Revealing how cytoskeletal dynamics form the early mammalian embryo

揭示细胞骨架动力学如何形成早期哺乳动物胚胎

基本信息

批准号：
10117399
负责人：
Nicolas Daniel Plachta
金额：
$ 51.4万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-01 至 2026-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10117399
关键词：
Actins Address Apical Automobile Driving Cell Communication Cell Differentiation process Cell Lineage Cell Nucleus Cell Polarity Cell Separation Cell division Cells Cytokeratin filaments Data Development Elements Embryo Event F-Actin Fetus Filament Future Goals Image Implant Inherited Inner Cell Mass Intermediate Filaments Interphase Keratin Length Mammalian Cell Measurement Mechanics Microtubules Mitosis Modeling Molecular Molecular Chaperones Movement Mus Nonmammalian Embryo Nuclear Organism PARD6A gene Pattern Placenta Pregnancy Process Proteins Role Specific qualifier value Testing Time To specify Uterus Work base biophysical properties biophysical techniques blastocyst cell cortex cell type daughter cell embryo cell embryo stage 2 genetic risk factor imaging approach in vivo mechanical force molecular asymmetry molecular dynamics mouse development overexpression preimplantation premature scaffold segregation transcription factor

项目摘要

SUMMARY Revealing the key events that specify the first differentiated cell lineages during mammalian development is key to understand how the early embryo is organized to implant in the uterus and establish a pregnancy. The first mammalian cell lineages comprise the pluripotent inner cell mass (ICM) that will form the fetus, and the outer trophectoderm that will form the placenta. Yet, the mechanisms explaining how these lineages differentiate are unclear. In many non-mammalian embryos, asymmetrically inherited cell-fate determinants specify lineage fate, yet similar mechanisms are thought to be absent during early mammalian development. We have established live-imaging approaches to study cell and molecular dynamics during early mouse development. Recently, we identified a new role for intermediate filaments assembled by keratins in lineage specification. Our studies reveal that keratin filaments are asymmetrically inherited precisely during the cell divisions that physically segregate the future ICM and trophectoderm. Moreover, the inheritance of these filaments by the outer daughter cells helps to specify their trophectoderm identity and promote their maturation. Thus, our main hypothesis is that keratin filaments function as a new form of asymmetrically inherited factor specifying the first trophectoderm cells during development. To test this, we will reveal the mechanisms by which keratins become asymmetrically inherited (Aim 1) and can bias cell fate (Aim 2). We will first test how interactions with proteins present at the apical cell cortex, and the dynamics of the filaments inside the cell, control their asymmetric inheritance by outer cells during cell division. We will then determine how keratins can regulate key aspects of cell mechanics and polarity to control the distribution of the key transcription factors that specify trophectoderm fate. In summary, in this proposal we will address a fundamental open question about the specification of the first differentiated cell lineages during mammalian development, and unveil some of the first functions of keratin intermediated filaments during early mammalian development, which unlike those of other cytoskeletal elements like microtubules and actin, remain largely unknown.

概括揭示指定在哺乳动物发育过程中指定第一个分化细胞谱系的关键事件是关键了解如何组织早期胚胎在子宫中植入并建立怀孕。第一个哺乳动物细胞谱系包括将形成胎儿的多能内部细胞质量（ICM），外部将形成胎盘的滋养剂。然而，解释了这些谱系分化的机制不清楚。在许多非哺乳动物胚胎中，非对称遗传的细胞命令决定因素指定谱系命运，然而，在哺乳动物早期发育期间，人们认为类似的机制被认为存在。我们已经建立了在早期小鼠期间研究细胞和分子动力学的实影现象方法发展。最近，我们确定了角蛋白在谱系中组装的中间细丝的新作用规格。我们的研究表明，角蛋白丝是在细胞中精确地遗传的物理隔离未来的ICM和滋养剂的分裂。而且，这些的继承外部子细胞的细丝有助于指定其滋养外的身份并促进其成熟。因此，我们的主要假设是角蛋白丝是一种不对称因素的新形式在发育过程中指定第一个滋养外胚层细胞。为了测试这一点，我们将揭示该机制角蛋白成为不对称的遗传（AIM 1），并且会偏向细胞的命运（AIM 2）。我们将首先测试与蛋白质在顶端细胞皮质处存在的相互作用以及细丝的动力学在细胞内部，控制细胞分裂期间外细胞的不对称遗传。然后，我们将确定如何角蛋白可以调节细胞力学和极性的关键方面，以控制关键转录的分布指定滋养剂命运的因素。总而言之，在此提案中，我们将解决有关第一个规范的基本公开问题哺乳动物发育过程中分化的细胞谱系，并揭示角蛋白的一些第一功能哺乳动物早期发育过程中的介导的细丝，这与其他细胞骨架元素不同像微管和肌动蛋白一样，在很大程度上仍然未知。