哺乳动物对鲜味和甜味的感觉，是通过味觉受体TAS1Rs蛋白家族来实现的。TAS1R1与TAS1R3组成的二聚体感受鲜味物质，TAS1R2与TAS1R3二聚体感受甜味物质。前期研究表明编码TAS1Rs蛋白基因外显子的异义突变会导致蛋白序列的变化，导致感受刺激物范围的变化，或者是味觉灵敏度的差异。猴科(Cercopithecidae)内部食性差异非常显著，猴亚科主食肉和果，而疣猴亚科主食叶，自然选择对其甜味和鲜味受体蛋白的选择压力可能会出现明显变化,编码基因的突变也可能导致受体蛋白敏感度或感受刺激物范围的变化。本项目计划克隆猴科各个属代表物种的TAS1R1、TAS1R2、TAS1R3的编码区序列，构建表达载体，在HEK细胞系中进行表达，检测不同刺激物浓度下敏感度差异，并通过行为学测试验证不同物种对鲜味和鲜味剂的偏好性。从而揭示猴亚科和疣猴亚科味觉受体蛋白的适应性进化过程及与食性的相关性。

In mammals, sweet and umami taste perception is conferred by taste receptor cells through the use of G protein-coupled receptors (GPCRs) TAS1Rs which were encoded by gene family of Tas1rs genes. The TAS1R1 protein forms a heterodimer with TAS1R3 to form a two-part umami taste receptor, meanwhile the TAS1R2+TAS1R3 heterodimer functions as the sweetness receptor. TAS1R proteins are characteristic of seven domains spanning the plasma membrane. The TAS1R proteins consist of about 850 amino acids and have a large extracellular N-terminus. The gene structure of tas1rs family is believed to be conserved among species.In recent year, analyses on umami and sweet taste receptors have been conducted in number of species. Tas1r1 is found to be pseudogenized in the giant panda (family Ursidae), which is herbivorous. Additionally, tas1r2 were revealed to be inactivated in the cat family Felidae, vampire bats, horse, chicken, zebra finch and western clawed frog. However, the ecological causes of pseudogenization of tas1r genes are unclear.We choose to study the evolution of the sweet and umami taste receptor gene tas1rs in Cercopithecidae species because they exhibit a wide range of diets. Within the family Cercopithecidae, subfamily Colobinae is also known as leaf-monkeys and feed predominantly on relatively low-energy leaves, while another subfamily Cercopithecinae feed predominantly on relatively high-energy foods such as fruits, seeds, insects, and other vertebrates.The difference on food type between close-related subfamilies means significant variation of the selective press on taste genes. In this study, we plan to get the sequences of tas1rs gene of species in Cercopitheciade and functionally expressed these taste receptor variants. We plan to analyze their cellular response using an in vitro cellular assay.The main goal are to: (1)calculate the nonsynonymous/synonymous substitution rate ratio (ω = dN/dS) which measures the selective pressure at the protein level,(2)find the fuctionanl varition among taste receptors in Cercopithecidae species with different food favor,(3)measure behavioral preference to sweet and umami liquid in different species .