Epigenetic mechanical factors in the evolution of long bone epiphyses
Epigenetic mechanical factors in the evolution of long bone epiphyses
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DOI：
10.1006/zjls.1997.0108
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发表时间：
1998-06-01
影响因子：
2.8
通讯作者：
Padian, K
中科院分区：
文献类型：
--
作者：
Carter, DR;Mikic, B;Padian, K
在发育中的脊椎动物长骨中，软骨内骨化发生在软骨膜骨化之前或伴随有软骨膜骨化。软骨膜附着相对于软骨内骨化的速度和程度在不同的分类群中不同。软骨周围骨化在已灭绝的四足动物和恐龙、现存的硬骨鱼、两栖动物和鸟类的早期长骨发育中占主导地位。在哺乳动物和蜥蜴中，软骨膜骨化和软骨内骨化同步进行。骨骼发育中最重要的表观遗传因素之一是由肌肉收缩引起的机械负荷，肌肉收缩开始于子宫或卵内。以前的研究表明，在人类骨骼发育过程中，围产期在软骨骨骺中产生的应力分布会影响次级骨化中心的外观。使用有限元计算机模型表示出生或孵化附近的骨骼，我们表明，在脊椎动物中，软骨膜骨化显着之前endochonossification，在骨化软骨原基的机械应力的分布往往会抑制外观的第二骨化中心在长骨的两端。在代表脊椎动物的模型中，软骨内骨化与软骨膜附着保持同步，促进了次级中心的出现。次级中心的出现导致骨骺和生长板的形成，这在哺乳动物和现存蜥蜴中最常见。我们假设，基因型因素影响的相对速度和程度的软骨膜和endochondrialossification与机械表观遗传因素的相互作用，在发展的早期，占许多脊椎动物骨骼中观察到的形态差异。(C)1998年伦敦林奈学会。
In developing vertebrate long bones in which endochondral ossification occurs, it is preceded or accompanied by perichondral ossification. The speed and extent of perichondral apposition relative to endochondral ossification varies in different taxa. Perichondral ossification dominates early long bone development in extinct basal tetrapods and dinosaurs, extant bony fish, amphibians, and birds. In mammals and lizards, perichondral and endochondral ossification proceed more synchronously. One of the most important epigenetic factors in skeletogenesis is mechanical loading caused by muscle contractions which begin in utero or in ovo. It has been previously shown that the stress distributions created perinatally in the chondroepiphysis during human skeletal development can influence the appearance of secondary ossification centres. Using finite element computer models representing bones near birth or hatching, we demonstrate that in vertebrates in which perichondral ossification significantly precedes endochondral ossification, the distribution of mechanical stresses in the ossifying cartilage anlagen tends to inhibit the appearance of secondary ossification centres in the ends of long bones. In models representing vertebrates in which endochondral ossification keeps pace with perichondral apposition, the appearance of secondary centres is promoted. The appearance of secondary centres leads to the formation of bony epiphyses and growth plates, which are most common in mammals and extant lizards. We postulate that genotypic factors influencing the relative speed and extent of perichondral and endochondral ossification interact with mechanical epigenetic factors early in development to account for many of the morphological differences observed in vertebrate skeletons. (C) 1998 The Linnean Society of London.