Wise Paul M, Hansen Jonathan L, Reed Danielle R, Breslin Paul A S
Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA.
Chem Senses. 2007 Oct;32(8):749-54. doi: 10.1093/chemse/bjm042. Epub 2007 Jul 10.
Seventy-four pairs of monozygotic (identical) twins and 35 pairs of dizygotic (fraternal) twins provided recognition thresholds (modified Harris-Kalmus test) for the sourness of citric acid and the saltiness of sodium chloride during the Twins Days Festival in Twinsburg, OH. Variance components (ACE) models were applied to the data: total variation = additive genetic (A) + common environment (C) + nonshared environment (E). The best-fit model of variation in recognition thresholds for sourness included an additive genetic factor, accounting for 53% of the variance, but no common environment component. This level of heritability, on par with that of sensitivity to the bitter compounds 6-n-propylthiouracil and phenylthiocarbamide, strongly suggests that genetic factors play a larger role than shared environment in determining individual differences in recognition thresholds for sourness. In contrast, the best-fit model for saltiness recognition included a common environment component, accounting for 22% of the variance in thresholds, but no additive component. This result suggests that environment plays a larger role than genetics in determining individual differences in recognition thresholds for saltiness.
在俄亥俄州双子城举办双胞胎节期间，74对同卵双胞胎和35对异卵双胞胎接受了柠檬酸酸度和氯化钠咸度的识别阈值测试（改良哈里斯 - 卡尔穆斯测试）。方差成分（ACE）模型被应用于这些数据：总变异 = 加性遗传（A）+ 共同环境（C）+ 非共享环境（E）。酸味识别阈值变异的最佳拟合模型包含一个加性遗传因素，占方差的53%，但没有共同环境成分。这种遗传度水平与对苦味化合物6 - 正丙基硫氧嘧啶和苯硫脲的敏感性相当，强烈表明在决定酸味识别阈值的个体差异方面，遗传因素比共享环境发挥着更大的作用。相比之下，咸味识别的最佳拟合模型包含一个共同环境成分，占阈值方差的22%，但没有加性成分。这一结果表明，在决定咸味识别阈值的个体差异方面，环境比基因发挥着更大的作用。
