Bitter taste reception is presumably associated with dietary selection,preventing animals from ingesting potentially harmful compounds.Accordingly,carnivores,who encounter these toxic substances less often,should have...Bitter taste reception is presumably associated with dietary selection,preventing animals from ingesting potentially harmful compounds.Accordingly,carnivores,who encounter these toxic substances less often,should have fewer genes associated with bitter taste reception compared with herbivores and omnivores.To investigate the genetic basis of bitter taste reception,we confirmed bitter taste receptor(T2R)genes previously found in the genome sequences of two herbivores(cow and horse),two omnivores(mouse and rat)and one carnivore(dog).We also identified,for the first time,the T2R repertoire from the genome of other four carnivore species(ferret,giant panda,polar bear and cat)and detected 17−20 bitter receptor genes from the five carnivore genomes,including 12−16 intact genes,0−1 partial but putatively functional genes,and 3−8 pseudogenes.Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species,supporting earlier speculations that carnivores have fewer T2R genes,herbivores an intermediate number,and omnivores the largest T2R gene repertoire.To further explain the genetic basis for this disparity,we constructed a phylogenetic tree,which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree,suggesting that carnivore T2Rs were conserved among mammals.Similarly,the small carnivore T2R family size was likely due to rare duplication events.Collectively,these results strengthen arguments for the connection between T2R gene family size,diet and habit.展开更多
Bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. Accordingly, carnivores, who encounter these toxic substances less often, should...Bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. Accordingly, carnivores, who encounter these toxic substances less often, should have fewer genes associated with bitter taste reception compared with herbivores and omnivores. To investigate the genetic basis of bitter taste reception, we confirmed bitter taste receptor （T2R） genes previously found in the genome sequences of two herbivores （cow and horse）, two omnivores （mouse and rat） and one carnivore （dog）. We also identified, for the first time, the T2R repertoire from the genome of other four carnivore species （ferret, giant panda, polar bear and cat） and detected 17-20 bitter receptor genes from the five carnivore genomes, including 12-16 intact genes, 0-1 partial but putatively functional genes, and 3-8 pseudogenes. Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species, supporting earlier speculations that carnivores have fewer T2R genes, herbivores an intermediate number, and onmivores the largest T2R gene repertoire. To further explain the genetic basis for this disparity, we constructed a phylogenetic tree, which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree, suggesting that carnivore T2Rs were conserved among mammals. Similarly, the small carnivore T2R family size was likely due to rare duplication events. Collectively, these results strengthen arguments for the connection between T2R gene family size, diet and habit.展开更多
本文首先简单介绍全数字化T/R组件应用场景,然后详细阐述了全数字化T/R组件发射通道的工作原理及关键技术,主要是直接数字合成技术(direct Digital Synthesize,DDS),之后提出了一种L波段(5.3GHz~5.9GHz)数字化T/R组件方案并给出原理框图...本文首先简单介绍全数字化T/R组件应用场景,然后详细阐述了全数字化T/R组件发射通道的工作原理及关键技术,主要是直接数字合成技术(direct Digital Synthesize,DDS),之后提出了一种L波段(5.3GHz~5.9GHz)数字化T/R组件方案并给出原理框图;再重点分析全数字化T/R组件发射通道的设计,包括:信道模块、发射前端、数字及控制单元设计,并出于一体化设计的考虑简单介绍了射频接收前端的设计思想;最后,对整个系统进行调测试,给出了实物照片和测试数据,测试结果表明该数字化T/R组件发射通道参数:工作带宽5.3GHz~5.9GHz,调制带宽1MHz~5MHz,移相范围0o~360o,最大衰减量15dB,最大输出峰值功率50W,最大工作占空比25%,杂散抑制大于60dBc,达到了指标要求,验证了数字化T/R组件发射通道的性能。展开更多
基金This work was supported by the Key Project(30930015)General Project(31271329)from National Natural Science Foundation of China。
文摘Bitter taste reception is presumably associated with dietary selection,preventing animals from ingesting potentially harmful compounds.Accordingly,carnivores,who encounter these toxic substances less often,should have fewer genes associated with bitter taste reception compared with herbivores and omnivores.To investigate the genetic basis of bitter taste reception,we confirmed bitter taste receptor(T2R)genes previously found in the genome sequences of two herbivores(cow and horse),two omnivores(mouse and rat)and one carnivore(dog).We also identified,for the first time,the T2R repertoire from the genome of other four carnivore species(ferret,giant panda,polar bear and cat)and detected 17−20 bitter receptor genes from the five carnivore genomes,including 12−16 intact genes,0−1 partial but putatively functional genes,and 3−8 pseudogenes.Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species,supporting earlier speculations that carnivores have fewer T2R genes,herbivores an intermediate number,and omnivores the largest T2R gene repertoire.To further explain the genetic basis for this disparity,we constructed a phylogenetic tree,which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree,suggesting that carnivore T2Rs were conserved among mammals.Similarly,the small carnivore T2R family size was likely due to rare duplication events.Collectively,these results strengthen arguments for the connection between T2R gene family size,diet and habit.
基金supported by the Key Project (30930015)General Project (31271329) from National Natural Science Foundation of China
文摘Bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. Accordingly, carnivores, who encounter these toxic substances less often, should have fewer genes associated with bitter taste reception compared with herbivores and omnivores. To investigate the genetic basis of bitter taste reception, we confirmed bitter taste receptor （T2R） genes previously found in the genome sequences of two herbivores （cow and horse）, two omnivores （mouse and rat） and one carnivore （dog）. We also identified, for the first time, the T2R repertoire from the genome of other four carnivore species （ferret, giant panda, polar bear and cat） and detected 17-20 bitter receptor genes from the five carnivore genomes, including 12-16 intact genes, 0-1 partial but putatively functional genes, and 3-8 pseudogenes. Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species, supporting earlier speculations that carnivores have fewer T2R genes, herbivores an intermediate number, and onmivores the largest T2R gene repertoire. To further explain the genetic basis for this disparity, we constructed a phylogenetic tree, which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree, suggesting that carnivore T2Rs were conserved among mammals. Similarly, the small carnivore T2R family size was likely due to rare duplication events. Collectively, these results strengthen arguments for the connection between T2R gene family size, diet and habit.
文摘本文首先简单介绍全数字化T/R组件应用场景,然后详细阐述了全数字化T/R组件发射通道的工作原理及关键技术,主要是直接数字合成技术(direct Digital Synthesize,DDS),之后提出了一种L波段(5.3GHz~5.9GHz)数字化T/R组件方案并给出原理框图;再重点分析全数字化T/R组件发射通道的设计,包括:信道模块、发射前端、数字及控制单元设计,并出于一体化设计的考虑简单介绍了射频接收前端的设计思想;最后,对整个系统进行调测试,给出了实物照片和测试数据,测试结果表明该数字化T/R组件发射通道参数:工作带宽5.3GHz~5.9GHz,调制带宽1MHz~5MHz,移相范围0o~360o,最大衰减量15dB,最大输出峰值功率50W,最大工作占空比25%,杂散抑制大于60dBc,达到了指标要求,验证了数字化T/R组件发射通道的性能。
