研究人员表示，该技术也可用于人类胚胎，可能有助于解决长期以来关于胚胎里的细胞究竟什么时候开始分化成特定细胞类型的争论。

一个新的显微镜让研究人员观察到了迄今为止最详尽的老鼠发育过程细节。这是科学家们第一次得以追踪每一个细胞的分裂过程，从受精卵一直到着床于母鼠的子宫中的被称为胚泡的细胞圆球(见上图)。包括小鼠和人类在内的哺乳动物的胚胎对标准高分辨率显微镜所使用的亮光非常敏感。一种被称之为单层光显微的技术每次只照亮胚胎的一个薄片，减少了活标本的曝光度。现在研究人员已经设计出一个单层光显微镜，可以同时观察多个胚胎，让它们能够以一个稳定的温度保存在生长培养基中。这个技术让科学家们得以均衡个体胚胎间的差异，更好地识别出胚胎发育中有意义的模式。

原文链接：Video: First-of-its-kind movie shows mouse developing from a single cell

原文摘要：A new microscope has given researchers their most detailed view yet of the earliest days of mouse development. For the first time, scientists can track each cell as it divides, from the fertilized egg all the way to the round ball of cells called a blastocyst, which implants in the mother’s uterus (see video, above). Mammalian embryos, including mice and humans, are very sensitive to the bright light used in standard high-resolution microscopes. A technique called light-sheet microscopy illuminates just a thin slice of the embryo at a time, minimizing the living specimen’s exposure. Researchers have now designed a light-sheet microscope that can image multiple embryos at once, keeping them at a stable temperature in their growth media. That allows the scientists to average out the differences between individual embryos and better recognize meaningful patterns in development. They report this week in Nature Methods that in mouse embryos, the first differentiation of cell types happens when the embryo grows from eight to 16 cells. When the cells in the eight-celled embryo divide, cells that end up on the inside (tagged red in this video) continue to develop into the body of the mouse, while those on the outside (tagged blue) go on to form the placenta. The technique could also be used on human embryos, the researchers say, and might help settle a long-running dispute on exactly when cells in the embryo start to differentiate into specific cell types.