Laboratory of Stem Cell and Neuro-Vascular Biology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA; Division of Pediatric Cardiology, Children's National Hospital, Washington, DC, USA.
Laboratory of Stem Cell and Neuro-Vascular Biology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
Ultrasound Med Biol. 2021 Mar;47(3):751-758. doi: 10.1016/j.ultrasmedbio.2020.11.008. Epub 2020 Dec 5.
In vivo micro-imaging of mice is useful in studying the genetic basis of cardiac development in mutant embryos. We examined Phox2b mutant mice, which lack autonomic innervation to the heart and die in utero, and investigated whether this lack of innervation causes cardiac dysfunction during embryogenesis. A VisualSonics Vevo 2100 ultrahigh-frequency linear array ultrasound machine with 30- and 40-MHz probes was used to analyze embryo size, gross characteristics, ventricular contractility and rhythm. Phox2b mutant embryos underwent cessation of heartbeat and death at a greater rate than wild-type controls. We did not observe a hydrops phenotype or congenital heart defects in Phox2b mutants. Analysis of heart rhythm revealed no significant correlation with genotype. Absent these signs of a progressive pathology, we suggest that Phox2b mutant embryos likely die of sudden death secondary to acute arrhythmia. These data provide insight into the role of cardiac autonomic innervation during development.
体内小鼠微成像可用于研究突变胚胎心脏发育的遗传基础。我们研究了 Phox2b 突变小鼠，这些小鼠缺乏对心脏的自主神经支配，在子宫内死亡，并研究了这种缺乏神经支配是否会导致胚胎发生期间的心脏功能障碍。使用 VisualSonics Vevo 2100 超高频率线性阵列超声机和 30-40MHz 探头分析胚胎大小、大体特征、心室收缩性和节律。Phox2b 突变胚胎的心跳停止和死亡速度比野生型对照更快。我们在 Phox2b 突变体中未观察到水肿表型或先天性心脏缺陷。对心律的分析显示与基因型无显著相关性。如果没有这些进行性病理的迹象，我们认为 Phox2b 突变胚胎可能死于急性心律失常引起的猝死。这些数据提供了对心脏自主神经支配在发育过程中的作用的深入了解。
