Department of Biological and Environmental Sciences, Texas A&M University-Commerce, Commerce, TX 75429-3011, USA.
J Biomed Sci. 2013 Mar 23;20(1):20. doi: 10.1186/1423-0127-20-20.
A recessive mutation "c" in the Mexican axolotl, Ambystoma mexicanum, results in the failure of normal heart development. In homozygous recessive embryos, the hearts do not have organized myofibrils and fail to beat. In our previous studies, we identified a noncoding Myofibril-Inducing RNA (MIR) from axolotls which promotes myofibril formation and rescues heart development.
We randomly cloned RNAs from fetal human heart. RNA from clone #291 promoted myofibril formation and induced heart development of mutant axolotls in organ culture. This RNA induced expression of cardiac markers in mutant hearts: tropomyosin, troponin and α-syntrophin. This cloned RNA matches in partial sequence alignment to human microRNA-499a and b, although it differs in length. We have concluded that this cloned RNA is unique in its length, but is still related to the microRNA-499 family. We have named this unique RNA, microRNA-499c. Thus, we will refer to this RNA derived from clone #291 as microRNA-499c throughout the rest of the paper.
This new form, microRNA-499c, plays an important role in cardiac development.
墨西哥钝口螈（Ambystoma mexicanum）中的隐性突变“c”导致心脏发育异常。在纯合隐性胚胎中，心肌没有有组织的肌原纤维，也无法跳动。在我们之前的研究中，我们从墨西哥钝口螈中鉴定出一种非编码肌原纤维诱导 RNA（MIR），它可以促进肌原纤维的形成并挽救心脏发育。
我们从胎牛心脏中随机克隆 RNA。来自克隆#291 的 RNA 促进肌原纤维形成，并在器官培养中诱导突变型墨西哥钝口螈的心脏发育。这种 RNA 在突变型心脏中诱导了心脏标志物的表达：原肌球蛋白、肌钙蛋白和α-肌联蛋白。该克隆 RNA 在部分序列比对上与人类 microRNA-499a 和 b 匹配，尽管长度不同。我们得出结论，该克隆 RNA 长度独特，但仍与 microRNA-499 家族有关。我们将这种独特的 RNA 命名为 microRNA-499c。因此，在本文的其余部分，我们将从克隆#291 中获得的这种 RNA 称为 microRNA-499c。
这种新形式的 microRNA-499c 在心脏发育中起着重要作用。
