Cheverud J M, Hartman S E, Richtsmeier J T, Atchley W R
Department of Anatomy & Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110.
J Craniofac Genet Dev Biol. 1991 Jul-Sep;11(3):122-37.
We analyzed patterns of mandibular genetic and phenotypic morphological integration and the relationship of genealogy to interstrain molecular and morphological differences in ten inbred strains of mice. Positions of mandibular landmarks in two-dimensional space were used to construct a finite element mesh for each individual, then all individuals from the ten strains were compared to the average mandible from a standard strain (SEA/GnJ). Measures of size and shape associated with finite element scaling analysis were then used in a quantitative genetic analysis of mandibular variation. Significant genetic variation for mandibular size and shape was uncovered. Patterns of both genetic and phenotypic correlation for measures of landmark-specific sizes were consistent with models of morphological integration based on the developmental origin of parts of the mandible and on the effects of muscle attachment on mandibular morphology. Shape differences local to particular landmarks did not show these forms of morphological integration. Although interstrain distances based on local shape magnitudes were significantly correlated with genealogical relationship, distances based on local size differences were not. Even higher than the correlation of genealogy with distances based on local shape magnitude was the genealogical-molecular distance correlation. Patterns of morphometric mandibular variation corresponded to expected effects of epigenetic developmental processes. Also, when detailed shape differences were considered, morphology served as a rough guide to genealogy, although molecular distances showed a stronger relationship.
我们分析了10个近交系小鼠下颌骨的遗传和表型形态整合模式，以及谱系与品系间分子和形态差异的关系。利用二维空间中下颌骨标志点的位置为每个个体构建有限元网格，然后将10个品系的所有个体与一个标准品系（SEA/GnJ）的平均下颌骨进行比较。与有限元缩放分析相关的大小和形状测量值随后被用于下颌骨变异的数量遗传学分析。研究发现下颌骨大小和形状存在显著的遗传变异。标志点特定大小测量值的遗传和表型相关性模式，与基于下颌骨各部分发育起源以及肌肉附着对下颌骨形态影响的形态整合模型一致。特定标志点局部的形状差异并未表现出这些形态整合形式。尽管基于局部形状量值的品系间距离与谱系关系显著相关，但基于局部大小差异的距离则不然。谱系与分子距离的相关性甚至高于谱系与基于局部形状量值的距离的相关性。下颌骨形态测量变异模式与表观遗传发育过程的预期效应相符。此外，当考虑详细的形状差异时，形态学可作为谱系的粗略指南，尽管分子距离显示出更强的关系。
