The repertoire of bitter taste receptor genes in canids
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Bitter taste receptors (Tas2rs) play important roles in mammalian defense mechanisms by helping animals detect and avoid toxins in food. Although Tas2r genes have been widely studied in several mammals, minimal research has been performed in canids. To analyze the genetic basis of Tas2r genes in canids, we first identified Tas2r genes in the wolf, maned wolf, red fox, corsac fox, Tibetan fox, fennec fox, dhole and African hunting dog. A total of 183 Tas2r genes, consisting of 118 intact genes, 6 partial genes and 59 pseudogenes, were detected. Differences in the pseudogenes were observed among nine canid species. For example, Tas2r4 was a pseudogene in the dog but might play a functional role in other canid species. The Tas2r42 and Tas2r10 genes were pseudogenes in the maned wolf and dhole, respectively, and the Tas2r5 and Tas2r34 genes were pseudogenes in the African hunting dog; however, these genes were intact genes in other canid species. The differences in Tas2r pseudogenes among canids might suggest that the loss of intact Tas2r genes in canid species is species-dependent. We further compared the 183 Tas2r genes identified in this study with Tas2r genes from ten additional carnivorous species to evaluate the potential influence of diet on the evolution of the Tas2r gene repertoire. Phylogenetic analysis revealed that most of the Tas2r genes from the 18 species intermingled across the tree, suggesting that Tas2r genes are conserved among carnivores. Within canids, we found that some Tas2r genes corresponded to the traditional taxonomic groupings, while some did not. PIC analysis showed that the number of Tas2r genes in carnivores exhibited no positive correlation with diet composition, which might be due to the limited number of carnivores included in our study.
KeywordsBitter taste receptor gene Tas2r Canid species Phylogenetic analysis PIC
Bitter taste receptor
Polymerase chain reaction
Phylogenetically independent contrasts
This study was supported by the following grants: the Special Fund for Forest Scientific Research in the Public Welfare (No. 201404420) and the National Natural Science Fund of China (Nos. 31372220, 31172119).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
This research was approved by the Qufu Normal University Institutional Animal Care and Use Committee (permit number: QFNU2015-003). The fur samples were obtained from specimens. All of the blood samples were obtained during routine health monitoring. This study caused no harm to the seven canid species, and its results may help us to better protect these animals.
Informed consent was obtained from all individual participants included in the study.
- Hillier LWM, Birney E, Warren W, Hardison RC, Ponting CP, Bork P, Burt DW, Groenen MA, Delany ME, Dodgson JB (2004) Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution. Nature 432:695–716. doi: 10.1038/nature03154
- Liu Z, Liu G, Hailer F, Orozco-Terwengel P, Tan X, Tian J, Yan Z, Zhang B, Ming L (2016) Dietary specialization drives multiple independent losses and gains in the bitter taste gene repertoire of Laurasiatherian mammals. Front Zool 13:28. doi: 10.1186/s12983-016-0161-1 CrossRefPubMedPubMedCentralGoogle Scholar
- Monteiro Ferreira A, Tomas Marques A, Bhide M, Cubric-Curik V, Hollung K, Knight CH, Raundrup K, Lippolis J, Palmer M, Sales-Baptista E, Araujo SS, de Almeida AM (2015) Sequence analysis of bitter taste receptor gene repertoires in different ruminant species. PLoS One 10:e0124933. doi: 10.1371/journal.pone.0124933 CrossRefPubMedPubMedCentralGoogle Scholar
- Wang X, Tedford RH, Taylor BE (1999) Phylogenetic systematics of the Borophaginae (Carnivora, Canidae). Bull Am Mus Nat Hist 243:1–391Google Scholar
- Wang GD, Zhai W, Yang HC, Wang L, Zhong L, Liu YH, Fan RX, Yin TT, Zhu CL, Poyarkov AD, Irwin DM, Hytonen MK, Lohi H, Wu CI, Savolainen P, Zhang YP (2016) Out of southern East Asia: the natural history of domestic dogs across the world. Cell Res 26:21–33. doi: 10.1038/cr.2015.147 CrossRefPubMedGoogle Scholar