Enamel chipping in Taï Forest cercopithecids: Implications for diet reconstruction in paleoanthropological contexts.

Antemortem enamel chipping in living and fossil primates is often interpreted as evidence of hard-object feeding (i.e., 'durophagy'). Laboratory analyses of tooth fracture have modeled the theoretical diets and loading conditions that may produce such chips. Previous chipping studies of nonhuman primates tend to combine populations into species samples, despite the fact that species can vary significantly in diet across their ranges. Chipping is yet to be analyzed across population-specific species samples for which long-term dietary data are available. Here, we test the association between enamel chipping and diet in a community of cercopithecid primates inhabiting the Taï Forest, Ivory Coast. We examined fourth premolars and first molars (n = 867) from naturally deceased specimens of Cercocebus atys, Colobus polykomos, Piliocolobus badius,Procolobus verus, and three species of Cercopithecus. We found little support for a predictive relationship between enamel chipping and diet across the entire Taï monkey community. Cercocebus atys, a dedicated hard-object feeder, exhibited the highest frequencies of (1) chipped teeth and (2) chips of large size; however, the other monkey with a significant degree of granivory, Co. polykomos, exhibited the lowest chip frequency. In addition, primates with little evidence of mechanically challenging or hard-food diets-such as Cercopithecus spp., Pi. badius, and Pr. verus-evinced higher chipping frequencies than expected. The equivocal and stochastic nature of enamel chipping in the Taï monkeys suggests nondietary factors contribute significantly to chipping. A negative association between canopy preference and chipping suggests a role of exogenous particles in chip formation, whereby taxa foraging closer to the forest floor encounter more errant particulates during feeding than species foraging in higher strata. We conclude that current enamel chipping models may provide insight into the diets of fossil primates, but only in cases of extreme durophagy. Given the role of nondietary factors in chip formation, our ability to reliably reconstruct a range of diets from a gradient of chipping in fossil taxa is likely weak.

Evolution of SIVsm in humanized mice towards HIV-2.

Through the accumulation of adaptive mutations, HIV-2 originated from SIVsm. To identify these evolutionary changes, a humanized mouse model recapitulated the process that likely enabled this cross-species transmission event. Various adaptive mutations arose, as well as increased virulence and CD4+ T-cell decline as the virus was passaged in humanized mice.

Helicobacter Species Identified in Captive Sooty Mangabeys (Cercocebus atys) with Metastatic Gastric Adenocarcinoma.

BACKGROUND: Of all human cancers, gastric carcinoma is the one of the leading causes of death. Helicobacter pylori is considered a major etiologic agent of this disease. Spontaneously occurring gastric carcinoma is a rare diagnosis in nonhuman primates. A 2011 case report documented a high incidence of gastric adenocarcinoma in a closed colony of captive sooty mangabeys (Cercebus atys). However, H. pylori infection was not detected in these animals. MATERIALS AND METHODS: In this study, using archived formalin-fixed, paraffin-embedded stomach sections of these animals alternative methodologies were used to identify H. pylori and other non-H. pylori Helicobacter species. In addition, two additional cases of sooty mangabeys with metastatic gastric carcinoma are characterized. RESULTS: Using fluorescent in situ hybridization, we identified gastric H. suis in 75% of archived and new gastric carcinoma cases. In the two newly reported cases, H. suis and a novel Helicobacter species were detected via PCR and sequence analysis of the 16S rRNA gene. H. pylori was not identified in any of the gastric carcinoma cases via FISH and/or PCR and sequence analysis of Helicobacter spp. in DNA from of available tissues. CONCLUSIONS: This report is the first to characterize Helicobacter species infection in spontaneous gastric carcinoma with metastatic potential in nonhuman primates.

Molecular phylogenetic analysis of the Papionina using concatenation and species tree methods.

The Papionina is a geographically widespread subtribe of African cercopithecid monkeys whose evolutionary history is of particular interest to anthropologists. The phylogenetic relationships among arboreal mangabeys (Lophocebus), baboons (Papio), and geladas (Theropithecus) remain unresolved. Molecular phylogenetic analyses have revealed marked gene tree incongruence for these taxa, and several recent concatenated phylogenetic analyses of multilocus datasets have supported different phylogenetic hypotheses. To address this issue, we investigated the phylogeny of the Lophocebus + Papio + Theropithecus group using concatenation methods, as well as alternative methods that incorporate gene tree heterogeneity to estimate a 'species tree.' Our compiled DNA sequence dataset was ∼56 kb pairs long and included 57 independent partitions. All analyses of concatenated alignments strongly supported a Lophocebus + Papio clade and a basal position for Theropithecus. The Bayesian concordance analysis supported the same phylogeny. A coalescent-based Bayesian method resulted in a very poorly resolved species tree. The topological agreement between concatenation and the Bayesian concordance analysis offers considerable support for a Lophocebus + Papio clade as the dominant relationship across the genome. However, the results of the Bayesian concordance analysis indicate that almost half the genome has an alternative history. As such, our results offer a well-supported phylogenetic hypothesis for the Papio/Lophocebus/Theropithecus trichotomy, while at the same time providing evidence for a complex evolutionary history that likely includes hybridization among lineages.

SIV infection in sooty mangabeys does not impact survival but changes the relative frequency of the main cause of death.

Sooty mangabeys (SMs) are natural hosts of simian immunodeficiency virus (SIV) and do not progress to AIDS despite high viral replication. The main factors involved in the benign nature of this infection are (i) low level of immune activation, (ii) relative preservation of specific CD4+ T-cell subsets from direct virus infection, and (iii) absence of microbial translocation from the gut to the systemic circulation. To determine the impact of SIV infection on underlying cause of death, we retrospectively analyzed data from 307 SMs (219 SIV infected and 88 uninfected) housed at the Emory Primate Center that have died between 1986 and 2022. Interestingly, we found that SIV-infected SMs live ~4 years longer than SIV-uninfected SMs, although this result is hard to interpret due to differences in how animals were housed and assigned to specific experimental studies. While the causes of death were not different between SIV-infected and uninfected SMs that died before age 15 (i.e., adult), we found significant differences in the relative frequency of specific causes of death in the elderly population (≥15 years old). Specifically, we observed that SIV-infected SMs were more likely to die from infections but less likely to die from cardiovascular disease (and diabetes in female animals) as compared to uninfected SMs. While confirming the non-pathogenic nature of SIV infection in SMs, these data reveal, for the first time, a qualitative impact of SIV infection on the host physiology that induces a significant change in the mortality pattern in these natural SIV hosts. IMPORTANCE: In this study, we demonstrate, for the first time, that the natural, non-pathogenic SIV infection of the African monkey SM has a clinical impact which is revealed in terms of main causes of mortality, which are significantly different in the infected animals as compared to the uninfected ones. Indeed, SIV-infected SMs are at higher risk of dying of infectious diseases but appear to be somewhat protected from cardiovascular causes of death. The identification of a specific pattern of mortality associated with the infection suggests that the host-pathogen interaction between SIV and the SM immune system, while non-pathogenic in nature, has a detectable impact on the overall health status of the animals.

Jaw-Muscle Fiber Architecture and Leverage in the Hard-Object Feeding Sooty Mangabey are not Structured to Facilitate Relatively Large Bite Forces Compared to Other Papionins.

Numerous studies have sought to link craniofacial morphology with behavioral ecology in primates. Extant hard-object feeders have been of particular interest because of their potential to inform our understanding about the diets of early fossil hominins. Sooty mangabeys (Cercocebus atys) are hard-object feeders that frequently generate what have been described as audibly powerful bites at wide jaw gapes to process materially stiff and hard seeds. We address the hypothesis that sooty mangabeys have features of the masticatory apparatus that facilitate this feeding behavior by comparing fiber architecture and leverage of the masseter and temporalis muscles between sooty mangabeys and three papionin primates that do not specialize on hard objects. Contrary to predictions, sooty mangabeys do not have relatively larger muscle physiologic cross-sectional areas or weights compared to other papionins, nor do they consistently display improved leverage. In this regard, sooty mangabeys differ in their morphology from other hard-object feeders such as tufted capuchins. However, males of all four papionin species converge on a shared pattern of relatively longer anterior superficial masseter fibers compared with female conspecifics, suggesting that males are likely prioritizing muscle stretch to improve gape performance as part of a behavioral repertoire that includes agonistic social interactions and intense male-male competition. These findings strengthen support for the hypothesis that gape display behaviors can exert a strong selective influence throughout the musculoskeletal masticatory apparatus. Results also raise questions about the morphological suitability of extant cercopithecines as models for interpreting feeding behavior and diet in fossil hominins with limited jaw gape capacity. Anat Rec, 301:325-342, 2018. © 2018 Wiley Periodicals, Inc.

Influence of availability of perches on the behavioral well-being of captive, group-living mangabeys.

Environmental enrichment is expected to increase the well-being of animals. Changes in well-being can be measured by variations in behavioral patterns. This study reports on behavioral changes induced, in arboreal monkeys, by progressively increasing the number of perches, from none to five, in an "experimental cage." A cage equipped with five perches was used as the control cage. The behaviors of a group of seven gray-cheeked mangabeys in the control cage and in the "experimental" cage were compared. A total deprivation of perches yielded an increase in aggressive behaviors and locomotion, and a decrease in cohesiveness. Placing perches progressively in the experimental cage restored the level of all the variables to levels found in the control cage. This restoration to control levels actually occurred only when the number of perches in the experimental cage was close or equal to that in the control cage. Therefore perches constitute a necessary feature of an adequate environment for mangabeys. We suggest that this restoration is a consequence of providing appropriate structure of the utilizable space for the monkeys. This structure might increase the control and the predictability that monkeys should have over social events. © 1996 Wiley-Liss, Inc.

Information content of sexual swellings and fecal steroids in sooty mangabeys (Cercocebus torquatus atys).

The accuracy and precision of sexual swellings and fecal steroids as measures of ovarian function and the periovulatory period were compared in 4 sexually mature, individually housed, sooty mangabey females. Fecal samples were collected daily over a 10-week period during the normal breeding season. Serum was collected 3×/week, daily during peak swelling, and sex skin was rated 5×/week on a 0-5 relative scale. Both fecal estradiol (fE2) and progesterone (fP4) were significantly correlated with serum values in composite E2-aligned profiles and within the cycles of individual females with average correlations of rs = 0.6. Follicular phase means for fE2 and luteal phase means for fP4 were significantly correlated with the serum means across cycles, suggesting that fecal concentrations could be used to accurately evaluate cycle phases within and across females. In contrast, the timing of peak swelling relative to the periovulatory period varied considerably across the cycles of individual females. Although maximum tumescence appears to bracket the periovulatory period, individual differences in the duration of peak swelling and the timing of its onset and end tend to obscure the exact time of ovulation in relation to maximal tumescence. These data illustrate the utility of fecal steroid analysis as a tool for further evaluation of the signal value of sexual skin and its role in mating interactions. © 1996 Wiley-Liss, Inc.

Attacks on neonates by a male mangabey (Cercocebus atys).

Aggressive behavior by an adult male toward selected infants and their mothers was observed during a long-term study of reproduction in a captive social group of sooty mangabeys (Cercocebus atys). The highest-ranking adult male in this group was observed to attack and bite three neonates out of a total of 13 infants born in 1982. All three attacks were directed attacks in which infants were grabbed from their mothers and bitten in the head. The first infant was fatally injured; the other two probably would have sustained fatal wounds had the male's canines not been blunted beforehand and had observers not intervened. The attacks were preceded by a pattern in which the male persistently stalked or chased the mother-infant pairs, a behavior first observed in the hours immediately following parturition. Unlike attacks in wild baboon groups following male immigration, these attacks on infants occurred in a stable social group in which the male attacker had been a lifelong resident. This male, however, had gained alpha rank only 3 months before attacking the first infant. These attacks, in the context of other evidence of aggression and wounding, are discussed relative to current models of infanticide in primates.

Infant carrying by adult male mangabeys (Cercocebus atys).

Sixty-five interactions where an adult male carried an infant in the proximity of a second male were observed during a 19-mo period in a captive sooty mangabey (Cercocebus atys) social group. The behavior was distributed nonrandomly in both the adult male and infant classes. In all but three of the interactions, the recently deposed alpha male carried an infant in the presence of the newly ascendant dominant male. In the first phase of the study, infants that were carried included the entire unweaned infant cohort (n = 5) born before the rank reversal. The rate of carrying in this class declined as a function of increasing infant age and time since the rank reversal. Infant carrying was not observed in the context of fighting, which was rare, and intermale aggression never preceded the behavior. However, in 40% of the cases, carrying occurred after an infant had been threatened by the dominant male. These results suggest that infant carrying served to protect the infant from aggression rather than to exploit the infant as an agonistic buffer. The data did not unequivocally support the postulate that carrying may be a form of paternal care since paternity could not be assessed. The similar structural and contextual patterns of infant carrying in this species suggest a common origin for triadic male-infant interactions in mangabeys and baboons.

Ménétrier's disease-like hypertrophic gastritis in two red-capped mangabeys (Cercocebus torquatus).

Chronic lymphoplasmacytic gastritis in two red-capped mangabeys (Cercocebus torquatus) at a zoological facility progressed to severe hypertrophic gastropathy similar to Ménétrier's disease that affects humans. Clinical signs included emesis, diarrhea, hunched posture consistent with abdominal pain, anemia, and hypoproteinemia. Large gastric masses were present and in one case created a gastric outflow obstruction. Both cases were positive for simian immunodeficiency virus and Helicobacter spp. were variably isolated, although the association with the hypertrophic gastropathy is unclear. Medical treatment had varying success and included sucralfate, H2 receptor antagonists, proton pump inhibitors, diet manipulations, and antibiotic therapies targeting Helicobacter spp. Surgical resection of a large portion of the stomach resulted in some palliative improvement in one case. Overall, this disease presented many challenges regarding identification, confirmation of diagnosis, and clinical management. Both aggressive medical and surgical treatments were unrewarding for long-term management of hypertrophic gastropathy in this pair of red-capped mangabeys and resulted in a poor prognosis in these cases.