GENETIC ANALYSIS--DYSERYTHROPOIETIC ANEMIA IN ZEBRAFISH

说明(改编自应用程序) 造血是由多能干细胞引发的一系列事件。 到终末分化的血细胞。该信号中的缺陷 级联可导致红细胞生成障碍并揭示重要的分子 红细胞分化中的事件和潜在过程。 在各种先天性和获得性红细胞生成障碍中观察到。 表明骨髓应激的贫血，如先天性 红细胞生成性贫血(CDA)、骨髓增生异常综合征、白血病 巨幼细胞性贫血、艾滋病毒感染、骨髓康复 移植和溶血性贫血。充分理解这一精髓 应激反应等待对参与这一级联反应的基因的识别 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。合并后的 斑马鱼的遗传和胚胎学优势使其成为理想的模式 用于研究造血发育事件的系统。近45 斑马鱼突变，代表大约25个基因，在 造血功能已被确认。其中一种斑马鱼的血液突变 视网膜炎是一种常染色体隐性遗传病，导致一种 受精后3d出现重度贫血。使用分子标记和 组织学特征，我们显示髓系和淋巴系是 不受这种突变的影响。活到成年的视网膜突变体 在多染红细胞中显示完全成熟停滞 具有较大比例细胞的阶段有双叶核。那次罢工 视网膜突变型红细胞的组织学特征最令人想起 人类红细胞生成性贫血患者的涂片，特别是 阳性酸化遗传性红细胞多核细胞性 血清，CDA 2型)。这项提议的具体目的是克隆 斑马鱼视黄酸基因的定位克隆策略。我已经绘制了地图 带有紧密连锁标记的视网膜基因座(根据10/1380计算为0.7厘米 减数分裂重组体)。候选基因已被分离并排除在 Retsina使用连锁分析。遗传连锁的YAC、BAC和PAC克隆 已经分离出来，并进行了染色体行走。后 分离斑马鱼的retsina基因，其人类同源物将是 CDA和其他红细胞生成障碍患者的克隆和检测 贫血。人类基因的分离将通过 斑马鱼和人类基因组这一区域内广泛的同步性。 视网膜基因的克隆将进一步加深我们对 正常红细胞分化和正常红细胞分化中的分子事件 CDA中的红细胞生成异常，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.