Gene deletion by the Cre-Loxp system has facilitated functional studies of many critical genes in mice, offering important insights and allowing deeper understanding on the mechanisms underlying organ development and diseases, such as heart development and diseases. In this study, we generated a Myh6-Cre knockin mouse model by inserting the IRES-Cre-wpre-polyA cassette between the translational stop codon and the 3′ untranslated region of the endogenous Myh6 gene. By crossing knockin mice with the Rosa26 reporter lines, we found that Myh6-Cre targeted cardiomyocytes at the embryonic and postnatal stages. In addition, we were able to inactivate the desmosome gene Desmoplakin (Dsp) by breeding Myh6-Cre mice with a conditional Dsp^flox knockout mouse line, which resulted in embryonic lethality during the mid-term pregnancy. These results suggest that the new Myh6-Cre mouse line can serve as a robust tool to dissect the distinct roles of genes involved in heart development and function.

Cre-Loxp 系统的基因缺失促进了对小鼠许多关键基因的功能研究，提供了重要的见解，并有助于更深入地了解器官发育和疾病（如心脏发育和疾病）的机制。在这项研究中，我们通过在翻译终止密码子和内源性Myh6基因的 3' 非翻译区之间插入 IRES-Cre-wpre-polyA 盒来生成Myh6-Cre敲入小鼠模型。通过将敲入小鼠与Rosa26报告系交叉，我们发现Myh6-Cre在胚胎和出生后阶段靶向心肌细胞。此外，我们能够通过培育Myh6-Cre使桥粒基因 Desmoplakin (Dsp) 失活具有条件Dsp ^flox敲除小鼠系的小鼠，这导致中期妊娠期间的胚胎致死率。这些结果表明，新的Myh6-Cre小鼠系可以作为一个强大的工具来剖析参与心脏发育和功能的基因的不同作用。