ISOLATION & CHARACTERIZATION OF HRG4, A NEW RETINAL GENE

描述(改编自申请人摘要)：申请人有 分离到一个新的视网膜特异基因，命名为HRG4(人视网膜 基因4)。申请人已证明HRG4(1)定位于17号染色体，(2) 在其他物种中保守，(3)与任何已知序列不匹配，以及 (4)在光感受器中特异表达，特别是在 分化状态。常染色体显性视网膜炎 一个南非家庭的色素(Adrp)最近被定位为 染色体17p与Leber‘s先天性黑色素的初步定位 导致申请人假设HRG4的突变可以 导致视网膜退化。长期目标是隔离新人类 视网膜基因，如HRG4，提供了进一步发展我们 了解视网膜的生物学和功能，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 关于HRG4基因产物的功能方面，申请人将：(A) 表达该蛋白，制备抗体并免疫定位HRG4在 光镜和电子显微镜水平，(B)决定其发育 表达及其每日的波动或运动 免疫细胞化学和原位杂交，以及(C)探讨其 大鼠和大鼠视网膜在视网膜电信号水平的原位功能 通过使用抗体和反义分子的外植体； 在核苷酸水平上完成HRG4的分析，申请人 将：(A)确定HRG4是否是基因家族的成员，(B)克隆 并对该基因进行鉴定，以及(C)克隆并鉴定一种大鼠同源物 用作特定功能探针的cDNAs(用于AIM的某些实验 1)；(3)分析HRG4基因作为人类候选基因 视网膜变性，申请人将：(A)筛查缺失， 使用患者DNA进行重排或更细微的突变，(B) 对任何一个正常对照进行连锁分析和筛查 在患者中发现突变，以及(C)使HRG4基因亚区块化。 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.