Department of Orthodontics, College of Dentistry, The University of Iowa, Iowa City, Iowa, USA.
Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, Iowa, USA.
Orthod Craniofac Res. 2023 Dec;26 Suppl 1(Suppl 1):39-47. doi: 10.1111/ocr.12660. Epub 2023 Apr 18.
The objective of the study was to investigate differential gene expression between murine right and left maxilla-mandibular (MxMn) complexes.
Wild-type (WT) C57BL/6 embryonic (E) day 14.5 (n = 3) and 18.5 (n = 3) murine embryos.
The E14.5 and 18.5 embryos were harvested and hemi-sectioned the MxMn complexes into right and left halves in the mid-sagittal plane. We isolated total RNA using Trizol reagent and further purified using the RNA-easy kit (QIAGEN). We confirmed equal expression of house-keeping genes in right and left halves using RT-PCR and then performed paired-end whole mRNA sequencing in LC Sciences (Houston, TX) followed by differential transcript analyses (>1 or <-1 log fold change; p < .05; q < .05; and FPKM >0.5 in 2/3 samples). The Mouse Genome Informatics and Online Mendelian Inheritance in Man databases as well as gnomAD constraint scores were used to prioritize differentially expressed transcripts.
There were 19 upregulated and 19 downregulated transcripts at E14.5 and 8 upregulated and 17 downregulated transcripts at E18.5 time-points. These differentially expressed transcripts were statistically significant and shown to be associated with craniofacial phenotypes in mouse models. These transcripts also have significant gnomAD constraint scores and are enriched in biological processes critical for embryogenesis.
We identified significant differential expression of transcripts between E14.5 and 18.5 murine right and left MxMn complexes. These findings when extrapolated to humans, they may provide a biological basis for facial asymmetry. Further experiments are required to validate these findings in murine models with craniofacial asymmetry.
本研究旨在探讨小鼠左右上颌-下颌（MxMn）复合体之间差异基因表达。
野生型（WT）C57BL/6 胚胎 14.5 天（n=3）和 18.5 天（n=3）的胚胎。
E14.5 和 18.5 天的胚胎被收获，并在中矢状面将 MxMn 复合体对半切开为左右两半。我们使用 Trizol 试剂提取总 RNA，然后使用 RNAeasy 试剂盒（QIAGEN）进一步纯化。我们使用 RT-PCR 证实左右两半的管家基因表达相等，然后在 LC Sciences（休斯顿，TX）进行配对端全长 mRNA 测序，随后进行差异转录分析（>1 或<-1 log 倍变化；p<.05；q<.05；和 2/3 个样本中 FPKM >0.5）。使用 Mouse Genome Informatics 和 Online Mendelian Inheritance in Man 数据库以及 gnomAD 约束评分来优先考虑差异表达的转录本。
在 E14.5 时有 19 个上调和 19 个下调的转录本，在 E18.5 时有 8 个上调和 17 个下调的转录本。这些差异表达的转录本具有统计学意义，并与小鼠模型中的颅面表型相关。这些转录本也具有显著的 gnomAD 约束评分，并富集在对胚胎发生至关重要的生物学过程中。
我们在 E14.5 和 18.5 天的小鼠左右上颌-下颌复合体之间鉴定出显著的转录本差异表达。这些发现如果外推到人类，可能为面部不对称提供生物学基础。需要进一步的实验来验证这些在具有颅面不对称的小鼠模型中的发现。
