第二心场(SHF)在心脏发育中起着举足轻重的作用,特别是在流出道(OFT)形态发生和分隔中,以及右心室(RV)的扩张。两条鼠标Cre线,Mef2c-AHF-Cre(Mef2c-Cre)和Isl1-Cre,已被广泛用于研究SHF的发展。然而,Cre活动不仅在SHF中触发,而且在Mef2c-Cre小鼠的RV中触发,在Isl1-Cre小鼠中,Cre激活不是SHF特异性的。因此,为了更好地理解SHF的发展,更合适的SHF-Cre线是可取的。这里,我们产生并表征了Prdm1-Cre敲入小鼠。与Mef2c-Cre小鼠相比,咽部和内脏中胚层的Cre活性相似,以及Prdm1-Cre小鼠的OFT。尽管如此,注意到与Mef2c-Cre小鼠相比,Prdm1-Cre小鼠的RV中的Cre表达大幅降低。此外,我们使用Mef2c-Cre和Prdm1-Cre小鼠删除了Hand2,Nkx2-5,Pdk1和Tbx20,以研究OFT形态发生和分隔,对这两条Cre线进行比较。在理解SHF发育方面获得了新的见解,包括使用Prdm1-Cre小鼠在OFT中分化成心肌细胞。总之,我们发现Prdm1-Cre鼠标线是一个更合适的工具来监控SHF的发展,而Mef2c-Cre小鼠在研究SHF在OFT形态发生和分隔中的作用和功能方面非常出色。
The second heart field (SHF) plays a pivotal role in heart development, particularly in outflow tract (OFT) morphogenesis and septation, as well as in the expansion of the right ventricle (RV). Two mouse Cre lines, the Mef2c-AHF-Cre (Mef2c-Cre) and Isl1-Cre, have been widely used to study the SHF development. However, Cre activity is triggered not only in the SHF but also in the RV in the Mef2c-Cre mice, and in the Isl1-Cre mice, Cre activation is not SHF-specific. Therefore, a more suitable SHF-Cre line is desirable for better understanding SHF development. Here, we generated and characterized the Prdm1-Cre knock-in mice. In comparison with Mef2c-Cre mice, the Cre activity is similar in the pharyngeal and splanchnic mesoderm, and in the OFT of the Prdm1-Cre mice. Nonetheless, it was noticed that Cre expression is largely reduced in the RV of Prdm1-Cre mice compared to the Mef2c-Cre mice. Furthermore, we deleted Hand2, Nkx2-5, Pdk1 and Tbx20 using both Mef2c-Cre and Prdm1-Cre mice to study OFT morphogenesis and septation, making a comparison between these two Cre lines. New insights were obtained in understanding SHF development including differentiation into cardiomyocytes in the OFT using Prdm1-Cre mice. In conclusion, we found that Prdm1-Cre mouse line is a more appropriate tool to monitor SHF development, while the Mef2c-Cre mice are excellent in studying the role and function of the SHF in OFT morphogenesis and septation.