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Genetic variation in bitter taste receptor genes influences the foraging behavior of plateau zokor (Eospalax baileyi).

Zhao F, Zhang T, Xie J, Zhang S, Nevo E, Su J, Lin G - Ecol Evol (2016)

Bottom Line: Bitter plant selection indices (E bitter) were estimated.We also sequenced 26 candidate Tas2r genes from zokors and determined their relationships with the E bitter of their caches.Our results link Tas2r variation with food selection behavior at the population level for the first time.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Adaptation and Evolution of Plateau BiotaNorthwest Institute of Plateau BiologyChinese Academy of SciencesXining810001China; University of Chinese Academy of SciencesBeijing100049China.

ABSTRACT
The ability to detect bitter tastes is important for animals; it can help them to avoid ingesting harmful substances. Bitter taste perception is mainly mediated by bitter taste receptor proteins, which are encoded by members of the Tas2r gene family and vary with the dietary preference of a specific species. Although individuals with different genotypes differ in bitterness recognition capability, little is known about the relationship between genetic variation and food selection tendencies at the intraspecific level. In this study, we examined the relationship between genotypes and diet in plateau zokor (Eospalax baileyi), a subterranean rodent endemic to the Qinghai-Tibet Plateau that caches food for the winter. We assayed the composition and taste profile of each plant contained in temporary caches and vicinity quadrats, which were representative of selected and available food, respectively. Bitter plant selection indices (E bitter) were estimated. We also sequenced 26 candidate Tas2r genes from zokors and determined their relationships with the E bitter of their caches. We identified four key results: (1) zokors varied considerably in both bitter food preference and Tas2r sequences; (2) five genes (zTas2r115,zTas2r119,zTas2r126,zTas2r134, and zTas2r136) exhibited allelic variation that was significantly associated with E bitter; (3) synonymous SNPs, nonsynonymous SNPs, and pseudogenization are involved in the genotype-phenotype relationship; (4) the minor genotypes of zTas2r115,zTas2r134, and zTas2r136 and the major genotypes of zTas2r119 and zTas2r126 cached more bitter plants. Our results link Tas2r variation with food selection behavior at the population level for the first time.

No MeSH data available.


Related in: MedlinePlus

Population pyramid of Ebitter (selection index of bitter plants) of major and minor genotypes of the genes that have significant relationships with bitter plant selection. (A, B, and C) at DNA sequence level; (D and E) at amino acid (AA) sequence level; (F) only considering the indel site. The numbers before the major DNA/AA genotypes show the mutation sites of DNA/AA sequences; the blue and red bars show the frequency distributions of the 56 zokors with major and minor genotypes, respectively.
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ece32041-fig-0002: Population pyramid of Ebitter (selection index of bitter plants) of major and minor genotypes of the genes that have significant relationships with bitter plant selection. (A, B, and C) at DNA sequence level; (D and E) at amino acid (AA) sequence level; (F) only considering the indel site. The numbers before the major DNA/AA genotypes show the mutation sites of DNA/AA sequences; the blue and red bars show the frequency distributions of the 56 zokors with major and minor genotypes, respectively.

Mentions: Based on Mann–Whitney tests, at the DNA level, zTas2r115 (P = 0.004), zTas2r119 (P = 0.008), and zTas2r136 (P = 0.049) showed significant deviations in Ebitter values between the major genotype and other genotype(s) (Fig. 2A–C). At the AA sequence level, zTas2r126 (P = 0.028) and zTas2r136 (P = 0.003) showed significant deviations in Ebitter values between the major genotype and other genotype(s) (Table 2; Fig. 2D and E). For zTas2r134, the major genotype showed significant (P = 0.032) deviations in Ebitter values from those of the other genotypes (Fig. 2F). The mean rank values for each group of genes are listed in Table 2, which showed that (without regard to mutation type) the bitter plant acceptance levels were lower for the major genotypes of zTas2r115, zTas2r134, and zTas2r136 than for the minor genotypes. In contrast, the major genotypes of zTas2r119 and zTas2r126 had higher bitter plant acceptance levels than the minor genotypes. The genotype distributions of each zokor for each gene were listed in Table S5 (DNA level) and Table S6 (AA level).


Genetic variation in bitter taste receptor genes influences the foraging behavior of plateau zokor (Eospalax baileyi).

Zhao F, Zhang T, Xie J, Zhang S, Nevo E, Su J, Lin G - Ecol Evol (2016)

Population pyramid of Ebitter (selection index of bitter plants) of major and minor genotypes of the genes that have significant relationships with bitter plant selection. (A, B, and C) at DNA sequence level; (D and E) at amino acid (AA) sequence level; (F) only considering the indel site. The numbers before the major DNA/AA genotypes show the mutation sites of DNA/AA sequences; the blue and red bars show the frequency distributions of the 56 zokors with major and minor genotypes, respectively.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834321&req=5

ece32041-fig-0002: Population pyramid of Ebitter (selection index of bitter plants) of major and minor genotypes of the genes that have significant relationships with bitter plant selection. (A, B, and C) at DNA sequence level; (D and E) at amino acid (AA) sequence level; (F) only considering the indel site. The numbers before the major DNA/AA genotypes show the mutation sites of DNA/AA sequences; the blue and red bars show the frequency distributions of the 56 zokors with major and minor genotypes, respectively.
Mentions: Based on Mann–Whitney tests, at the DNA level, zTas2r115 (P = 0.004), zTas2r119 (P = 0.008), and zTas2r136 (P = 0.049) showed significant deviations in Ebitter values between the major genotype and other genotype(s) (Fig. 2A–C). At the AA sequence level, zTas2r126 (P = 0.028) and zTas2r136 (P = 0.003) showed significant deviations in Ebitter values between the major genotype and other genotype(s) (Table 2; Fig. 2D and E). For zTas2r134, the major genotype showed significant (P = 0.032) deviations in Ebitter values from those of the other genotypes (Fig. 2F). The mean rank values for each group of genes are listed in Table 2, which showed that (without regard to mutation type) the bitter plant acceptance levels were lower for the major genotypes of zTas2r115, zTas2r134, and zTas2r136 than for the minor genotypes. In contrast, the major genotypes of zTas2r119 and zTas2r126 had higher bitter plant acceptance levels than the minor genotypes. The genotype distributions of each zokor for each gene were listed in Table S5 (DNA level) and Table S6 (AA level).

Bottom Line: Bitter plant selection indices (E bitter) were estimated.We also sequenced 26 candidate Tas2r genes from zokors and determined their relationships with the E bitter of their caches.Our results link Tas2r variation with food selection behavior at the population level for the first time.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Adaptation and Evolution of Plateau BiotaNorthwest Institute of Plateau BiologyChinese Academy of SciencesXining810001China; University of Chinese Academy of SciencesBeijing100049China.

ABSTRACT
The ability to detect bitter tastes is important for animals; it can help them to avoid ingesting harmful substances. Bitter taste perception is mainly mediated by bitter taste receptor proteins, which are encoded by members of the Tas2r gene family and vary with the dietary preference of a specific species. Although individuals with different genotypes differ in bitterness recognition capability, little is known about the relationship between genetic variation and food selection tendencies at the intraspecific level. In this study, we examined the relationship between genotypes and diet in plateau zokor (Eospalax baileyi), a subterranean rodent endemic to the Qinghai-Tibet Plateau that caches food for the winter. We assayed the composition and taste profile of each plant contained in temporary caches and vicinity quadrats, which were representative of selected and available food, respectively. Bitter plant selection indices (E bitter) were estimated. We also sequenced 26 candidate Tas2r genes from zokors and determined their relationships with the E bitter of their caches. We identified four key results: (1) zokors varied considerably in both bitter food preference and Tas2r sequences; (2) five genes (zTas2r115,zTas2r119,zTas2r126,zTas2r134, and zTas2r136) exhibited allelic variation that was significantly associated with E bitter; (3) synonymous SNPs, nonsynonymous SNPs, and pseudogenization are involved in the genotype-phenotype relationship; (4) the minor genotypes of zTas2r115,zTas2r134, and zTas2r136 and the major genotypes of zTas2r119 and zTas2r126 cached more bitter plants. Our results link Tas2r variation with food selection behavior at the population level for the first time.

No MeSH data available.


Related in: MedlinePlus