Showing papers on "Primate published in 2006"

Evolution of increased glia-neuron ratios in the human frontal cortex.

Abstract: Evidence from comparative studies of gene expression and evolution suggest that human neocortical neurons may be characterized by unusually high levels of energy metabolism. The current study examined whether there is a disproportionate increase in glial cell density in the human frontal cortex in comparison with other anthropoid primate species (New World monkeys, Old World monkeys, and hominoids) to support greater metabolic demands. Among 18 species of anthropoids, humans displayed the greatest departure from allometric scaling expectations for the density of glia relative to neurons in layer II/III of dorsolateral prefrontal cortex (area 9L). However, the human glia-neuron ratio in this prefrontal region did not differ significantly from allometric predictions based on brain size. Further analyses of glia-neuron ratios across frontal areas 4, 9L, 32, and 44 in a sample of humans, chimpanzees, and macaque monkeys showed that regions involved in specialized human cognitive functions, such as "theory of mind" (area 32) and language (area 44) have not evolved differentially higher requirements for metabolic support. Taken together, these findings suggest that greater metabolic consumption of human neocortical neurons relates to the energetic costs of maintaining expansive dendritic arbors and long-range projecting axons in the context of an enlarged brain.

Risk, resilience, and gene x environment interactions in rhesus monkeys.

Abstract: Recent research with both humans and rhesus monkeys has provided compelling evidence of gene-environment (GxE) interactions throughout development. For example, a specific polymorphism ("short" allele) in the promoter region of the serotonin transporter (5-HTT) gene is associated with deficits in neurobehavioral functioning during infancy and in poor control of aggression and low serotonin metabolism throughout juvenile and adolescent development in monkeys who were reared with peers but not in monkeys who were reared with their mothers and peers during infancy. In contrast, monkeys possessing the "long" allele of the 5-HTT gene exhibit normal neurobehavioral functioning, control of aggression, and serotonin metabolism regardless of their early social rearing history. One interpretation of these GxE interaction data is that the "long" 5-HTT allele somehow confers resiliency to adverse early attachment relationships on those individuals who carry it ("good genes"). An alternative interpretation of the same data is that secure attachment relationships somehow confer resiliency to individuals who carry alleles that may otherwise increase their risk for adverse developmental outcomes ("maternal buffering"). These two interpretations are not mutually exclusive, but the difference in their respective implications for developing prevention and even intervention strategies is considerable. Moreover, the allelic variation seen in certain genes in rhesus monkeys and humans but apparently not in other primate species may actually contribute to their remarkable adaptability and resilience at the species level.

New Perspectives in the Study of Mesoamerican Primates: Distribution, Ecology, Behavior, and Conservation

Abstract: Movements of a wild night monkey (Aotus trivirgatus)- Overview of the Mesoamerican Primate Fauna, Primate Studies, and Conservation Concerns- Taxonomy and Biogeography- Introduction: Taxonomy and Biogeography- Taxonomy and Distributions of Mesoamerican Primates- The Biogeographic History of Mesoamerican Primates- Population Responses to Disturbance- Introduction: Population Responses to Disturbance- Demographic Features of Alouatta pigra Populations in Extensive and Fragmented Forests- Population Structure of Black Howlers (Alouatta pigra) in Southern Belize and Responses to Hurricane Iris- The Effects of Forest Fragment Age, Isolation, Size, Habitat Type, and Water Availability on Monkey Density in a Tropical Dry Forest- Forest Fragmentation and Its Effects on the Feeding Ecology of Black Howlers (Alouatta pigra) from the Calakmul Area in Mexico- Intestinal Parasitic Infections in Alouatta Pigra in Tropical Rainforest in Lacandona, Chiapas, Mexico: Implications for Behavioral Ecology and Conservation- Behavior and Ecology- Introduction: Behavior and Ecology- Average Body Weight for Mantled Howling Monkeys (Alouatta palliata): An Assessment of Average Values and Variability- An Exploratory Analysis of Developmental Plasticity in Costa Rican Mantled Howler Monkeys (Alouatta palliata palliata)- Travel Patterns and Spatial Mapping in Nicaraguan Mantled Howler Monkeys (Alouatta palliata)- Use of Landmark Cues to Locate Feeding Sites in Wild Capuchin Monkeys (Cebus capucinus): An Experimental Field Study- Leap, Bridge, or Ride? Ontogenetic Influences on Positional Behavior in Cebus and Alouatta- Food Choice by Juvenile Capuchin Monkeys (Cebus capucinus) in a Tropical Dry Forest- Why Be Alpha Male? Dominance and Reproductive Success in Wild White-Faced Capuchins (Cebus capucinus)- Post-conceptive Mating in White-Faced Capuchins, Cebus capucinus: Hormonal and Sociosexual Patterns of Cycling, Noncycling, and Pregnant Females- Conservation and Management Policies- Introduction: Conservation and Management Policies- Growth of a Reintroduced Spider Monkey (Ateles geoffroyi) Population on Barro Colorado Island, Panama- Primates in Agroecosystems: Conservation Value of Some Agricultural Practices in Mesoamerican Landscapes- Primate Populations in the Protected Forests of Maya Archaeological Sites in Southern Mexico and Guatemala- Mapping Primate Populations in the Yucatan Peninsula, Mexico: A First Assessment- A Metapopulation Approach to Conserving the Howler Monkey in a Highly Fragmented Landscape in Los Tuxtlas, Mexico- Quantifying Fragmentation of Black Howler (Alouatta pigra) Habitat after Hurricane Iris (2001), Southern Belize- Synopsis and Perspectives- New Perspectives in the Study of Mesoamerican Primates: Concluding Comments and Conservation Priorities

Taxonomy and Distributions of Mesoamerican Primates

Abstract: Geoffroy’s tamarin, a squirrel monkey, a night monkey, the white-throated capuchin, two or three species of howlingmonkey, and one or two spider monkeys comprise the primate fauna ofMiddle America, historically throughout the subtropical and tropical forests from about 24oN in Tamaulipas, Mexico, extending south along the coast of the Gulf of Mexico, through Central America to the border of Colombia and Panama. This is the simple description, and hides a remarkable, and still poorly understood, diversity of 7–9 species and up to 22 taxa,

Function, ontogeny and canalization of shape variance in the primate scapula.

Abstract: Primates have shoulders adapted to a wide range of locomotor functions from terrestrial pronograde quadrupedalism to highly arboreal suspensory behaviours. The shape of the scapula tightly follows these functional differences. Previous analyses of primate postcrania, including the scapula, indicate that quadrupedal monkeys are less variable than non-quadrupeds. It was previously suggested that this difference was due to a relationship between the strength of stabilizing selection and the functional demands of the upper limb. Here it is shown that intraspecific scapular shape variance is highly correlated with the degree of committed quadrupedalism. Primates that engage in frequent suspensory behaviours (e.g. apes and ateline monkeys) average twice the amount of shape variance as quadrupeds (e.g. Old World monkeys and Saimiri). Because this difference in intraspecific shape variance is apparent in infants and does not increase or decrease appreciably over ontogeny, it is not likely that differences in postnatal growth, neuromuscular control or environmental factors such as habitat structure/composition are the primary contributors to differences in adult shape variance. Instead variance in embryonic factors that affect the shape/size of the scapula or epigenetic factors associated with muscle attachments are more likely candidates. In particular, the heterogeneous functional demands of the non-quadrupedal shoulder probably reduce the stringency of stabilizing selection, resulting in the persistence into adulthood of increased amounts of embryonically generated scapular shape variance.

CYP2C76, a novel cytochrome P450 in cynomolgus monkey, is a major CYP2C in liver, metabolizing tolbutamide and testosterone.

Abstract: Monkeys are widely used as a primate model to study drug metabolism because they generally show a metabolic pattern similar to humans. However, the paucity of information on cytochrome P450 (P450) genes has hampered a deep understanding of drug metabolism in the monkey. In this study, we report identification of the CYP2C76 cDNA newly identified in cynomolgus monkey and characterization of this CYP2C along with cynomolgus CYP2C20, CYP2C43, and CYP2C75. The CYP2C76 cDNA contains the open reading frame encoding a protein of 489 amino acids that are only approximately 80% identical to any human or monkey P450 cDNAs. Gene and protein expression of CYP2C76 was confirmed in the liver of cynomolgus and rhesus monkeys but not in humans or the great apes. Moreover, CYP2C76 is located at the end of the CYP2C gene cluster in the monkey genome, the region of which corresponds to the intergenic region adjacent to the CYP2C cluster in the human genome, strongly indicating that this gene does not have the ortholog in humans. Among the four CYP2C genes expressing predominantly in the liver, the expression level of CYP2C76 was the greatest, suggesting that CYP2C76 is a major CYP2C in the monkey liver. Assays for the capacity of CYP2C76 to metabolize drugs using several substrates typical for human CYP2Cs revealed that CYP2C76 showed unique metabolic activity. These results suggest that CYP2C76 contributes to overall drug-metabolizing activity in the monkey liver and might account for species difference occasionally seen in drug metabolism between monkeys and humans.

Nursery Rearing of Nonhuman Primates in the 21st Century

Abstract: Preface. -Introduction to Section 1. -The Effects of Rearing Experiences: The Early Years. -The Changing Role of Hand-Rearing in Zoo-Based Primate Breeding Programs. -Animal Welfare Regulations and Nursery Rearing. -Data Management for the Nonhuman Primate Nursery. -Very Early Rearing Experience: Rationale and Methodologies for Studying Prenatal Development in Nonhuman Primates. -Introduction to Section 2. -The Effect of Hand-Rearing on the Sexual and Maternal Competence of Three Species of Lemurs: Varecia variegate, Varecia rubra, and Eulemur macaco. -Nursery-Reared Prosimian Primates. -Hand-Rearing of Infant Common Marmosets (Callithrix jacchus). -Introduction to Section 3. -Immunological Consequences of Nursery Rearing. -Special Challenges of Rearing Infant Macaques Infected with Lentivirus (SIV, HIV, SHIV). -Nursery Rearing and Biobehavioral Organization. -Introduction to Section 3. -Neurobehavioral Assessment of Nonhuman Primate Neonates. -Is it Nutrients or Nurturing?: Comparison of the Growth and Development of Mother-Reared and Laboratory-Reared Macaque Infants. -Baboon Nursery Rearing Practices and Comparisons between Nursery- and Mother-Reared Individuals. -Early Rearing Conditions and Captive Chimpanzee Behavior: Some Surprising Findings. -Effects of Early Rearing History on Growth and Behavioral Development in Captive Chimpanzees (Pan troglodytes). -Introduction to Section 4. -Squirrel Monkeys as an Example of Primate Nursery Medicine. -Nursery Care of At-Risk Nonhuman Primates. -A Quick and Effective Method for Establishing Self-Feeding in Stump-Tailed Macaques (Macaca arctoides). -Saliva as a Medium for Assessing Cortisol and other Compounds in Nonhuman Primates: Collection, Assay, and Examples. -The SPIT Method: For Simultaneous and Unobtrusive Collection of Salivary Cortisol from Individually Housed Infant Monkeys. -Actimetry Measurement of Behavioral Regulation and Sleep Cycles in InfantRhesus Macaques (Macaca mulatta). -Noninvasive Neuroimaging Techniques for the Study of Primate Brain Development. -Tethering with Maternal and Fetal Catheterization: Technology and Theory for Studying Pre- to Postnatal Continuities. -Introduction to Section 5. -Hematology and Serum Chemistry in Young Captive Chimpanzees (Pan troglodytes). -Hematology and Serum Chemistry Reference Values for Rhesus Macaque. Hematology and Serum Chemistry Reference Values for Pigtailed Macaque (Macaca nemestrina) Infants. -Hematology and Serum Chemistry Reference Values for Mother-Reared Squirrel Monkey (Saimiri boliviensis boliviensis) Infants. -Index.

Human-Nonhuman Primate Interconnections and Their Relevance to Anthropology

Abstract: The human-nonhuman primate interface is a core component in conservation and an emerging area of discourse across anthropology. There is a growing recognition of the relevance of long-term sympatry between human and nonhuman primates. Until recently these relationships received limited attention in the anthropological literature and in the primatological construction of models for the behavior and evolution of primate societies. Most socioecological investigations into primate groups and human populations do not incorporate their interactions (beyond predation or crop raiding), potential pathogen sharing, or the role of the anthropogenically impacted environment. Current relationships between humans and nonhuman primates are generally assumed to be rooted in conflict over land use and relatively recent, and thus have limited evolutionary and long term ecological impact. To date, too few studies have attempted to incorporate specific aspects of human cultural conceptualizations of nature and nonhuman primates into explanations/examination of either human or nonhuman primate behavioral and ecological patterns. Ongoing research projects and a growing number of publications demonstrate that long-term sympatry between human and nonhuman primates results in a complex web of behavioral, ecological, epidemiological, and economic relationships, suggesting a need for increased attention by anthropologists to this topic. This essay introduces a set of articles in this issue of Ecological and Environmental Anthropology that illustrate theoretical and practical considerations suggesting the need for increased focus of the anthropological gaze towards the human-nonhuman primate interface. Human-nonhuman Primate Interactions: the Ethnoprimatological Approach Because of the biological, phylogenetic, and behavioral overlaps between humans and nonhuman primates, relationships between the two groups have a special significance (Fuentes and Wolfe 2002). No other organisms on the planet share as much structurally and behaviorally with humans. Humans, along with other primates, exhibit a series of primate wide trends such as grasping hands, relatively large brains, an emphasis on visual signaling, extended infant dependency, and behaviorally dynamic social complexity, for example. The existence of these primate wide trends in both morphology and behavior suggest the possibility that interconnections between humans and other primate species may differ from those between humans and other mammals. These human-nonhuman primate similarities increase both the likelihood of cultural association/inclusion of other primates by humans, and certain primates’ potential to co-exist with humans. As is evident from the rapid and dramatic reduction in numbers and range, especially the great apes and the monkeys and lemurs tied to large tracts of forest cover, some species of primates do not do well when they encounter anthropogenic challenges. However, in many instances other species, members of the monkey genera Macaca (the macaques), Papio (the baboons), and Chlorocebus (the vervets) for example, do quite well around humans.

How Capuchin Monkeys (Cebus apella) Quantify Objects and Substances

Abstract: Humans and nonhuman animals appear to share a capacity for nonverbal quantity representations. But what are the limits of these abilities? Results of previous research with human infants suggest that the ontological status of an entity as an object or a substance affects infants' ability to quantify it. We ask whether the same is true for another primate species-the New World monkey Cebus apella. We tested capuchin monkeys' ability to select the greater of two quantities of either discrete objects or a nonsolid substance. Participants performed above chance with both objects (Experiment 1) and substances (Experiment 2); in both cases, the observed performance was ratio dependent. This finding suggests that capuchins quantify objects and substances similarly and do so via analog magnitude representations.

Diet and Travel Costs for Spider Monkeys in a Nonseasonal, Hyperdiverse Environment

Abstract: I studied the effects of a nonseasonal environment with a high diversity of plant species in a community of white-bellied spider monkeys (Ateles belzebuth belzebuth) in the Yasuni National Park, Ecuador. During 10 2-wk follows of focal individuals across 1 yr, I collected 1268 h of observation data on ranging and foraging. The environment had strong effects on both the foraging and ranging behavior of the monkeys. Yasuni spider monkeys are similar to spider monkeys in more seasonal environments in that ripe-fruit consumption dominates the diet. However, Yasuni spider monkeys exhibit an extremely diverse diet that parallels the variety of foods available to them, consuming more than 238 species of fruits. The impressive dietary variety increased even more with increased observation time, as I had not previously observed in the spider monkeys’ diet 40% of the fruit species the subjects consumed during the final follow. Ripe fruits remain the most important item in the diet year-round, supplemented with decayed wood or leaf flush. Local rarity of plant species means that fruiting patches are an average of 420 m apart, and mean patch residence times are short, only 8.1 min. Visits to an average of 11.5 feeding patches/d lead to a mean daily path length of 3311 m, longer than reported for any other Ateles species, and long compared to most other primate species. The long daily paths of Yasuni spider monkeys reflect travel costs resulting from foraging in a hyperdiverse nonseasonal environment.

Vervet monkeys and humans show brain asymmetries for processing conspecific vocalizations, but with opposite patterns of laterality

Abstract: A robust finding in the human neurosciences is the observation of a left hemisphere specialization for processing spoken language. Previous studies suggest that this auditory specialization and brain asymmetry derive from a primate ancestor. Most of these studies focus on the genus Macaca and all demonstrate a left hemisphere bias. Due to the narrow taxonomic scope, however, we lack a sense of the distribution of this asymmetry among primates. Further, although the left hemisphere bias appears mediated by conspecific calls, other possibilities exist including familiarity, emotional relevance and more general acoustic properties of the signal. To broaden the taxonomic scope and test the specificity of the apparent hemisphere bias, we conducted an experiment on vervets (Cercopithecus aethiops)-a different genus of old world monkeys and implemented the relevant acoustic controls. Using the same head orienting procedure tested with macaques, results show a strong left ear/right hemisphere bias for conspecific vocalizations (both familiar and unfamiliar), but no asymmetry for other primate vocalizations or non-biological sounds. These results suggest that although auditory asymmetries for processing species-specific vocalizations are a common feature of the primate brain, the direction of this asymmetry may be relatively plastic. This finding raises significant questions for how ontogenetic and evolutionary forces have impacted on primate brain evolution.

Electroencephalographic and convulsant effects of the delta opioid agonist SNC80 in rhesus monkeys

Abstract: Non-peptidic delta opioid receptor agonists are being evaluated for a wide range of clinical applications; however, the clinical utility of piperazinyl benzamide delta agonists such as SNC80 may be limited by convulsant activity. The purpose of the present study was to evaluate the electroencephalographic and convulsant activity produced by a high dose of 10 mg/kg SNC80 IM in rhesus monkeys. EEG and behavioral activity were examined in four adult male rhesus monkeys after IM administration of SNC80. Monkeys were seated in a standard primate restraint chair, and EEG activity was recorded using an array of 16 needle electrodes implanted subcutaneously in the scalp in a bipolar (scalp-to scalp) montage in a longitudinal direction, with bilateral frontal, central, temporal, and occipital leads. Behavior was recorded using video monitoring equipment. Initially, all monkeys were tested with 10 mg/kg SNC80, which is a relatively high dose 3–10 fold greater than doses necessary to produce a variety of other behavioral effects. Behavioral convulsions and EEG seizures were observed in one of the four monkeys. In this monkey, neither behavioral convulsions nor EEG seizures were observed when a lower dose of 3.2 mg/kg was administered nine weeks later or when the same dose of 10 mg/kg SNC80 was administered one year later. These results suggest that IM administration of SNC80 is less potent in producing convulsant effects than in producing other, potentially useful behavioral effects (e.g. antinociception) in rhesus monkeys.

Cutting corners: the dynamics of turning behaviors in two primate species.

Abstract: SUMMARY In an attempt to characterize more fully the variation in substrate reaction forces in the locomotor repertoire of primates, we recorded the forces involved in directional changes for two species. These are the first records of turning forces for vertebrate quadrupeds, much less primates. Three ring-tailed lemurs and two patas monkeys performed turns of approximately 30° as they crossed a force platform. The ring-tailed lemurs also turned on a horizontal branch-like support with a segment attached to the force transducer. Mediolateral forces of up to 40% body weight were recorded. These are considerably higher than during linear locomotion. Pivot limbs in ground turns and turns on the branch differed in the lemurs, suggesting that substrate influences turning strategies. Limbs encountered both medial and lateral reaction forces, and as a result, they may be exposed to variable bending regimes in the frontal plane. The stereotypy in bending regimes suggested by in vivo bone strain studies, therefore, may characterize linear locomotion only. The lemurs showed hindlimb dominance in turns, both in terms of frequency used as well as force magnitude (hindlimb steering). Hindlimb dominance in weight support characterizes both species (and primates in general), but it is more pronounced in the lemurs. In the patas monkeys, forces were more evenly distributed among the two pairs of limbs. The mediolateral turning forces therefore seem to track the amount of weight to be shifted sideways. Overall variance in mediolateral forces was greater in the arboreal and versatile lemurs than in the terrestrial and cursorial patas monkeys.

Duplication and Divergence of 2 Distinct Pancreatic Ribonuclease Genes in Leaf-Eating African and Asian Colobine Monkeys

Abstract: Unique among primates, the colobine monkeys have adapted to a predominantly leaf-eating diet by evolving a foregut that utilizes bacterial fermentation to breakdown and absorb nutrients from such a food source. It has been hypothesized that pancreatic ribonuclease (pRNase) has been recruited to perform a role as a digestive enzyme in foregut fermenters, such as artiodactyl ruminants and the colobines. We present molecular analyses of 23 pRNase gene sequences generated from 8 primate taxa, including 2 African and 2 Asian colobine species. The pRNase gene is single copy in all noncolobine primate species assayed but has duplicated more than once in both the African and Asian colobine monkeys. Phylogenetic reconstructions show that the pRNase-coding and noncoding regions are under different evolutionary constraints, with high levels of concerted evolution among gene duplicates occurring predominantly in the noncoding regions. Our data suggest that 2 functionally distinct pRNases have been selected for in the colobine monkeys, with one group adapting to the role of a digestive enzyme by evolving at an increased rate with loss of positive charge, namely arginine residues. Conclusions relating our data to general hypotheses of evolution following gene duplication are discussed.

Spatial distribution of primates in a mosaic of colonizing and old growth forest at Ngogo, Kibale National Park, Uganda

Abstract: Primate censuses were conducted in a mosaic of colonizing (two locations) and old-growth forests using line transect methods at the Ngogo study site, Kibale National Park, Uganda. Black and white colobus monkeys (Colobus guereza) were encountered more frequently in the colonizing forests than in the old growth forest, while chimpanzees (Pan troglodytes) were encountered more frequently in the old growth forest than in colonizing forests. Although not significant, results suggest that blue monkeys (Cercopithecus mitis) frequented colonizing forests more often than old growth forest. The encounter rates of mangabey (Lophocebus albigena), and redtail (Cercopithecus ascanius) groups were ambiguous with their density being higher in some colonizing forests but not others as compared to old-growth forest. No significant differences were detected for baboons (Papio anubis), L’hoest’s (Cercopithecus lhoesti), and red colobus monkeys (Piliocolobus tephroscales). The conversion of forests to farmland is one of the major problems encountered in primate conservation. This study shows that secondary forests replacing anthropogenic grasslands have the potential of supporting some primate species such as black and white colobus, redtail monkeys, and possibly blue monkeys. Therefore, such areas should not be given up but should be conserved for the benefit of primates that can survive in secondary forests; as the forests mature further, primate species that are adapted to old growth forest will colonize the area provided there is a nearby source.

Sleep quantitation in common marmoset, cotton top tamarin and squirrel monkey by non-invasive actigraphy.

Abstract: Sleep quantitation data on the Neotropical primate species, apart from the squirrel monkey, are still sparse. As such, we have quantitated sleep in the common marmosets (Callithrix jacchus), cotton top tamarins (Saguinus oedipus) and squirrel monkeys (Saimiri sciureus) reared in one primate facility simultaneously, by non-invasive actigraphy. The range in total sleep time/24h measured for male adult common marmosets, cotton top tamarins and squirrel monkeys were 713-793 min (n=4), 707-889 min (n=4) and 459-475 min (n=2) respectively. The range in sleep episode length /12h dark phase for marmosets, tamarins and squirrel monkeys were 21-52 min (n=3), 10-28 min (n=4) and 9-15 min (n=2) respectively. Since vigilance is a critical evolutionary adaptive feature of predator avoidance among Callitrichid monkeys and squirrel monkeys, the shorter ranges in sleep episode length recorded, even under captivity, in this study could be interpreted as probable indicators of such vigilance behavior during the rest phase. We hypothesize that the vigilance behavior when it exists during a primate's active phase should also prevail when it is at rest (sleep). This hypothesis deserves additional testing in female Callitrichid monkeys.

Fast and non-invasive PCR sexing of primates: apes, Old World monkeys, New World monkeys and Strepsirrhines

Abstract: Background One of the key tools for determining the social structure of wild and endangered primates is the ability to sex DNA from small amounts of non-invasive samples that are likely to include highly degraded DNA. Traditional markers for molecular sex determination of primates are developed on the basis of the human sequence and are often non-functional in distantly related primate species. Hence, it is highly desirable to develop markers that simultaneously detect Y- and X-chromosome specific sequences and also work across many species.

Expression profiles of endogenous retroviruses in Old World monkeys.

Abstract: Human endogenous retroviruses (HERVs) are a major component of the human genome and an active part of the transcriptome. Some HERVs play vital biological roles, while others potentially contribute to diseases. Many HERVs are relatively new in the primate genome, having entered or expanded after the lineages leading to the platyrrhines (New World monkeys) and catarrhines (Old World monkeys and apes) separated. Most HERVs are active in at least some tissues, though tissue specificity is common for most elements. We analyzed multiple tissues from several Old World monkeys using retroviral pol-based DNA microarrays and quantitative PCR methods to determine their ERV expression profiles. The results demonstrate that while many ERVs are active in nonhuman primates, overall the tissue expression specificity is unique to each species. Most striking is that while the majority of HERVs analyzed in this study are expressed in human brain, almost none are expressed in Old World monkey brains or are only weakly expressed.

Characterization of obesity in Japanese monkeys (Macaca fuscata) in a pedigreed colony.

Abstract: Background Japanese monkey, Macaca fuscata, is recognized as the monkey species inhabiting the northernmost area in the world, and thus likely to possess unique fat-depositing mechanisms to resist cold weather in winter. We report that obese females are present in the Wakasa group of Japanese monkey reared in an open enclosure of the Primate Research Institute, Kyoto University. Methods and Results Eight of 12 females were categorized as obese, showing percentage body fat of over 22%. The levels of serum leptin (mean ± SD, 4.9 ± 2.3 ng/ml) measured in these obese monkeys were significantly higher than those of non-obese peers of the same group (n = 4; 1.2 ± 0.5 ng/ml) and another Japanese monkey group (Takahama, n = 14; 0.8 ± 0.25 ng/ml); however, serum levels of adiponectin, insulin, glucose, hemoglobin A1c, and fructosamine did not differ between obese and non-obese monkeys. Few serum lipid parameters such as triglyceride and cholesterol showed lower levels in obese monkeys than their non-obese peers. Conclusions These results show that these obese monkeys in the Wakasa group have not developed obesity-related diseases/disorders such as diabetes. In the Wakasa group, the frequency of obese individuals was high in some maternal lineages, suggesting that genetic factors responsible for obesity may have been inherited in these lineages.

Fetal ultrasonography: biometric data from four African primate species.

Abstract: Background Nonhuman primates are raised in large numbers in research centers and zoos. Reproductive monitoring is required to improve breeding performances. Ultrasonography is a safe method to determine gestational age and to estimate the date of parturition. However only few data are available in nonhuman primates. Methods Fetal biometric data were obtained throughout pregnancy on four African primate species, namely chimpanzee, gorilla, mandrill and patas monkey. Measurements included biparietal diameter, transverse abdominal diameter, femur and humerus length, external interorbital diameter, and fetal heart rate. Curves established from these data were compared with previously published data in chimpanzees and gorillas and with those for humans and other closely related primate species. Results The curves for the different hominids were very similar, while those for mandrills more closely resembled baboons and data for patas monkeys were comparable to those for macaques. Conclusions These data, by providing a tool to evaluate precise gestational age, will be useful for centers raising these four primate species.

Molecular evolution of the HERV-E family in primates

Abstract: More than 50 copies of HERV-E family elements have been estimated to exist in the human genome. Here we examined the recent evolutionary history of the HERV-E family by a PCR approach using genomic DNA from hominoid primates and a human monochromosomal panel. From the HERV-E family, 25 and 68 env fragments, were identified and analyzed from hominoid primates and human chromosomes 1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 19, X, and Y, respectively. They showed 76.7-99.6% sequence similarity to that of HERV-E (accession no. M10976). Phylogenetic analysis of HERV-E env family distinctively divided into two groups (groups I and II) that each contained three subgroups. Divergence times of the two groups were estimated as 10.7 MYr for group I and 41.3 MYr for group II using an average evolutionary rate of 0.3% per MYr. These data are consistent with that of PCR analysis, which showed a band of the HERV-E family in the genomes of the hominoids, Old World monkeys, and New World monkeys. Therefore, the HERV-E family may have integrated into the primate genome after prosimians and New World monkeys diverged. Then they proliferated extensively in the genome of humans and great apes during primate evolution.

Endogenous retrovirus HERV-I LTR family in primates: sequences, phylogeny, and evolution

Abstract: A human endogenous retrovirus (HERV-I; RTVL-I) has been located within the first intron of a haptoglobin-related gene. Two members of the HERV-I family were identified in proximal Yq11.2 and caused AZFa microdeletions as a result of intra-chromosomal recombination events in azoospermic patients. Using PCR25 and the sequencing approach with the genomic DNAs of primates, hominoids, Old and New World monkeys, and prosimians, the HERV-I LTR elements were identified and analysed. The LTR elements were detected only in the hominoids and the Old World monkeys, indicating that the HERV-I LTR elements were inserted into the primate genome after the split of the New World monkeys in the Oligocene era, about 33 million years ago. Nineteen members of the HERV-I LTR elements from the hominoids and the Old World monkeys showed multiple insertions or deletions. They showed a 78.6-97.4% sequence similarity to that of Hu-15 (accession no. AF290422; HERV-I LTR on human Yq11.2). The evolutionary relationships within the HERV-I LTR family among hominoids and Old World monkeys showed a random cluster, indicating that HERV-I LTR elements have evolved independently in primate evolution.

Chimpanzee Learning and Transmission of Tool Use to Fish for Honey

Abstract: Since the early 1950s, Japanese primatologists have conducted research to examine culture in nonhuman animals (Hirata et al. 2001). Imanishi (1952) proposed that an important aspect of culture is learning from group members. In other words, if a species forms a group and this species has the ability to learn something from other group members, then this species may have created a culture. Another important aspect of culture is the transmission of behavior from one generation to the next, implying that a species with culture must live in a perpetual group. Some insects live in groups, but each group disappears after a certain period, meaning that behaviors cannot be transmitted to the next generation in any media other than genes. The same is true for any random members of the same organism that form a group for a random period.An intensive study begun in 1948 by Japanese primatologists revealed that Japanese monkeys live in perpetual groups. The scientists adopted a method unique at the time, which named individual monkeys and revealed, for example, dominance relationships and social structure. In Japanese monkey society, females remain in a natal group and males leave to join other groups; that is, each group is maintained by maternal lineage.After examining the results of this early study, Imanishi (1952) suggested that Japanese monkeys may have their own culture. Imanishi’s suggestion spurred research conducted by colleagues and students, who studied cultural phenomena in nonhuman primates, as exemplified by the study of monkeys living in Koshima Islet that wash sweet potatoes (Kawamura 1954; Kawai 1965; Hirata et al. 2001). Half a century has passed since then, and researchers have accumulated knowledge about the behaviors of several primate species. They agree that among all the primate species, chimpanzees have an immense behavioral repertoire and that each community of chimpanzees has a different behavioral repertoire which cannot be explained by ecological differences; that is, chimpanzees have their own cultures (McGrew 1992; Whiten et al. 1999; Matsuzawa 2003).

Evolution of neonatal imitation.

Abstract: Humans do it. Chimps do it. Why shouldn’t monkeys do it, too? Mimicry exists throughout the animal kingdom, but imitation with a purpose—matching one’s behavior to others’ as a form of social learning—has been seen only in great apes. (Mockingbirds can imitate an impressive number of other birds’ songs, but they can’t mimic you sticking out your tongue like a chimp can.) This matching behavior likely helps individuals conform to social norms and perform actions in the proper context. It’s generally believed that monkeys do not imitate in this way. However, the discovery that rhesus monkeys have “mirror neurons”—neurons that fire both when monkeys watch another animal perform an action and when they perform the same action—suggests they possess the common neural framework for perception and action that is associated with imitation. Most studies exploring the early signs of matching behavior have focused on humans. A landmark 1977 study by Andrew Meltzoff and Keith Moore showed that 12- to 21-day-old infants could imitate adults who pursed their lips, stuck out their tongue, opened their mouth, and extended their fingers. They later found similar results in newborns, demonstrating that imitation is innate, not learned. A handful of studies on newborn chimps found a similar capacity for imitating human facial gestures. In a new study, Pier Ferrari, Stephen Suomi, and colleagues explored the possibility that imitation evolved earlier in the primate tree by studying neonatal imitation in rhesus monkeys, which split from the human lineage about 25 million years ago. They found that rhesus infants can indeed imitate a subset of human facial gestures—gestures the monkeys use to communicate. The first investigation of neonatal imitation outside the great ape lineage, their study suggests that the trait is not unique to great apes after all. Ferrari et al. tested 21 baby rhesus monkeys’ response to various experimental conditions at different ages (one, three, seven, and 14 days old). Infants were held in front of a researcher who began with a passive expression (the baseline condition) and then made one of several gestures, including tongue protrusion, mouth opening, lip smacking, and hand opening. Day-old infants rarely displayed mouth opening behavior, but smacked their lips frequently. When experimenters performed the mouth opening gesture, infants responded with increased lip smacking but did not increase any other behavior. None of the other stimuli produced significant responses. But by day 3, matched behaviors emerged: infants stuck out their tongues far more often in response to researchers’ tongue protrusions compared with control conditions, and smacked their lips far more often while watching researchers smacking theirs. (Watch an infant imitating mouth opening at DOI: 10.1371/journal.pbio.0040302.sv001.) By day 7, the monkeys tended to decrease lip smacking when humans performed the gesture, and by two weeks, all imitative behavior stopped. Infant rhesus monkeys, these results suggest, have a narrow imitation window that opens three days after birth, when they can reproduce human tongue protrusion and lip smacking. This imitation period is much longer in humans (two to three months) and chimps (about two months). It’s possible that rhesus babies show more varied and prolonged imitative behavior in response to mom or other monkeys than to human experimenters, who may not provide the most relevant biological cues. But this narrow window does comport with the development schedule of rhesus monkeys, which is much shorter than that of humans and chimps. Many questions remain about the neural mechanisms of neonatal imitation. The researchers argue that their results support a resonance mechanism linked to mirror neurons, which have recently been identified while monkeys observe others’ lip smacking and tongue protrusion. In this model, observing human mouth gestures directly activates mirror neurons in the monkeys’ brain, ultimately leading to a replication of the gesture. Human babies can imitate an adult’s facial gesture a day after seeing it, which may help them identify individuals. For rhesus monkeys, lip smacking (which often alternates with tongue protrusion) accompanies grooming sessions and signals affiliation—an important social cue for a species that is often described as “despotic and nepotistic.” Picking up these social gestures early in life may well facilitate the animal’s early social relations (primarily with the mother) and assimilation into the social fabric of the group, providing a mechanism for distinguishing friend from foe. It will be interesting to test the extent of imitation in monkeys with more complex social dynamics. While the social life of rhesus monkeys may not demand the more sophisticated repertoire of behaviors seen in great apes, they seem to be hard-wired for imitation just like apes.

Primates (Lemurs, Lorises, Tarsiers, Monkeys and Apes)

Abstract: The modern primates are a diverse order of mammals that includes lemurs, lorises, tarsiers, monkeys, apes and humans. They are united by a 65 My evolutionary history originally built on an adaptive foundation of tropical arboreality and so they share a collection of traits that are unique among mammals, such as an excellent sense of balance, acute vision, good hand–eye coordination, a large grasping first toe, prehensile feet and hands and a flexible, athletic limb anatomy. Primates also tend to live in relatively large social groups and often have correlatively enlarged brains. They almost always give birth to singletons that grow over a prolonged period, which is advantageous to cognitive development, learning and socialisation. Fossil nonhuman primates have been found on all continents but Australia and Antarctica. Primates have been important elements of tropical and subtropical faunas since mammals rebounded following the mass extinction that also promoted the demise of dinosaurs. Key Concepts: Primates are a highly diversified and successful order of mammals adapted to an arboreal, tropical lifestyle. There are three major surviving radiations – lemurs and lorises (strepsirhines) and Old World monkeys and apes (catarrhines) occur in Africa and Asia, and New World monkeys (platyrrhines) live in Central and South America – but many species are now threatened with extinction and the fourth radiation consists of only one genus, the tarsiers of eastern Asia. Although they arose from different ancestral stocks and display their own distinctive character, each radiation exhibits parallel evolution in dietary, locomotory and social adaptation to a treed environment, and all exhibit the universal primate characteristics of grasping big toes, some form of manual prehension and a preference for eating fruits – except for the exclusively predaceous tarsiers. Fossil primates are fairly well known and modern in appearance as early as the Eocene epoch, when many existing orders of mammals are also prevalent, but there is controversy as to where to set the primate–nonprimate boundary that influences how the older plesiadapiforms should be classified – in or outside of the primate order. The two largest primate clades, strepsirhines and haplorhines, one heavily reliant on the sense of smell and basically nocturnal and the other depending on vision and essentially diurnal, already existed approximately 55 Ma, but where and when anthropoids split from early haplorhines, and how the earliest members can be identified from limited sets of fossils, has not been determined. The New World platyrrhine monkeys are an early offshoot of anthropoids and only distantly related to Old World monkeys, a group that is more closely related to apes and humans. Increasing brain size as a correlate of increasing social group size is a pattern that evolved multiple times among anthropoids, irrespective of dietary preferences. The prolific early apes of the Miocene were eclipsed by the diversification of Old World monkeys in forested and open country habitats, especially in sub-Saharan Africa. Keywords: prosimians; strepsirhines; haplorhines; lemurs; lorises; tarsiers; anthropoids; new world monkeys; old world monkeys; apes

Squirrel Monkeys as an Example of Primate Nursery Medicine

Abstract: Providing nursery care for infant primates is one of the most challenging aspects of maintaining primates in captivity. Nursery infants must be protected from and treated for the many health problems to which they are vulnerable. At the same time, their developmental needs must be met through proper nutrition, environmental enrichment, and other strategies.