analysis and screening of normal controls on any mutations found in the patients, and (c) sublocalize the HRG4 gene on chromosome 17.