Atchley W R, Herring S W, Riska B, Plummer A A
J Craniofac Genet Dev Biol. 1984;4(3):179-89.
Muscular dysgenesis (mdg) is an autosomal recessive gene in mice affecting primarily the skeletal musculature. mdg/mdg mice exhibit developmental arrest of myogenesis and degenerative changes in all skeletal muscles. In addition, there are pronounced abnormalities in skeletal traits, including the shape of the skull and mandible. Herein, we examine the phenotypic consequences of a single mdg allele in the heterozygous condition (+/mdg) on the size, shape, and developmental stability in 14 osteometric traits from the mouse mandible. Developmental stability in the mandible is measured by fluctuating asymmetry in bilateral traits. There are no statistically significant differences in the size or shape of the mandible between +/+ and +/mdg mice. However, compared to +/+ mice, +/mdg individuals exhibit less developmental stability for several mandible traits. The more unstable traits include height at the mandibular notch, height at the incisive process, condyloid width, height and area of the coronoid process, and size of the tooth-bearing region. All of these latter traits are closely associated with areas of muscle attachment and/or the muscular dysgenesis phenotype, suggesting that the presence of a single mdg allele is sufficient to alter developmental pathways. Traits not showing significantly increased instability in +/mdg mice bear no clear relationship to either muscle attachment areas or to the mdg/mdg phenotype.
肌肉发育不全（mdg）是小鼠中的一种常染色体隐性基因，主要影响骨骼肌肉组织。mdg/mdg小鼠表现出肌生成的发育停滞以及所有骨骼肌的退行性变化。此外，骨骼特征存在明显异常，包括头骨和下颌骨的形状。在此，我们研究了杂合状态（+/mdg）下单个mdg等位基因对小鼠下颌骨14个骨测量性状的大小、形状和发育稳定性的表型影响。下颌骨的发育稳定性通过双侧性状的波动不对称性来衡量。+/+和+/mdg小鼠在下颌骨的大小或形状上没有统计学上的显著差异。然而，与+/+小鼠相比，+/mdg个体在几个下颌骨性状上表现出较低的发育稳定性。更不稳定的性状包括下颌切迹高度、切牙突高度、髁突宽度、冠突高度和面积以及含牙区大小。所有这些后述性状都与肌肉附着区域和/或肌肉发育不全表型密切相关，这表明单个mdg等位基因的存在足以改变发育途径。在+/mdg小鼠中未显示出明显增加的不稳定性的性状与肌肉附着区域或mdg/mdg表型均无明确关系。
