GENETIC ANALYSIS--DYSERYTHROPOIETIC ANEMIA IN ZEBRAFISH

描述（改编自应用程序） 造血是由多能干细胞引起的一系列事件 终末分化的血细胞。此信号的缺陷 级联反应可导致红细胞生成不良，并揭示重要的分子 事件和红细胞分化的基本过程。 红细胞生成不良在各种先天性和后天性 表明骨髓应激的贫血，如先天性 红细胞生成不良性贫血（CDA）、骨髓增生异常综合征、白血病 巨幼细胞性贫血，HIV感染，骨髓恢复 移植和溶血性贫血。对这一精髓的充分理解 应激反应有待鉴定参与这一级联反应的基因。 事件为了实现这一理解，我们建议采取一种方法， 使用斑马鱼（Danio rerio）作为遗传模型系统。将合并的 斑马鱼的遗传和胚胎学优势使其成为理想的模型 系统来研究造血的发育事件。近45 斑马鱼的突变，代表约25个基因，有缺陷， 造血作用已被确认。这些斑马鱼血液突变中的一种 视网膜病是一种常染色体隐性遗传疾病， 受精后3天出现严重贫血。使用分子标记， 组织学特征，我们表明骨髓和淋巴谱系是 不受这种突变的影响。存活至成年的视网膜突变体 在多染性成红细胞中显示完全成熟停滞 具有大百分比细胞具有双叶核的阶段。撞击 retsina突变型成红细胞组织学特征最能使人联想到 来自患有红细胞生成不良性贫血的人类患者的涂片，特别是 HEMPAS（遗传性成红细胞多核性，酸化阳性） 血清，CDA 2型）。这项建议的具体目的是克隆 retsina基因在斑马鱼中的定位克隆策略。我在地图上 具有紧密连锁标记的retsina基因座（基于10/1380的0.7cM 减数分裂重组体）。候选基因已被分离和排除， retsina进行连锁分析。遗传连锁的YAC、BAC和PAC克隆 已经被分离出来，并进行了染色体漫步。后 在斑马鱼中分离retsina基因，它的人类同源物将是 在患有CDA和其他红细胞生成障碍的人类患者中进行了克隆和检查 贫血人类基因的分离将由 在斑马鱼和人类基因组的这一区域内存在广泛的同线性。 retsina基因的克隆将进一步加深我们对 正常红细胞分化和 CDA中的红细胞生成障碍，骨髓发育不良。

DESCRIPTION (adapted from the application) Hematopoiesis is a cascade of events leading from a pluripotent stem cell to terminally differentiated blood cells. Defects in this signaling cascade can results in dyserythropoiesis and reveal important molecular events and underlying processes in erythrocyte differentiation. Dyserythropoiesis is observed in a variety of congenital and acquired anemias indicative of bone marrow stress, such as congenital dyserythropoietic anemias (CDA), myelodysplastic syndromes, leukemia megaloblastic anemia, HIV infection, recovery from bone marrow transplantation, and hemolytic anemia. A full understanding of this marrow stress response awaits identification of genes involved in this cascade of events. To achieve this understanding, we propose to take an approach using zebrafish (Danio rerio) as a genetic model system. The combined genetic and embryological advantages of zebrafish make it an ideal model system to study the developmental events of hematopoiesis. Nearly 45 zebrafish mutations, representing about 25 genes, defective in hematopoiesis have been identified. One of these zebrafish blood mutations called retsina is an autosomal recessive disorder which results in a profound anemia at 3 days post-fertilization. Using molecular markers and histologic features, we showed that myeloid and lymphoid lineages are unaffected by this mutation. Retsina mutants that survive to adulthood show complete maturation arrest at the polychromatophilic erythroblast stage with a large percentage of cells have bilobed nuclei. The striking histologic feature of retsina mutant erythroblast are most reminiscent of smears from human patients with dyserythropoietic anemias, particularly HEMPAS (Hereditary Erythroblastic Multinuclearity with Positive Acidified Serum, CDA type 2). The specific aim of this proposal is to clone the retsina gene by a positional cloning strategy in zebrafish. I have mapped the retsina locus with a closely linked marker (0.7 cM based on 10/1380 meiotic recombinants). Candidate genes have been isolated and excluded for retsina using linkage analysis. Genetically linked YAC, BAC and PAC clones have been isolated, and a chromosome walk has been undertaken. After the isolation of the retsina gene in zebrafish, its human homolog will be cloned and examined in human patients with CDA and other dyserythropoietic anemias. The isolation of the human gene will be facilitated by the extensive synteny within this region of the zebrafish and human genome. The cloning of the retsina gene would further our understanding of molecular events in both normal erythrocyte differentiation and dyserythropoietic processes in CDA, myelodysplasia.