Studying embryo development by novel microscopy techniques for improving IVF screening

体外受精(IVF)已经使用了大约40年，但它仍然是一种效率低下的程序(成功率只有26%)，而且费用昂贵。最常见的失败原因是胚胎的染色体数量错误(称为非整倍体)，以及没有以正确的速度新陈代谢的胚胎--这些很难在不对胚胎造成伤害的情况下确定。为了改进对合格卵子/胚胎的筛查和诊断，这项技术应该能够提供染色体含量和代谢率的客观信息，但也必须是非侵入性、无标记和非破坏性的。目前的方法大多仅依靠成像形态，这本身就不足以反映发育中的胚胎的健康状况。因此，这个项目的首要目标是解决这个问题，提高试管受精的效率。该项目旨在开发评估卵子/胚胎健康和研究早期胚胎发育的方法，以最终改善试管受精患者的结局。然而，为了进行这种研究，需要非侵入性和非破坏性技术。光学技术可以是非侵入性的，但大多数当前的方法依赖于使用荧光标签或染料进行可视化。此外，传统的共聚焦显微镜成像会产生光毒性。光片显微镜是一种新兴的新型显微技术，可以提供无损伤的快速3D可视化。在我们团队中，我们最近开发了使用低能量近红外光和双光子成像的无标记光片显微镜。在这个项目中，我们将使用这种方法来研究小鼠体外受精模型中的非整倍体和新陈代谢，开发出以最少的光输入提取最多信息的方法。图像分析方法的发展也将有助于卵子、精子和胚胎的快速筛选。然后，这些方法将在伦理批准下应用于人体样本。

In vitro fertilisation (IVF) has been used for ~40 years but it remains an inefficient procedure (only ~26% success rate) and is expensive. Among the most common causes of failure are the embryos having the wrong number of chromosomes (termed 'aneuploidy') and embryos that that are not metabolising at the correct rate - these are difficult to determine without causing harm to the embryo. To improve screening and diagnosis for competent eggs/embryos the technology should be able to provide objective information of chromosome content and metabolic rate, but must also be non-invasive, label-free and non-destructive. Current methods mostly rely on imaging morphology alone, which by itself is an insufficient marker of the health of the developing embryo. Hence the overarching goal of this project is to address this and improve the efficiency of IVF. The project aims to develop methodologies to evaluate egg/embryo health and study early embryo development in order to ultimately improve outcomes for IVF patients. However, in order to perform such studies non-invasive and non-destructive technologies are needed. Optical technologies can be non-invasive but most current methods rely on use of fluorescent labels or dyes for visualisation. Furthermore, conventional imaging with confocal microscopy causes light-toxicity. Light sheet microscopy is an emerging novel microscopy technique that can provide damage-free rapid 3D visualisation. In our group we have recently developed label-free light sheet microscopy using low-energy near infrared light and two-photon imaging. In this project we will use this approach to study aneuploidy and metabolism in a mouse IVF model, developing ways of extracting the most information for the least light input. Development of image analysis approaches will also aid the rapid screening of eggs, sperm and embryos. These approaches will then be applied to human samples under ethical approval.