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Wang W, Ge J, Zhang Y, Zhang J. The male's scent triggered a neural response in females despite ambiguous behavioral response in Asian house rats. Integr Zool 2024; 19:694-709. [PMID: 37804522 DOI: 10.1111/1749-4877.12768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/09/2023]
Abstract
Pheromones and olfactory communication play vital roles in sex recognition and mate choice in rodents. Asian house rats (Rattus tanezumi) (RT) often startle easily, making behavioral measurements difficult to carry out accurately in the laboratory. Here, the behavioral and olfactory preferences of the female RT between males and females were not observed using a conventional two-choice device; we then explored the neuro-immunohistochemical evidence in the brains of RT females. We found that male urine elicited significantly higher c-fos expression in the accessory olfactory system and sex-related brain regions in females than female urine did. On the other hand, the differences of volatile compounds and major urinary proteins (MUPs) in both voided urine and preputial glands (PGs) of the RT were detected using gas chromatography-mass spectrometer, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing electrophoresis, and liquid chromatography-electrospray ionization mass spectrometry. We found that PG-derived 1-(4,5-dihydro-2-thiazolyl)-ethanone and total MUPs were more abundant in males versus females, suggesting these sexually divergent components might activate the female's accessory olfactory system. In conclusion, the neuro-immunohistochemical evidence indicated that potential sex pheromones might exist in RT; however, the strength of the chemical signal might be too weak to cause behavioral responses in females.
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Affiliation(s)
- Weichao Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Jingru Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Yaohua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jianxu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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Zhang YH, Zhao L, Zhang MY, Cao RD, Hou GM, Teng HJ, Zhang JX. Fatty acid metabolism decreased while sexual selection increased in brown rats spreading south. iScience 2023; 26:107742. [PMID: 37731619 PMCID: PMC10507208 DOI: 10.1016/j.isci.2023.107742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/27/2023] [Accepted: 08/24/2023] [Indexed: 09/22/2023] Open
Abstract
For mammals that originate in the cold north, adapting to warmer environments is crucial for southwards invasion. The brown rat (Rattus norvegicus) originated in Northeast China and has become a global pest. R. n. humiliatus (RNH) spread from the northeast, where R. n. caraco (RNC) lives, to North China and diverged to form a subspecies. Genomic analyses revealed that subspecies differentiation was promoted by temperature but impeded by gene flow and that genes related to fatty acid metabolism were under the strongest selection. Transcriptome analyses revealed downregulated hepatic genes related to fatty acid metabolism and upregulated those related to pheromones in RNH vs. RNC. Similar patterns were observed in relation to cold/warm acclimation. RNH preferred mates with stronger pheromone signals intra-populationally and more genetic divergence inter-populationally. We concluded that RNH experienced reduced fat utilization and increased pheromone-mediated sexual selection during its invasion from the cold north to warm south.
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Affiliation(s)
- Yao-Hua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China
| | - Lei Zhao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ming-Yu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui-Dong Cao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guan-Mei Hou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hua-Jing Teng
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Jian-Xu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beichen West Road 1-5, Chaoyang District, Beijing 100101, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
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Zhang YH, Zhao L, Fu SH, Wang ZS, Zhang JX. Male pheromones and their reception by females are co-adapted to affect mating success in two subspecies of brown rats. Curr Zool 2021; 67:371-382. [PMID: 34671704 PMCID: PMC8521721 DOI: 10.1093/cz/zoaa066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 10/12/2020] [Indexed: 12/03/2022] Open
Abstract
Pheromonal communication plays a key role in the sociosexual behavior of rodents. The coadaptation between pheromones and chemosensory systems has been well illustrated in insects but poorly investigated in rodents and other mammals. We aimed to investigate whether coadaptation between male pheromones and female reception might have occurred in brown rats Rattus norvegicus. We recently reported that major urinary protein (MUP) pheromones are associated with male mating success in a brown rat subspecies, R. n. humiliatus (Rnh). Here, we discovered that MUPs were less polymorphic and occurred at much lower concentrations in males of a parapatric subspecies, R. n. caraco (Rnc), than in Rnh males, and found no association between pheromones and paternity success. Moreover, the observation of Rnc males that experienced chronic dyadic encounters and established dominance–submission relationships revealed that the dominant males achieved greater mating success than the subordinate males, but their MUP levels did not differ by social status. These findings suggest that male mating success in Rnc rats is related to social rank rather than to pheromone levels and that low concentration of MUPs might not be a reliable signal for mate choice in Rnc rats, which is different from the findings obtained in Rnh rats. In addition, compared with Rnh females, Rnc females exhibited reduced expression of pheromone receptor genes, and a lower number of vomeronasal receptor neurons were activated by MUP pheromones, which imply that the female chemosensory reception of pheromones might be structurally and functionally coadapted with male pheromone signals in brown rats.
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Affiliation(s)
- Yao-Hua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Lei Zhao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shi-Hui Fu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,College of Life Science, Hebei University, Hebei Province, Baoding 071002, China
| | - Zhen-Shan Wang
- College of Life Science, Hebei University, Hebei Province, Baoding 071002, China
| | - Jian-Xu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
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Zhang YH, Tang MM, Guo X, Gao XR, Zhang JH, Zhang JX. Associative learning is necessary for airborne pheromones to activate sexual arousal-linked brain areas of female rats. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2685-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Sex pheromone levels are associated with paternity rate in brown rats. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-018-2627-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Guo X, Guo H, Zhao L, Zhang YH, Zhang JX. Two predominant MUPs, OBP3 and MUP13, are male pheromones in rats. Front Zool 2018; 15:6. [PMID: 29483934 PMCID: PMC5824612 DOI: 10.1186/s12983-018-0254-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 02/02/2018] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND In rats, urine-borne male pheromones comprise organic volatile compounds and major urinary proteins (MUPs). A number of volatile pheromones have been reported, but no MUP pheromones have been identified in rat urine. RESULTS We used sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing electrophoresis (IEF), nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS) after in gel digestion of the proteins and quantitative real-time PCR (qRT-PCR) and showed that the levels of two MUPs, odorant-binding protein 3 (OBP3) (i.e. PGCL4) and MUP13 (i.e. PGCL1), in urine and their mRNAs in liver were higher in males than in females and were suppressed by orchidectomy and restored by testosterone treatment (T treatment). We then generated recombinant MUPs (rMUPs) and found that the sexual attractiveness of urine from castrated males to females significantly increased after the addition of either recombinant OBP3 (rOBP3) or recombinant MUP13 (rMUP13). Using c-Fos immunohistochemistry, we further examined neuronal activation in the brains of female rats after they sniffed rOBP3 or rMUP13. Both rOBP3 and rMUP13 activated the accessory olfactory bulb (AOB), medial preoptic area (MPA), bed nucleus of the stria terminalis (BST), medial amygdala (MeA), posteromedial cortical amygdala (PMCo) and ventromedial nucleus of the hypothalamus (VMH), which participate in the neural circuits responsible for pheromone-induced sexual behaviours. In particular, more c-Fos-immunopositive (c-Fos-ir) cells were observed in the posterior AOB than in the anterior AOB. CONCLUSIONS The expression of OBP3 and MUP13 was male-biased and androgen-dependent. They attracted females and activated brain areas related to sexual behaviours in female rats, suggesting that both OBP3 and MUP13 are male pheromones in rats. Particularly, an OBP excreted into urine was exemplified to be a chemical signal.
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Affiliation(s)
- Xiao Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichen West Road, Beijing, 100101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Huifen Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichen West Road, Beijing, 100101 China
| | - Lei Zhao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichen West Road, Beijing, 100101 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Yao-Hua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichen West Road, Beijing, 100101 China
| | - Jian-Xu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, 1-5 Beichen West Road, Beijing, 100101 China
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Guo HL, Teng HJ, Zhang JH, Zhang JX, Zhang YH. Asian house rats may facilitate their invasive success through suppressing brown rats in chronic interaction. Front Zool 2017; 14:20. [PMID: 28413431 PMCID: PMC5389004 DOI: 10.1186/s12983-017-0202-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 03/02/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The Asian house rat (Rattus tanezumi) and the brown rat (Rattus norvegicus) are closely related species and are partially sympatric in southern China. Over the past 20 years, R. tanezumi has significantly expanded northward in China and partially replaced the native brown rat subspecies, R. n. humiliatus. Although invasive species are often more aggressive than native species, we did not observe interspecific physical aggression between R. tanezumi and R. n. humiliatus. Here, we focused on whether or not R. tanezumi was superior to R. n. humiliatus in terms of nonphysical competition, which is primarily mediated by chemical signals. RESULTS We performed two laboratory experiments to test different paradigms in domesticated R. tanezumi and R. n. humiliatus. In Experiment 1, we caged adult male rats of each species for 2 months in heterospecific or conspecific pairs, partitioned by perforated galvanized iron sheets, allowing exchange of chemical stimuli and ultrasonic vocalization. The sexual attractiveness of male urine odor showed a tendency (marginal significance) to increase in R. tanezumi caged with R. n. humiliatus, compared with those in conspecific pairs. Hippocampal glucocorticoid receptor (GR) and brain-derived nutrition factor (BDNF) mRNA were upregulated in R. n. humiliatus and R. tanezumi, respectively, when the rats were caged in heterospecific pairs. In Experiment 2, we kept juvenile male rats in individual cages in rooms with either the same or the different species for 2 months, allowing chemical interaction. The sexual attractiveness of male urine was significantly enhanced in R. tanezumi, but reduced in R. n. humiliatus by heterospecific cues and mRNA expression of hippocampal GR and BDNF were upregulated by heterospecific cues in R. n. humiliatus and R. tanezumi, respectively. Although not identical, the results from Experiments 1 and 2 were generally consistent. CONCLUSIONS The results of both experiments indicate that nonphysical/chronic interspecific stimuli, particularly scent signals, between R. n. humiliatus and R. tanezumi may negatively affect R. n. humiliatus and positively affect R. tanezumi. We infer that chronic interspecific interactions may have contributed to the invasion of R. tanezumi into the range of R. n. humiliatus in natural habitats.
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Affiliation(s)
- Hong-Ling Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, No.1-5 Beichen West Road, Chaoyang District, Beijing, 100101 China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Hua-Jing Teng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, No.1-5 Beichen West Road, Chaoyang District, Beijing, 100101 China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jin-Hua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, No.1-5 Beichen West Road, Chaoyang District, Beijing, 100101 China
| | - Jian-Xu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, No.1-5 Beichen West Road, Chaoyang District, Beijing, 100101 China
| | - Yao-Hua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, No.1-5 Beichen West Road, Chaoyang District, Beijing, 100101 China
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Zhang YH, Liang HC, Guo HL, Zhang JX. Exaggerated male pheromones in rats may increase predation cost. Curr Zool 2016; 62:431-437. [PMID: 29491932 PMCID: PMC5804251 DOI: 10.1093/cz/zow047] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 03/28/2016] [Indexed: 11/15/2022] Open
Abstract
Male animals with more conspicuous visual and acoustic signals increase their mating success, but also increase the risk of being attacked by eavesdropping predators. In rodents, males with richer sex pheromones often have higher attractiveness to females, but whether or not the males are also at higher predation risk is poorly known. Here, we used 2 laboratory inbred strains of the rat Rattus norvegicus, Brown Norway (BN) and Lewis (LEW), and wild-captured rats as odor donors to assess the relationship between the pheromone levels in male rats and attractiveness to domestic cats Felis catus. LEW rats had significantly higher levels of male pheromones (e.g., 4-heptanone, 2-heptanone, and 9-hydroxy-2-nonanone) than BN rats. Simultaneously, wild-captured male rats were selectively assigned to 2 groups (HIGH or LOW) based on pheromone content as determined by gas chromatography–mass spectrometry (GC-MS). Binary choice tests were carried out during the night in the test room. We found that cats spent more time investigating male bedding and urine of LEW rats than the counterpart of BN rats. Likewise, cats also preferred bedding and urine odor of the HIGH wild rats compared with the counterparts of LOW wild rats. Adding synthetic analogs of the 3 pheromone ketones into the urine of either BN rats or LOW wild rats significantly increased their attractiveness to cats. Our data suggest that the rats with exaggerated male pheromones more strongly attracted predators and thus as a consequence may suffer from elevated predation risk.
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Affiliation(s)
- Yao-Hua Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hong-Chun Liang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,College of Horticulture and Landscape, Tianjin Agricultural University, Tianjin 300384, China, and
| | - Hong-Ling Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian-Xu Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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