MOLECULAR GENETICS OF BMP2 AND 4--FOP CANDIDATE GENES

骨骼的胚胎发生和再生是复杂的 发育事件依赖于软骨内膜的成功诱导 成骨作用。然而，人们对骨骼的基因控制知之甚少。 归纳法。最近克隆了七种骨形态发生的cDNA 蛋白质(BMP1-7)，其中六个(BMP2-7)是一个古老的和 参与发育的高度保守的分子家族 胚胎模式形成的调控。表达的蛋白质来自两个 相关重组克隆(BMP2&4)具有诱导BMP2和BMP4表达的能力。 异位软骨内成骨的完整发育程序 在组织结构上与在极端 罕见遗传性进行性骨化性纤维发育不良(FOP)。FOP是 一种渐进性致残性结缔组织疾病，其特征是 先天性足趾胚芽原骨畸形及 关节软骨内成骨的时空无序诱导 异位网站。 为我们的长期目标提供重点的两个相关假设是 提出：第一，人骨形成蛋白2&的分子结构和功能。 4个基因将提供对基因调控的基本见解 人软骨内骨诱导和形态形成；第二，BMP2 &4是FOP的候选基因，其分子结构 这些基因的调控区域可能在慢性阻塞性肺疾病患者中异常 FOP。 为了解决这些假设，我们打算：1.分离基因组克隆 BMP2和BMP4使用部分长度的cDNA作为探针。2.确定 BMP2和BMP4的转录起始点来确定RNA编码 这些基因的区域。3.表征启动子和其他顺式- DNA序列分析BMP2和BMP4的调控区。4.定义 BMP2&4在启动子/增强子表达中的功能调控单元 化验系统。5.利用RFLP技术进行FOP DNA突变筛查 用于BMP2和BMP4基因的增加、缺失或重排 基因组探针(1)。 人类的分子组织与调控分析 BMP2和BMP4基因将促进阐明基础的长期目标 正常和无序骨诱导的机制及其设计 多种疾病的合理分子诊断和治疗策略 人类骨骼的发育障碍。

The embryogenesis and regeneration of the skeleton are complex developmental events dependent on the successful induction of endochondral osteogenesis. Little is known, however, about the genetic control of bone induction. cDNAs have recently been cloned for seven bone morphogenetic proteins (BMP1-7), six of which (BMP2-7) are members of an ancient and highly conserved family of molecules involved in the developmental regulation of embryonic pattern formation. Proteins expressed from two related recombinant clones (BMP2 & 4) possess the capacity to induce the entire developmental program of endochondral osteogenesis in an ectopic site in a pattern histologically identical to that seen in the extremely rare genetic disorder Fibrodysplasia Ossificans Progressiva (FOP). FOP is a progressively disabling connective tissue disorder characterized by congenital malformations of the blastemal anlage of the toes and disordered temporal and spatial induction of endochondral osteogenesis at ectopic sites. Two related hypotheses that provide the focus for our long-term goals are proposed: first, the molecular structure and function of the human BMP2 & 4 genes will provide fundamental insight into the genetic regulation of endochondral bone induction and pattern formation in humans; second, BMP2 & 4 are candidate genes for FOP, and the molecular structure of the regulatory control regions of these genes may be abnormal in patients with FOP. To address these hypotheses, we intend to: 1. Isolate genomic clones for BMP2 & 4 using partial length cDNAs as probes. 2. Identify the transcription initiation sites of BMP2 and BMP4 to define the RNA-coding regions of these genes. 3. Characterize the promoter and other cis- regulatory regions of BMP2 & 4 by DNA sequence analysis. 4. Define the functional control unit of BMP2 & 4 in a promoter/enhancer expression assay system. 5. Perform mutational screening of FOP DNA by RFLP analysis for additions, deletions, or rearrangements in BMP2 & 4 genes using genomic probes (obtained in 1). Analysis of the molecular organization and regulatory control of the human BMP2 & 4 genes will foster the long-term goals of elucidating basic mechanisms of normal and disordered bone induction, and of designing rational molecular diagnostic and treatment strategies for a wide range of developmental disorders of the skeleton in humans.