Skirball Institute of Biomolecular Medicine and Department of Radiology, New York University Grossman School of Medicine, New York, New York, USA.
Department of Electrical and Computer Engineering, New York University Tandon School of Engineering, New York, New York, USA.
Ultrasound Med Biol. 2023 Jan;49(1):356-367. doi: 10.1016/j.ultrasmedbio.2022.09.008. Epub 2022 Oct 22.
Large-scale international efforts to generate and analyze loss-of-function mutations in each of the approximately 20,000 protein-encoding gene mutations are ongoing using the "knockout" mouse as a model organism. Because one-third of gene knockouts are expected to result in embryonic lethality, it is important to develop non-invasive in utero imaging methods to detect and monitor mutant phenotypes in mouse embryos. We describe the utility of 3-D high-frequency (40-MHz) ultrasound (HFU) for longitudinal in utero imaging of mouse embryos between embryonic days (E) 11.5 and E14.5, which represent critical stages of brain and organ development. Engrailed-1 knockout (En1-ko) mouse embryos and their normal control littermates were imaged with HFU in 3-D, enabling visualization of morphological phenotypes in the developing brains, limbs and heads of the En1-ko embryos. Recently developed deep learning approaches were used to automatically segment the embryonic brain ventricles and bodies from the 3-D HFU images, allowing quantitative volumetric analyses of the En1-ko brain phenotypes. Taken together, these results show great promise for the application of longitudinal 3-D HFU to analyze knockout mouse embryos in utero.
大型国际合作正在使用“ knockout”小鼠作为模型生物，对大约 20,000 个编码蛋白的基因突变中的每一个进行功能丧失突变的产生和分析。由于预计三分之一的基因敲除会导致胚胎致死，因此开发非侵入性的宫内成像方法来检测和监测小鼠胚胎中的突变表型非常重要。我们描述了 3-D 高频（40-MHz）超声（HFU）在胚胎期（E）11.5 至 E14.5 之间对小鼠胚胎进行纵向宫内成像的应用，这代表了大脑和器官发育的关键阶段。使用 HFU 在 3-D 中对 Engrailed-1 敲除（En1-ko）小鼠胚胎及其正常对照同窝仔进行成像，能够可视化 En1-ko 胚胎发育中的大脑、四肢和头部的形态表型。最近开发的深度学习方法用于自动从 3-D HFU 图像中分割胚胎大脑脑室和主体，从而可以对 En1-ko 大脑表型进行定量体积分析。总之，这些结果表明，纵向 3-D HFU 非常有希望用于分析宫内的 knockout 小鼠胚胎。
