Department of Physics and Astronomy, Laser LaB Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Department of Orthopaedic Surgery, Amsterdam University Medical Centers, Amsterdam Movement Sciences, Amsterdam, The Netherlands.
FASEB J. 2020 Sep;34(9):12269-12277. doi: 10.1096/fj.202000896R. Epub 2020 Jul 22.
Embryos are growing organisms with highly heterogeneous properties in space and time. Understanding the mechanical properties is a crucial prerequisite for the investigation of morphogenesis. During the last 10 years, new techniques have been developed to evaluate the mechanical properties of biological tissues in vivo. To address this need, we employed a new instrument that, via the combination of micro-indentation with Optical Coherence Tomography (OCT), allows us to determine both, the spatial distribution of mechanical properties of chick embryos, and the structural changes in real-time. We report here the stiffness measurements on the live chicken embryo, from the mesenchymal tailbud to the epithelialized somites. The storage modulus of the mesoderm increases from (176 ± 18) Pa in the tail to (716 ± 117) Pa in the somitic region (mean ± SEM, n = 12). The midline has a mean storage modulus of (947 ± 111) Pa in the caudal (PSM) presomitic mesoderm (mean ± SEM, n = 12), indicating a stiff rod along the body axis, which thereby mechanically supports the surrounding tissue. The difference in stiffness between midline and presomitic mesoderm decreases as the mesoderm forms somites. This study provides an efficient method for the biomechanical characterization of soft biological tissues in vivo and shows that the mechanical properties strongly relate to different morphological features of the investigated regions.
胚胎是具有高度时空异质性的生物体。了解其力学性质是研究形态发生的关键前提。在过去的 10 年中，已经开发出了新的技术，可以在体内评估生物组织的力学性质。为了满足这一需求，我们采用了一种新的仪器，该仪器通过将微压痕与光相干断层扫描（OCT）相结合，可以实时确定鸡胚的力学性质的空间分布和结构变化。我们在这里报告了对活体鸡胚的刚度测量，从间质尾部芽到上皮化体节。中胚层的储能模量从尾部的（176±18）Pa 增加到体节区域的（716±117）Pa（平均值±SEM，n=12）。中线在尾部（PSM）前体节中胚层的储能模量平均值为（947±111）Pa（平均值±SEM，n=12），表明沿身体轴存在一个刚性棒，从而机械地支撑周围组织。中胚层和前体节中胚层之间的刚度差异随着中胚层形成体节而减小。这项研究为活体软生物组织的生物力学特性提供了一种有效的方法，并表明力学性质与所研究区域的不同形态特征密切相关。
