Testing the tissue-specific mechanisms of Hoxa5 function in musculoskeletal patterning

测试 Hoxa5 在肌肉骨骼模式中功能的组织特异性机制

• 批准号: 9351838
• 负责人: Jennifer H Mansfield
• 金额: $ 38.95万
• 依托单位: BARNARD COLLEGE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-09 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9351838
• 关键词: Address; Alleles; Animals; Anterior; Arts; Behavior; Binding Sites; Body Patterning; Bone Development; Cartilage; Cell physiology; Cells; Cervical; Chest; Chondrocytes; Chromatin Structure; Congenital Abnormality; Connective Tissue; Connective Tissue Diseases; Dermis; Development; Disease; Dissection; Dissociation; Elements; Embryo; Endothelium; Epitopes; Flow Cytometry; Gene Targeting; Genes; Genetic; Genetic Transcription; Genomics; Genotype; Goals; HOX protein; Health; High-Throughput Nucleotide Sequencing; Homeobox Genes; Human; Label; Lead; Ligaments; Light; Maintenance; Malignant Neoplasms; Mammals; Maps; Mediating; Molecular; Molecular Genetics; Morphogenesis; Morphology; Mus; Muscle; Muscle Development; Musculoskeletal; Musculoskeletal Development; Mutation; Osteogenesis; Other Genetics; Pathway interactions; Pattern; Phenotype; Play; Positioning Attribute; Process; Proteins; Regulation; Research; Resources; Role; Sclerotome; Signal Transduction; Skeleton; Somites; Specific qualifier value; Specificity; Students; Tendon structure; Testing; Tissues; Training; Underrepresented Groups; Variant; Vertebral column; Vertebrates; Woman; Work; base; bone; cartilage development; chromatin immunoprecipitation; cofactor; college; design; differential expression; experimental study; genetic approach; in vivo; laboratory curriculum; ligament development; loss of function; polyclonal antibody; progressive myositis ossificans; rib bone structure; skeletal; skeletal tissue; student participation; tendon development; transcription factor; transcriptome sequencing; undergraduate student

Abstract Development of cartilage, bones, muscles, tendons and ligaments must be highly coordinated, with tissue type differentiation and morphogenesis occuring in a concerted way that allows the resulting tissues to function together. The axial musculoskeleton (vertebral column and ribs) develops from the somites, in which all musculoskeletal tissue types are specified and develop coordinately. However, the morphology of somite derivatives varies with position along the body axis. This variation is controlled by Hox proteins, conserved transcription factors that pattern the body axis of most animal embryos. In vertebrates, Hox proteins both confer anterior-posterior identity on nascent segments and play direct roles in tissue morphogenesis later in development. However, we still know relatively little about their mechanisms of action, including the cell and tissue types in which they act, the cellular behaviors they regulate, and ultimately their transcriptional targets. Hoxa5 non-redundantly patterns musculoskeletal elements at the cervical-thoracic transition. In order to understand how it acts, we used genetic lineage labeling to fate map the descendants of Hoxa5 expressing cells. We found that Hoxa5 descendants contribute to a restricted number tissue types, such as cartilage and perichondrium, but only contribute rarely to tendon and never to muscle. This restriction of Hoxa5 descendant fate may reflect an important aspect of its function. Here, we propose to investigate the mechanism through which Hoxa5 patterns the cervical-thoracic transition musculoskeleton of mice, using a combination of genetic lineage labeling, conditional and loss-of-function analysis, and high throughput sequencing. Our specific aims are designed to: (1) Identify the tissue specificity of Hoxa5 action in patterning the axial skeleton (2) Identify genes and gene networks regulated cell-autonomously by Hoxa5 and (3) Identify direct transcriptional targets of Hoxa5 in the somites. Successful completion of this project will shed light on the mechanisms through which axial patterning is regulated by Hox genes, and can also be applied to a general understanding the mechanisms of Hoxa5 in other tissue types and cancers. More generally, the work is relevant to human health through its application to understanding musculoskeletal tissue patterning and differentiation during normal development and disease. Finally, this work will be conducted with undergraduates at Barnard College, a liberal arts college for women. It will be performed by research students in the PI’s lab, and will be introduced into a newly developed, full year laboratory course at Barnard. Course-based research has been shown to increase participation of students, including those from underrepresented groups, in STEM and to increase the pursuit of postgraduate STEM training. This course will engage undergraduates in substantive original research while providing them with training in current molecular genetics approaches.

摘要 软骨、骨骼、肌肉、肌腱和韧带的发育必须高度协调， 组织类型分化和形态发生以一种协调的方式发生， 组织一起工作。中轴肌肉骨骼（脊柱和肋骨）从脊柱发育而来。 体节，其中所有肌肉骨骼组织类型被指定并协调发展。但 体节衍生物的形态随体轴沿着的位置而变化。这种变化是由 Hox蛋白是一种保守的转录因子，在大多数动物胚胎的体轴中起作用。在 在脊椎动物中，Hox蛋白既赋予新生节的前后一致性，又直接起作用。 在发育后期组织形态发生中的作用。然而，我们对它们的了解仍然相对较少。 作用机制，包括它们作用的细胞和组织类型，它们的细胞行为， 调节，并最终调节它们的转录靶点。Hoxa 5非冗余模式肌肉骨骼 颈胸过渡区的元素。为了了解它的作用，我们使用了遗传谱系 标记以绘制表达Hoxa 5的细胞的后代的命运图。我们发现Hoxa 5的后代 有助于有限数量的组织类型，如软骨和软骨膜，但仅有助于 很少发生在肌腱，从不发生在肌肉。这种对Hoxa 5后代命运的限制可能反映了一个重要的 它的功能方面。在这里，我们建议研究Hoxa 5模式的机制， 小鼠颈胸过渡肌肉骨骼，使用遗传谱系标记的组合， 条件分析和功能丧失分析，以及高通量测序。我们的具体目标是 设计用于：（1）确定Hoxa 5在中轴骨骼模式化中作用的组织特异性（2） 鉴定Hoxa 5细胞自主调控的基因和基因网络;（3）直接鉴定 Hoxa 5在体节中的转录靶标。该项目的成功完成将揭示 Hox基因调控轴向模式的机制，也可以应用于 Hoxa 5在其他组织类型和癌症中的作用机制。更一般地 工作是相关的人类健康，通过其应用，以了解肌肉骨骼组织 在正常发育和疾病过程中的模式化和分化。最后，这项工作将 在巴纳德学院（一所女子文理学院）的本科生中进行。它将被执行 由PI实验室的研究生进行，并将被引入一个新开发的全年实验室 在Barnard。以课程为基础的研究已被证明可以增加学生的参与， 包括那些来自代表性不足的群体，在STEM和增加追求研究生 STEM培训本课程将使本科生从事实质性的原创性研究，同时提供 他们在当前的分子遗传学方法的培训。