• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Mice Lacking Skeletal Muscle Actin Show Reduced Muscle Strength and Growth Deficits and Die during the Neonatal Period
【24h】

Mice Lacking Skeletal Muscle Actin Show Reduced Muscle Strength and Growth Deficits and Die during the Neonatal Period

机译：缺乏骨骼肌肌动蛋白的小鼠在新生儿期显示出降低的肌肉强度和生长缺陷和死亡

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

All four of the muscle actins (skeletal, cardiac, vascular, and enteric) in higher vertebrates show distinct expression patterns and display highly conserved amino acid sequences. While it is hypothesized that each of the muscle isoactins is specifically adapted to its respective tissue and that the minor variations among them have developmental and/or physiological relevance, the exact functional and developmental significance of these proteins remains largely unknown. In order to begin to assess these issues, we disrupted the skeletal actin gene by homologous recombination. All mice lacking skeletal actin die in the early neonatal period (day 1 to 9). These null animals appear normal at birth and can breathe, walk, and suckle, but within 4 days, they show a markedly lower body weight than normal littermates and many develop scoliosis. Null mice show a loss of glycogen and reduced brown fat that is consistent with malnutrition leading to death. Newborn skeletal muscles from null mice are similar to those of wild-type mice in size, fiber type, and ultrastructural organization. At birth, both hemizygous and homozygous null animals show an increase in cardiac and vascular actin mRNA in skeletal muscle, with no skeletal actin mRNA present in null mice. Adult hemizygous animals show an increased level of skeletal actin mRNA in hind limb muscle but no overt phenotype. Extensor digitorum longus (EDL) muscle isolated from skeletal-actin-deficient mice at day 2 to 3 showed a marked reduction in force production compared to that of control littermates, and EDL muscle from hemizygous animals displayed an intermediate force generation. Thus, while increases in cardiac and vascular smooth-muscle actin can partially compensate for the lack of skeletal actin in null mice, this is not sufficient to support adequate skeletal muscle growth and/or function.
机译：高等脊椎动物中的所有四种肌动蛋白（骨骼，心脏，血管和肠溶）均显示出不同的表达模式，并显示出高度保守的氨基酸序列。尽管假设每种肌肉异肌动蛋白都特别适应于其各自的组织，并且它们之间的微小差异具有发育和/或生理相关性，但这些蛋白质的确切功能和发育意义仍然非常未知。为了开始评估这些问题，我们通过同源重组破坏了骨骼肌肌动蛋白基因。所有缺少骨骼肌动蛋白的小鼠都在新生儿早期（第1至9天）死亡。这些无动物的动物在出生时看起来很正常，可以呼吸，行走和吮吸，但是在4天之内，它们的体重却明显低于正常同窝仔，并且许多人都患有脊柱侧弯。空小鼠显示糖原损失和褐色脂肪减少，这与营养不良导致死亡相一致。空小鼠的新生骨骼肌在大小，纤维类型和超微结构方面与野生型小鼠相似。出生时，半合子和纯合子无效动物均显示骨骼肌中的心脏和血管肌动蛋白mRNA增加，而无效小鼠中不存在骨骼肌动蛋白mRNA。成年半合子动物后肢肌肉中骨骼肌肌动蛋白mRNA水平升高，但没有明显的表型。从第2天到第3天从骨骼肌动蛋白缺乏症小鼠中分离出的指伸肌（EDL）肌肉与对照组的同窝仔相比，力量产生显着降低，半合子动物的EDL肌肉表现出中等的力量产生。因此，尽管心脏和血管平滑肌肌动蛋白的增加可以部分补偿空小鼠中骨骼肌肌动蛋白的缺乏，但这不足以支持足够的骨骼肌生长和/或功能。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号