Integrative Morphology Group, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria.
Cells Tissues Organs. 2012;196(1):90-8. doi: 10.1159/000330789. Epub 2012 Jan 25.
A 5th pair of pharyngeal arch arteries (PAAs) has never been identified with certainty in mice. Murines in general are considered to not develop a 5th pair. If true, the significance of the mouse as a model for researching the genesis of malformations of the great intrathoracic arteries is limited. We aimed to investigate whether mouse embryos develop a 5th pair of PAAs and to identify malformations known to be caused by defective remodelling of the 5th PAAs. We employed the high-resolution episcopic microscopy method for creating digital volume data and three-dimensional (3D) computer models of the great intrathoracic arteries of 30 mouse embryos from days 12-12.5 post conception and 180 mouse fetuses from days 14.5 and 15.5 post conception. The 3D models of the fetuses were screened for the presence of a double-lumen aortic arch malformation. We identified such a malformation in 1 fetus. The 3D models of the embryos were analysed for the presence of 5th PAAs. Six of the 30 embryos (20%) showed a 5th PAA bilaterally, and an additional 9 (30%) showed a 5th PAA unilaterally. Our results prove that some mice do develop a 5th pair of PAAs. They also show that malformations which occur rarely in humans and result from defective remodelling of the left 5th PAA can be identified in mice as well. Thus, the mouse does represent an excellent model for researching the mechanisms driving PAA remodelling and the genesis of malformations of the great intrathoracic arteries.
第五对咽弓动脉（PAAs）在小鼠中从未被确定过。一般来说，老鼠被认为不会发育出第五对。如果这是真的，那么老鼠作为研究大胸内动脉畸形发生机制的模型的意义就有限了。我们旨在研究小鼠胚胎是否发育出第五对 PAAs，并确定已知由第五对 PAAs 重塑缺陷引起的畸形。我们采用高分辨率的外照显微镜方法，对 30 只妊娠 12-12.5 天的小鼠胚胎和 180 只妊娠 14.5 天和 15.5 天的胎儿的大胸内动脉进行了数字体积数据和三维（3D）计算机建模。对胎儿的 3D 模型进行了筛查，以确定是否存在双腔主动脉弓畸形。我们在 1 只胎儿中发现了这样的畸形。对胚胎的 3D 模型进行了分析，以确定是否存在第五对 PAAs。30 只胚胎中有 6 只（20%）双侧出现第五对 PAAs，另外 9 只（30%）单侧出现第五对 PAAs。我们的结果证明，一些老鼠确实发育出了第五对 PAAs。它们还表明，在人类中很少发生且由左侧第五对 PAAs 重塑缺陷引起的畸形也可以在老鼠中被识别。因此，老鼠确实是研究 PAAs 重塑机制和大胸内动脉畸形发生机制的优秀模型。
