CLONING THE X-LINKED RETINITIS PIGMENTOSA GENES

X连锁视网膜色素变性是遗传性视网膜病变中最严重的一种。 人类致盲的主要原因，但其生物化学基础尚不清楚。 为人所知。最近的连锁数据表明存在两个不同的基因座， 都定位于X染色体的近端短臂：一个在 XP(RP3)和另一个更近端与DXS7连锁的(RP2)。这项研究 该提案旨在克隆和鉴定RP3基因，并确定 进一步研究了RP2基因座的染色体定位。要分离出 RP3基因，新获得的基因组克隆 将进一步分析CGD基因和JBB基因，以识别保守的 指示包含外显子的序列的序列，并检测 无血缘关系的男性WD患者DNA图谱中的微缺失或重排 用Southern印迹分析或脉冲场凝胶电泳法进行XRP分析。 定位在RP3基因座附近或位于RP3基因座内的其他克隆将是iso- 通过从最近的侧翼双向染色体行走来延迟的 噬菌体文库中的标记及对已获得的酵母的分析 包含此序列的人工染色体(YAC)克隆 区域。 检测到保守序列的克隆将用于分离 候选RP3 cDNA将进一步由Northern 分析和测序。一旦找到候选序列， 未来的努力将集中在确定RP3的突变上 基因座，阐明基因的结构组织和发育 研究RP3细胞和生化特性的试剂 蛋白。为了更准确地定位RP2基因座，需要详细的长距离 连接DXS7和DXS255之间区域的限制图，以及 将开发识别HTF岛屿，目的是识别 含有RP2基因的限制性片段。

X-linked Retinitis Pigmentosa is one of the most sever e of the hered- itary causes of blindness in man, yet its biochemical basis remains un- known. Recent linkage data indicate the existence of two distinct loci, both regionalized to the proximal short arm of the X chromosome: one at Xp (RP3) and the other more proximal linked to DXS7 (RP2). This research proposal aims to clone and characterize the gene for RP3 and define further the chromosomal localization of the RP2 locus. To isolate the RP3 gene, genomic clones recently obtained from the region between the CGD locus and JBB will be analyzed further in order to identify conserved sequences indicative of exon containing sequences and to detect either microdeletions or rearrangements in DNA panels of unrelated males with XRP by either Southern blot analysis or pulse field gel electrophoresis. Additional clones that map close to or within the RP3 locus will be iso- lated by bidirectional chromosomal walking from the nearest flanking markers in phage libraries and by analysis of already obtained Yeast Artificial Chromosome (YAC) clones that contain sequences from this region. Clones that detect conserved sequences will be used to isolate candidate RP3 cDNAs which will be further characterized by Northern analysis and sequencing. Once a candidate sequence had been found, future efforts will be targeted towards identifying mutations at the RP3 locus, elucidating the structural organization of the gene and developing reagents to study the cellular and biochemical properties of the RP3 protein. To localize more precisely the RP2 locus a detailed long range restriction map that will link up regions between DXS7 and DXS255 and identify HTF islands will be developed with the aim of identifying the restriction fragment that contains the RP2 gene.