Mourkioti Foteini, Slonimsky Esfir, Huth Marion, Berno Valeria, Rosenthal Nadia
Genesis. 2008 Aug;46(8):424-30. doi: 10.1002/dvg.20419.
An increasing number of genes have been implicated in skeletal muscle fiber diversity. To study the contribution of diverse genetic elements to the regulation of fiber-type composition, we generated a transgenic mouse in which CRE recombinase expression is driven by muscle-specific regulatory sequences of the myosin light chain 1/3 locus (MLC). Using ROSA26 conditional reporter mice, we detected expression of the MLC-Cre transgene starting from embryonic day 12.5 (E12.5). By E15, recombination was detected in all muscle-derived structures. Immunohistochemical analysis revealed CRE activity was restricted to fast-twitch (type II) and excluded from slow-twitch (type I) fibers of skeletal muscle. The MLC-Cre transgenic mouse can be used in conjunction with conditional alleles to study both developmental patterning and maintenance of fast fiber-type phenotypes.
越来越多的基因与骨骼肌纤维多样性有关。为了研究多种遗传元件对纤维类型组成调节的贡献，我们构建了一种转基因小鼠，其中CRE重组酶的表达由肌球蛋白轻链1/3基因座（MLC）的肌肉特异性调控序列驱动。使用ROSA26条件报告基因小鼠，我们检测到从胚胎第12.5天（E12.5）开始MLC-Cre转基因的表达。到E15时，在所有肌肉衍生结构中都检测到了重组。免疫组织化学分析显示，CRE活性局限于骨骼肌的快肌（II型）纤维，而慢肌（I型）纤维中没有。MLC-Cre转基因小鼠可与条件等位基因结合使用，以研究快纤维类型表型的发育模式和维持情况。
