Search Results (12)

Conflicts between humans and Japanese macaques (Macaca fuscata) have intensified due to urban and agricultural expansion, reducing natural habitats and pushing macaques into human settlements. This review examines strategies for managing human–macaque coexistence in Japan. Since the 1970s, urbanisation and deforestation have led to increased macaque migration into populated areas, resulting in property damage, crop loss, and, in some cases, aggressive encounters. The growing macaque population underscores the urgency of effective management programmes. Strategies include preventive measures, such as weeding to limit food sources, habitat modification, and community-based interventions to reduce attractants. Non-lethal deterrents, including visual and auditory scare tactics, trained guard animals, and electric fences, have been implemented to discourage macaques from entering human spaces. Physical barriers, such as fences and buffer zones, provide long-term mitigation but require maintenance and community cooperation. Fertility control, including sterilisation and hormonal contraception, offers a long-term population management solution but presents logistical challenges. Lethal control and capture-relocation, though controversial, remain options for particularly problematic individuals. Additionally, integrating One Health and One Conservation approaches into macaque management allows for a holistic strategy that considers disease risks, ecological balance, and ethical implications. A balanced management plan that incorporates multiple strategies, community participation, and continuous monitoring is crucial for mitigating conflicts and fostering sustainable coexistence between humans and macaques. Full article

Huddling behaviour is observed across various mammalian and avian species. Huddling, a behaviour wherein animals maintain close physical contact with conspecifics for warmth and social bonding, is widely documented among species in cold environments as a crucial thermoregulatory mechanism. Interestingly, on Shodoshima, Japanese macaques form exceptionally large huddling clusters, often exceeding 50 individuals, a significant deviation from the smaller groups observed in other populations (Arashyama, Katsuyama, and Taksakiyama) and climates. This study aims to uncover the mechanisms behind the formation and size of these huddling clusters, proposing that such behaviours can be explained by simple probabilistic rules influenced by environmental conditions, the current cluster size, and individual decisions. Employing a computational model developed in Netlogo, we seek to demonstrate how emergent properties like the formation and dissolution of clusters arise from collective individual actions. We investigate whether the observed differences in huddling behaviour, particularly the larger cluster sizes on Shodoshima compared to those in colder habitats, reflect variations in social tolerance and cohesion. The model incorporates factors such as environmental temperature, cluster size, and individual decision-making, offering insights into the adaptability of social behaviours under environmental pressures. The findings suggest that temperature plays a crucial role in influencing huddling behaviour, with larger clusters forming in colder climates as individuals seek warmth. However, the study also highlights the importance of joining and leaving a cluster in terms of probability in the dynamics of huddling behaviour. We discussed the large clusters on Shodoshima as a result of a combination of environmental factors and a unique social tolerance and cohesion among the macaques. This study contributes to our understanding of complex social phenomena through the lens of self-organisation, illustrating how simple local interactions can give rise to intricate social structures and behaviours. Full article

Circoviruses (CVs) and cycloviruses (CyVs), members of the family Circoviridae, have been identified only occasionally in non-human primates (NHPs). In this study, we investigated the presence and genetic features of these viruses in 48 NHPs housed in the Bioparco—Rome Zoological Garden (Italy) and in the Anima Natura Wild Sanctuary Semproniano (Grosseto, Italy), testing fecal, saliva, and serum samples with a broadly reactive consensus nested PCR able of amplifying a partial region of the replicase (Rep) gene of members of the family Circoviridae. Viral DNA was detected in a total of 10 samples, including a saliva swab and 9 fecal samples collected, respectively from five Japanese macaques (Macaca fuscata) and four mandrills (Mandrillus sphinx), with an overall prevalence of 18.7% (9/48). On genome sequencing, five strains revealed the highest nucleotide identity (98.3–98.6%) to a CyV strain (RI196/ITA) detected in the intestinal content of a Maltese wall lizard (Podarcis filfolensis) in Italy. Although the origin of the Italian NHP strains, genetically distant from previously detected NHP CyVs, is uncertain, our results also highlight that the virome of captive animals is modulated by the different dietary and environmental sources of exposure. Full article

The P2X7 receptor is a trimeric ligand-gated cation channel activated by extracellular adenosine 5′-triphosphate. The study of animals has greatly advanced the investigation of P2X7 and helped to establish the numerous physiological and pathophysiological roles of this receptor in human health and disease. Following a short overview of the P2X7 distribution, roles and functional properties, this article discusses how animal models have contributed to the generation of P2X7-specific antibodies and nanobodies (including biologics), recombinant receptors and radioligands to study P2X7 as well as to the pharmacokinetic testing of P2X7 antagonists. This article then outlines how mouse and rat models have been used to study P2X7. These sections include discussions on preclinical disease models, polymorphic P2X7 variants, P2X7 knockout mice (including bone marrow chimeras and conditional knockouts), P2X7 reporter mice, humanized P2X7 mice and P2X7 knockout rats. Finally, this article reviews the limited number of studies involving guinea pigs, rabbits, monkeys (rhesus macaques), dogs, cats, zebrafish, and other fish species (seabream, ayu sweetfish, rainbow trout and Japanese flounder) to study P2X7. Full article

Human T-cell leukemia virus type 1 (HTLV-1) causes serious and intractable diseases in some carriers after infection. The elimination of infected cells is considered important to prevent this onset, but there are currently no means by which to accomplish this. We previously developed “virotherapy”, a therapeutic method that targets and kills HTLV-1-infected cells using a cytolytic recombinant vesicular stomatitis virus (rVSV). Infection with rVSV expressing an HTLV-1 primary receptor elicits therapeutic effects on HTLV-1-infected envelope protein (Env)-expressing cells in vitro and in vivo. Simian T-cell leukemia virus type 1 (STLV-1) is closely related genetically to HTLV-1, and STLV-1-infected Japanese macaques (JMs) are considered a useful HTLV-1 surrogate, non-human primate model in vivo. Here, we performed an in vitro drug evaluation of rVSVs against STLV-1 as a preclinical study. We generated novel rVSVs encoding the STLV-1 primary receptor, simian glucose transporter 1 (JM GLUT1), with or without an AcGFP reporter gene. Our data demonstrate that these rVSVs specifically and efficiently infected/eliminated the STLV-1 Env-expressing cells in vitro. These results indicate that rVSVs carrying the STLV-1 receptor could be an excellent candidate for unique anti-STLV-1 virotherapy; therefore, such antivirals can now be applied to STLV-1-infected JMs to determine their therapeutic usefulness in vivo. Full article

Development of effective in vitro human lip models, specific to the vermilion epithelium, has not progressed as much as that of skin and oral mucosa/gingiva models in vitro. Our histologic examination demonstrated that a Japanese macaque (male, 7 years and 9 months old) had vermilion in the lip distinct from adjacent skin and oral mucosa, resembling histological characteristics of the human lip. Therefore, in this study, we examined the gene expression profile of the three distinct epithelia (skin/vermilion/oral mucosa) within the lip of a Japanese macaque to explore a single potential marker of human vermilion epithelium. Six pairwise comparisons in the skin/vermilion/oral mucosa epithelium in vitro and in vivo revealed 69 differentially up-regulated genes in vermilion epithelium in vivo, in which a few unique genes were highly expressed when compared with both skin and oral mucosa epithelium in vivo using clustering analysis. However, we could not detect a single marker specific to vermilion epithelium supported by the gene expression profile of a Japanese macaque. Instead, the pair of keratin 10 and small proline-rich protein 3 resulted in a potential marker of vermilion epithelium in the human lip (female, 53-year-old) via a double-immunostaining technique. Nonetheless, our result may provide further clues leading to other potential markers of the vermilion epithelium. Full article

Translational research often requires the testing of experimental therapies in primates, but research in non-human primates is now stringently controlled by law around the world. Tissues fixed in formaldehyde without glutaraldehyde have been thought to be inappropriate for use in electron microscopic analysis, particularly those of the brain. Here we report the immunoelectron microscopic characterization of arginine vasopressin (AVP)-producing neurons in macaque hypothalamo-pituitary axis tissues fixed by perfusion with 4% formaldehyde and stored at −25 °C for several years (4–6 years). The size difference of dense-cored vesicles between magnocellular and parvocellular AVP neurons was detectable in their cell bodies and perivascular nerve endings located, respectively, in the posterior pituitary and median eminence. Furthermore, glutamate and the vesicular glutamate transporter 2 could be colocalized with AVP in perivascular nerve endings of both the posterior pituitary and the external layer of the median eminence, suggesting that both magnocellular and parvocellular AVP neurons are glutamatergic in primates. Both ultrastructure and immunoreactivity can therefore be sufficiently preserved in macaque brain tissues stored long-term, initially for light microscopy. Taken together, these results suggest that this methodology could be applied to the human post-mortem brain and be very useful in translational research. Full article

Cooperation occurs amongst individuals embedded in a social environment. Consequently, cooperative interactions involve a variety of persistent social influences such as the dynamics of partner choice and reward division. To test for the effects of such dynamics, we conducted cooperation experiments in a captive population of Japanese macaques (Macaca fuscata, N = 164) using a modified version of the loose-string paradigm in an open-experiment design. We show that in addition to becoming more proficient cooperators over the course of the experiments, some of the macaques showed sensitivity to the presence of potential partners and adjusted their behavior accordingly. Furthermore, following an unequal reward division, individuals receiving a lesser reward were more likely to display aggressive and stress-related behaviors. Our experiments demonstrate that Japanese macaques have some understanding of the contingencies involved in cooperation as well as a sensitivity to the subsequent reward division suggestive of an aversion to inequity. Full article

Papillomaviruses (PVs) are a diverse group of host species-specific DNA viruses, etiologically linked with various benign and malignant neoplasms of cutaneous and mucosal epithelia. Here, we describe the detection and characterization of the first two PVs naturally infecting Japanese macaques (Macaca fuscata), including the determination of their etiological association(s) with the development of original neoplasms. The molecular and phylogenetic analyses were performed on complete genome sequences of Macaca fuscata PV types 1 (MfuPV1) and 2 (MfuPV2), which were completely sequenced in samples of a malignant oral tumor and benign anogenital neoplasm of Japanese macaques, respectively. Subsequently, two type-specific quantitative real-time PCRs were developed to estimate viral loads of MfuPV1 and MfuPV2 and to evaluate their etiological roles. The in silico molecular analyses revealed that both viral genomes encode characteristic PV proteins with conserved functional domains and have a non-coding genomic region with regulatory sequences to regulate and complete the viral life cycle. However, additional experimental evidence is needed to finally confirm the presence and biological functionality of the molecular features of both novel PVs. While MfuPV1, together with PVs identified in other macaques, is classified into the Alphapapillomavirus (Alpha-PV) species 12, MfuPV2 is most likely a representative of the novel viral species within the Alpha-PV genus. Their relatively high viral loads suggest that both PVs are etiologically linked with the development of the original neoplasms. Full article

The Stroop effect describes interference in cognitive processing due to competing cognitive demands. Presenting emotionally laden stimuli creates similar Stroop-like effects that result from participants’ attention being drawn to distractor stimuli. Here, we adapted the methods of a pictorial Stroop study for use with chimpanzees (N = 6), gorillas (N = 7), and Japanese macaques (N = 6). We tested all subjects via touchscreens following the same protocol. Ten of the 19 subjects passed pre-test training. Subjects who reached criterion were then tested on a standard color-interference Stroop test, which revealed differential accuracy in the primates’ responses across conditions. Next, to test for an emotional Stroop effect, we presented subjects with photographs that were either positively valenced (a preferred food) or negatively valenced (snakes). In the emotional Stroop task, as predicted, the primates were less accurate in trials which presented emotionally laden stimuli as compared to control trials, but there were differences in the apes’ and monkeys’ response patterns. Furthermore, for both Stroop tests, while we found that subjects’ accuracy rates were reduced by test stimuli, in contrast to previous research, we found no difference across trial types in the subjects’ response latencies across conditions. Full article

Whipworms are parasitic intestinal nematodes infecting mammals, and traditionally humans and other primates that have so far been considered infected by Trichuris trichiura. Recent molecular studies report a more complex scenario suggesting the presence of a species complex with several Trichuris taxa specifically infecting only one primate species as well as taxa able to infect a range of primate species. The systematics of the group is important for taxonomic inference, to estimate the relative zoonotic potential, and for conservation purposes. In fact, captive animals living in zoological gardens are usually infected by persistent monoxenous intestinal parasites. Here, two Japanese macaques living in the Bioparco Zoological Garden of Rome were found infected by Trichuris sp. Nematodes were characterized at the molecular level using nuclear (btub and 18S) and mitochondrial (16S and cytb) markers and then compared to Trichuris collected previously in the same location, and to other Trichuris infecting primates. Evidences from mitochondrial and nuclear markers allowed for the identification of Trichuris sp. specific to Macaca fuscata. Results obtained here also described a uniform taxonomic unit of Trichuris, separated but closely related to Trichuris trichiura, thus, emphasizing its zoonotic potential for workers and visitors. Full article

The effect that visitors have on the behavior and welfare of animals is a widely-studied topic in zoo animal welfare. Typically, these studies focus on how the presence or activity levels of visitors affect animals. However, for many species, and particularly primates, social factors, such as social rank, can also have a large impact on behavior. Here, we considered the influence of both the role of visitors (crowd size and activity levels) and rank on the occurrence of visitor-directed aggression by zoo-housed Japanese macaques (Macaca fuscata, N = 12). We conducted 52 weeks of observation (443.8 h) of macaques living in a large outdoor habitat and recorded 1574 events of visitor-directed behavior, 94.2% of which was characterized as aggressive. We calculated rank using the Elo-rating method. GLMM comparisons indicate that rank was a significant predictor of visitor-directed aggression, with lower-ranked individuals displaying more frequent aggression towards visitors. Additionally, visitor-directed aggression differed by crowd activity levels, but not crowd size. These results support our prediction that rank is associated with differences in visitor-directed aggression, and we interpret this pattern as lower-ranking macaques redirecting aggression toward zoo visitors as safe targets. This work emphasizes how factors emanating from the zoo environment can combine with social dynamics to influence primate response to human presence in the zoo setting. Full article