Molar intercuspal dimensions: Genetic input to phenotypic variation
Molar intercuspal dimensions: Genetic input to phenotypic variation
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DOI：
10.1177/154405910308200505
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发表时间：
2003-05-01
影响因子：
7.6
通讯作者：
Hughes, T
中科院分区：
文献类型：
--
作者：
Townsend, G;Richards, L;Hughes, T
分子研究表明，表观遗传事件在牙形成过程中决定内部牙釉质上皮如何折叠是重要的。由于这一折叠过程导致了臼齿尖的后续排列，我们假设人类臼齿的尖间距离比总冠直径表现出更大的表型变异，但遗传力较低。从100对同卵双胞胎和74对异卵双胞胎的牙模数字化图像中记录尖间距离和最大牙冠直径。在平均值中，尖间距离表现出较少的性别二态性，但相对变异性和波动不对称性比整体冠测量更大。齿间距离与整体冠度的相关性较低。只考虑环境影响的模式解释了在几个尖间测量中观察到的变化。对于具有显著加性遗传变异的穗间变量，估计遗传率在43% ~ 79%之间，而总体冠大小的遗传率一般较高，在60% ~ 82%之间。我们发现齿间距离的高表型变异只有适度的遗传贡献，这与在初级和次级牙釉质结形成后，内部牙釉质上皮的进行性折叠受到大量表观遗传影响是一致的。
Molecular studies indicate that epigenetic events are important in determining how the internal enamel epithelium folds during odontogenesis. Since this process of folding leads to the subsequent arrangement of cusps on molar teeth, we hypothesized that intercuspal distances of human molar teeth would display greater phenotypic variation but lower heritabilities than overall crown diameters. Intercuspal distances and maximum crown diameters were recorded from digitized images of dental casts in 100 monozygotic and 74 dizygotic twin pairs. Intercuspal distances displayed less sexual dimorphism in mean values but greater relative variability and fluctuating asymmetry than overall crown measures. Correlations between intercuspal distances and overall crown measures were low. Models incorporating only environmental effects accounted for observed variation in several intercuspal measures. For those intercuspal variables displaying significant additive genetic variance, estimates of heritability ranged from 43 to 79%, whereas those for overall crown size were higher generally, ranging from 60 to 82%. Our finding of high phenotypic variation in intercuspal distances with only moderate genetic contribution is consistent with substantial epigenetic influence on the progressive folding of the internal enamel epithelium, following formation of the primary and secondary enamel knots.