Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA.
NMR Biomed. 2013 Feb;26(2):224-31. doi: 10.1002/nbm.2843. Epub 2012 Aug 22.
Both the availability of methods to manipulate genes and the completion of the mouse genome sequence have led to the generation of thousands of genetically modified mouse lines that provide a new platform for the study of mammalian development and developmental diseases. Phenotyping of mouse embryos has traditionally been performed on fixed embryos by the use of ex vivo histological, optical and high-resolution MRI techniques. Although potentially powerful, longitudinal imaging of individual animals is difficult or impossible with conventional optical methods because of the inaccessibility of mouse embryos inside the maternal uterus. To address this problem, we present a method of imaging the mouse embryo from stages as early as embryonic day (E)10.5, close to the onset of organogenesis in most physiological systems. This method uses a self-gated MRI protocol, combined with image registration, to obtain whole-embryo high-resolution (100 µm isotropic) three-dimensional images. Using this approach, we demonstrate high contrast in the cerebral vasculature, limbs, spine and central nervous system without the use of contrast agents. These results indicate the potential of MRI for the longitudinal imaging of developing mouse embryos in utero and for future applications in analyzing mutant mouse phenotypes.
基因操作方法的可用性和小鼠基因组序列的完成，导致了数千种基因修饰小鼠品系的产生，为哺乳动物发育和发育性疾病的研究提供了新的平台。传统上，通过使用离体组织学、光学和高分辨率 MRI 技术，对固定的胚胎进行小鼠胚胎表型分析。尽管具有潜在的强大功能，但由于难以或不可能对母体子宫内的小鼠胚胎进行常规光学方法的纵向成像，因此对单个动物进行纵向成像变得很困难。为了解决这个问题，我们提出了一种从胚胎期（E）10.5 阶段开始对小鼠胚胎进行成像的方法，该阶段接近大多数生理系统器官发生的开始。该方法使用自门控 MRI 协议，结合图像配准，获得整个胚胎高分辨率（100 µm 各向同性）三维图像。使用这种方法，我们在不使用造影剂的情况下，在大脑血管、四肢、脊柱和中枢神经系统中获得了高对比度。这些结果表明 MRI 具有对子宫内发育中的小鼠胚胎进行纵向成像的潜力，并具有分析突变小鼠表型的未来应用。
