The Institute of Biochemistry, Food Science and Nutrition, The Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
The Koret School of Veterinary Medicine, The Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
Front Endocrinol (Lausanne). 2023 Jun 12;14:1127536. doi: 10.3389/fendo.2023.1127536. eCollection 2023.
Both the calvarial and the cortical bones develop through intramembranous ossification, yet they have very different structures and functions. The calvaria enables the rapid while protected growth of the brain, whereas the cortical bone takes part in locomotion. Both types of bones undergo extensive modeling during embryonic and post-natal growth, while bone remodeling is the most dominant process in adults. Their shared formation mechanism and their highly distinct functions raise the fundamental question of how similar or diverse the molecular pathways that act in each bone type are.
To answer this question, we aimed to compare the transcriptomes of calvaria and cortices from 21-day old mice by bulk RNA-Seq analysis.
The results revealed clear differences in expression levels of genes related to bone pathologies, craniosynostosis, mechanical loading and bone-relevant signaling pathways like WNT and IHH, emphasizing the functional differences between these bones. We further discussed the less expected candidate genes and gene sets in the context of bone. Finally, we compared differences between juvenile and mature bone, highlighting commonalities and dissimilarities of gene expression between calvaria and cortices during post-natal bone growth and adult bone remodeling.
Altogether, this study revealed significant differences between the transcriptome of calvaria and cortical bones in juvenile female mice, highlighting the most important pathway mediators for the development and function of two different bone types that originate both through intramembranous ossification.
颅骨和皮质骨都通过膜内成骨发育，但它们具有非常不同的结构和功能。颅骨使大脑能够快速而受保护地生长，而皮质骨则参与运动。这两种类型的骨骼在胚胎和产后生长过程中都经历了广泛的塑造，而骨重塑是成年人中最主要的过程。它们共同的形成机制和高度不同的功能提出了一个基本问题，即在每种骨骼类型中起作用的分子途径是相似还是不同。
为了回答这个问题，我们旨在通过批量 RNA-Seq 分析比较 21 天大的小鼠颅骨和皮质的转录组。
结果显示，与骨病理学、颅缝早闭、机械加载以及骨相关信号通路（如 WNT 和 IHH）相关的基因的表达水平存在明显差异，强调了这些骨骼之间的功能差异。我们进一步讨论了在骨背景下不太预期的候选基因和基因集。最后，我们比较了幼年和成熟骨骼之间的差异，突出了在产后骨骼生长和成人骨重塑过程中颅骨和皮质之间基因表达的共性和差异。
总的来说，这项研究揭示了幼年雌性小鼠颅骨和皮质转录组之间的显著差异，突出了两种不同骨骼类型发育和功能的最重要的途径调节剂，它们都起源于膜内成骨。
