Publications

prevalence of antibodies to alphaviruses and flaviviruses in free-ranging game animals and nonhuman primates in the greater congo basin.	vector-borne and zoonotic pathogens have comprised a significant proportion of the emerging infectious diseases in humans in recent decades. the role of many wildlife species as reservoirs for arthropod-borne viral pathogens is poorly understood. we investigated the exposure history of various african wildlife species from the congo basin to mosquito-borne flaviviruses and alphaviruses by testing archived serum samples. sera from 24 african forest buffalo (syncerus caffer nanus), 34 african elep ...	2013	23778608
distribution of recombination hotspots in the human genome--a comparison of computer simulations with real data.	recombination is the main cause of genetic diversity. thus, errors in this process can lead to chromosomal abnormalities. recombination events are confined to narrow chromosome regions called hotspots in which characteristic dna motifs are found. genomic analyses have shown that both recombination hotspots and dna motifs are distributed unevenly along human chromosomes and are much more frequent in the subtelomeric regions of chromosomes than in their central parts. clusters of motifs roughly fo ...	2013	23776462
gastrointestinal symbionts of chimpanzees in cantanhez national park, guinea-bissau with respect to habitat fragmentation.	one of the major factors threatening chimpanzees (pan troglodytes verus) in guinea-bissau is habitat fragmentation. such fragmentation may cause changes in symbiont dynamics resulting in increased susceptibility to infection, changes in host specificity and virulence. we monitored gastrointestinal symbiotic fauna of three chimpanzee subpopulations living within cantanhez national park (cnp) in guinea bissau in the areas with different levels of anthropogenic fragmentation. using standard coprosc ...	2013	23776090
chimpanzee-red colobus encounter rates show a red colobus population decline associated with predation by chimpanzees at ngogo.	chimpanzees (pan troglodytes) hunt various primates, but concentrate on red colobus monkeys (piliocolobus spp.) wherever the two species are sympatric. the extraordinarily large ngogo chimpanzee community in kibale national park, uganda, preys heavily on the local population of red colobus (p. tephrosceles). census data showed a steep decline in this population in the center of the chimpanzees' home range between 1975 and 2007 [lwanga et al., 2011; teelen, 2007b]. given no obvious change in food ...	2013	23775942
mhccluster, a method for functional clustering of mhc molecules.	the identification of peptides binding to major histocompatibility complexes (mhc) is a critical step in the understanding of t cell immune responses. the human mhc genomic region (hla) is extremely polymorphic comprising several thousand alleles, many encoding a distinct molecule. the potentially unique specificities remain experimentally uncharacterized for the vast majority of hla molecules. likewise, for nonhuman species, only a minor fraction of the known mhc molecules have been characteriz ...	2013	23775223
chimpanzees (pan troglodytes) can wait, when they choose to: a study with the hybrid delay task.	self-control has been studied in nonhuman animals using a variety of tasks. the inter-temporal choice (itc) task presents choices between smaller-sooner (ss) and larger-later (ll) options. using food amounts as rewards, this presents two problems: (a) choices of the ll option could either reflect self-control or instead result from animals' difficulty with pointing to smaller amounts of food; (b) there is no way to verify whether the subjects would not revert their choice for the ll option, if g ...	2014	23774954
the evolution of lineage-specific clusters of single nucleotide substitutions in the human genome.	genomic regions harboring large numbers of human-specific single nucleotide substitutions are of significant interest since they are potential genomic foci underlying the evolution of human-specific traits as well as human adaptive evolution. previous studies aimed to identify such regions either used pre-defined genomic locations such as coding sequences and conserved genomic elements or employed sliding window methods. such approaches may miss clusters of substitutions occurring in regions oth ...	2013	23770436
remembering in tool-use tasks in children and apes: the role of the information at encoding.	providing adults with relevant information (knowledge that they will be tested at some future time) increases motivation to remember. research has shown that it is more effective to have this information prior to, rather than after, an encoding phase. we investigated this effect in apes and children in the context of tool-use tasks. in experiment 1 we presented chimpanzees, orangutans, and bonobos with two tool-use tasks and three different two-tool sets. we had two conditions: prospective (pp) ...	2014	23767928
analysis of the beta-globin gene in dna of suspected thalassemic great apes.	dna was recovered from teeth of 2 great ape skeletons, pan troglodytes (ptr) and pongo pygmaeus (ppy), belonging to a 19th-century zoological collection. the skeletons presented morphological alterations possibly associated with β-thalassemia: ptr had deformation of the calvaria and oro-maxillo-facial bones with porotic hyperostosis and extended osteoporotic lesions of the skeleton, while ppy showed a general marked widening of the calvarial diploe but moderate osteoporotic signs on the post-cra ...	2013	23765979
differences in the early cognitive development of children and great apes.	there is very little research comparing great ape and human cognition developmentally. in the current studies we compared a cross-sectional sample of 2- to 4-year-old human children (n=48) with a large sample of chimpanzees and bonobos in the same age range (n=42, hereafter: apes) on a broad array of cognitive tasks. we then followed a group of juvenile apes (n=44) longitudinally over 3 years to track their cognitive development in greater detail. in skills of physical cognition (space, causalit ...	2014	23765870
computational analysis of four human adenovirus type 4 genomes reveals molecular evolution through two interspecies recombination events.	computational analysis of human adenovirus type 4 (hadv-e4), a pathogen that is the only hadv member of species e, provides insights into its zoonotic origin and molecular adaptation. its genome encodes a domain of the major capsid protein, hexon, from hadv-b16 recombined into the genome chassis of a simian adenovirus. genomes of two recent field strains provide a clue to its adaptation to the new host: recombination of a nf-i binding site motif, which is required for efficient viral replication ...	2013	23763770
fatal myocardial fibrosis in an aged chimpanzee (pan troglodytes).	a 36-year-old male chimpanzee (pan troglodytes) assigned to a life-long sign language communication project presented for sudden death. no other clinical or clinical pathological abnormalities were noted and given the signalment, death due to cardiac failure was suspected. necropsy findings revealed moderate cardiomegaly and other chronic age-related findings including focal renal tubular cystic dilation and gingival hyperplasia. histologic evaluation of the heart revealed interstitial fibrosing ...	2013	23762500
synaptogenesis and development of pyramidal neuron dendritic morphology in the chimpanzee neocortex resembles humans.	neocortical development in humans is characterized by an extended period of synaptic proliferation that peaks in mid-childhood, with subsequent pruning through early adulthood, as well as relatively delayed maturation of neuronal arborization in the prefrontal cortex compared with sensorimotor areas. in macaque monkeys, cortical synaptogenesis peaks during early infancy and developmental changes in synapse density and dendritic spines occur synchronously across cortical regions. thus, relatively ...	2013	23754422
impact of humans on long-distance communication behaviour of eastern chimpanzees (pan troglodytes schweinfurthii) in the northern democratic republic of the congo.	we systematically recorded all long-distance chimpanzee vocalizations and tree drums over a 26-month study period in 13 forest regions in the democratic republic of the congo. we found that the frequency of chimpanzee vocalizations and tree drums was considerably higher in the remote gangu forest than in other forest regions closer to human settlements and roads. we present evidence indicating that chimpanzees may reduce their levels of vocalizations in areas characterized by high levels of huma ...	2013	23751869
a cross-species study of gesture and its role in symbolic development: implications for the gestural theory of language evolution.	using a naturalistic video database, we examined whether gestures scaffold the symbolic development of a language-enculturated chimpanzee, a language-enculturated bonobo, and a human child during the second year of life. these three species constitute a complete clade: species possessing a common immediate ancestor. a basic finding was the functional and formal similarity of many gestures between chimpanzee, bonobo, and human child. the child's symbols were spoken words; the apes' symbols were l ...	2013	23750140
what counts for 'counting'? chimpanzees, pan troglodytes, respond appropriately to relevant and irrelevant information in a quantity judgment task.	nonhuman animals quantify all manner of things, and the way in which this is done is fairly well understood. however, little research has been conducted to determine how they know what is or is not relevant in the instances in which they quantify stimuli. we assessed how four chimpanzees chose between two sets of food items when the items were distributed across separate spatial arrays. each item was covered by a container, and then was revealed in sequence so that neither whole set was visible ...	2013	23750039
genome-wide inference of natural selection on human transcription factor binding sites.	for decades, it has been hypothesized that gene regulation has had a central role in human evolution, yet much remains unknown about the genome-wide impact of regulatory mutations. here we use whole-genome sequences and genome-wide chromatin immunoprecipitation and sequencing data to demonstrate that natural selection has profoundly influenced human transcription factor binding sites since the divergence of humans from chimpanzees 4-6 million years ago. our analysis uses a new probabilistic meth ...	2013	23749186
massive microrna sequence conservation and prevalence in human and chimpanzee introns.	human and chimpanzee introns contain numerous sequences strongly related to known microrna hairpin structures. the relative frequency is precisely maintained across all chromosomes, suggesting the possible co-evolution of gene networks dependent upon microrna regulation and with origins corresponding to the advent of primate transposable elements (tes). while the motifs are known to be derived from transposable elements, the most common are far more numerous than expected from the number of tes ...	2013	23747898
authority dependence and judgments of utilitarian harm.	three studies tested the conditions under which people judge utilitarian harm to be authority dependent (i.e., whether its right or wrongness depends on the ruling of an authority). in study 1, participants judged the right or wrongness of physical abuse when used as an interrogation method anticipated to yield useful information for preventing future terrorist attacks. the ruling of the military authority towards the harm was manipulated (prohibited vs. prescribed) and found to significantly in ...	2013	23747648
regional dna methylation differences between humans and chimpanzees are associated with genetic changes, transcriptional divergence and disease genes.	changes in gene expression have been proposed to have an important role in the evolutionary changes in phenotypes. interspecific changes in gene expression can result not only from genetic changes in regulatory regions but also from epigenetic changes in such regions. here we report the identification of genomic regions showing differences in dna methylation between humans and chimpanzees (termed s-dmrs for species-specific differentially methylated regions) on chromosomes 21 and 22. these regio ...	2013	23739127
novel mycobacterium tuberculosis complex isolate from a wild chimpanzee.	tuberculosis (tb) is caused by gram-positive bacteria known as the mycobacterium tuberculosis complex (mtbc). mtbc include several human-associated lineages and several variants adapted to domestic and, more rarely, wild animal species. we report an m. tuberculosis strain isolated from a wild chimpanzee in côte d'ivoire that was shown by comparative genomic and phylogenomic analyses to belong to a new lineage of mtbc, closer to the human-associated lineage 6 (also known as m. africanum west afri ...	2013	23735084
social network analysis of wild chimpanzees provides insights for predicting infectious disease risk.	1. heterogeneity in host association patterns can alter pathogen transmission and strategies for control. great apes are highly social and endangered animals that have experienced substantial population declines from directly transmitted pathogens; as such, network approaches to quantify contact heterogeneity could be crucially important for predicting infection probability and outbreak size following pathogen introduction, especially owing to challenges in collecting real-time infection data fo ...	2013	23734782
chimpanzees and bonobos exhibit emotional responses to decision outcomes.	the interface between cognition, emotion, and motivation is thought to be of central importance in understanding complex cognitive functions such as decision-making and executive control in humans. although nonhuman apes have complex repertoires of emotional expression, little is known about the role of affective processes in ape decision-making. to illuminate the evolutionary origins of human-like patterns of choice, we investigated decision-making in humans' closest phylogenetic relatives, chi ...	2013	23734175
developing a comprehensive and comparative questionnaire for measuring personality in chimpanzees using a simultaneous top-down/bottom-up design.	one effective method for measuring personality in primates is to use personality trait ratings to distill the experience of people familiar with the individual animals. previous rating instruments were created using either top-down or bottom-up approaches. top-down approaches, which essentially adapt instruments originally designed for use with another species, can unfortunately lead to the inclusion of traits irrelevant to chimpanzees or fail to include all relevant aspects of chimpanzee person ...	2013	23733359
event-based prospective memory in the rat.	people plan to act in the future when an appropriate event occurs, a capacity known as event-based prospective memory. prospective memory involves forming a representation of a planned future action, subsequently inactivating the representation, and ultimately reactivating it at an appropriate point in the future. recent studies suggest that monkeys, chimpanzees, and rats display elements of prospective memory, but it is uncertain if the full sequence (activation-inactivation-reactivation) that ...	2013	23727093
aps urges nih to revisit chimpanzee recommendations.		2013	23724588
age-related effects on malaria parasite infection in wild chimpanzees.	wild great apes are widely infected with a number of malaria parasites (plasmodium spp.). yet, nothing is known about the biology of these infections in the wild. using faecal samples collected from wild chimpanzees, we investigated the effect of age on plasmodium spp. detection rates. the data show a strong association between age and malaria parasite positivity, with significantly lower detection rates in adults. this suggests that, as in humans, individuals reaching adulthood have mounted an ...	2013	23720517
termite fishing by wild chimpanzees: new data from ugalla, western tanzania.	chimpanzees manufacture flexible fishing probes to fish for termites in issa, ugalla, western tanzania. these termite-fishing tools are similar in size and material to those used by long-studied communities of chimpanzees in western tanzania (pan troglodytes schweinfurthii) and in west africa (p. t. verus), but not central african populations (p. t. troglodytes). this report adds to the patchwork of evidence of termite-fishing tool use behaviour by chimpanzees across africa.	2014	23720026
how fairly do chimpanzees play the ultimatum game?	humans can behave fairly, but can other species? recently we tested chimpanzees on a classic human test for fairness, the ultimatum game, and found that they behaved similarly to humans. in humans, ultimatum game behavior is cited as evidence for a human sense of fairness. by that same logic, we concluded that chimpanzees behaved fairly in our recent study. however, we make a distinction between behavior and motivation. both humans and chimpanzees behaved fairly, but determining why they did so ...	2013	23713135
enhanced t cell function in a mouse model of human glycosylation.	clinical evidence for a more active immune response in humans compared with our closest hominid relative, the chimpanzee, includes the progression of hiv infection to aids, hepatitis b- and c-related inflammation, autoimmunity, and unwanted harmful immune responses to viral gene transfer vectors. humans have a unique mutation of the enzyme cmp-n-acetylneuraminic acid hydroxylase (cmah), causing loss of expression of the sialic acid neu5gc. this mutation, occurring 2 million years ago, likely alt ...	2013	23709682
a leopard ate a chimpanzee: first evidence from east africa.		2013	23706935
the hiv-1 pandemic: does the selective sweep in chimpanzees mirror humankind's future?	an hiv-1 infection progresses in most human individuals sooner or later into aids, a devastating disease that kills more than a million people worldwide on an annual basis. nonetheless, certain hiv-1-infected persons appear to act as long-term non-progressors, and elite control is associated with the presence of particular mhc class i allotypes such as hla-b27 or -b57. the hiv-1 pandemic in humans arose from the cross-species transmission of sivcpz originating from chimpanzees. chimpanzees, ho ...	2013	23705941
a scan for human-specific relaxation of negative selection reveals unexpected polymorphism in proteasome genes.	environmental or genomic changes during evolution can relax negative selection pressure on specific loci, permitting high frequency polymorphisms at previously conserved sites. here, we jointly analyze population genomic and comparative genomic data to search for functional processes showing relaxed negative selection specifically in the human lineage, whereas remaining evolutionarily conserved in other mammals. consistent with previous studies, we find that olfactory receptor genes display such ...	2013	23699470
genetic analysis of putative familial relationships in a captive chimpanzee (pan troglodytes) population.	twelve autosomal dinucleotide repeat loci were analyzed in chimpanzees genomes by dna amplification using primers designed for analysis of human loci. the markers span the entire length of human chromosomes 21 and 22. nine markers were polymorphic in chimpanzee as well, with a somewhat comparable level of polymorphism and allele size range. even in the presence of very limited information and in spite of missing samples, it was possible to reconstruct a complex pedigree and to provide molecular ...	2013	23697280
relying on chimpanzees for hepatitis research.		2013	23689445
biological races in humans.	races may exist in humans in a cultural sense, but biological concepts of race are needed to access their reality in a non-species-specific manner and to see if cultural categories correspond to biological categories within humans. modern biological concepts of race can be implemented objectively with molecular genetic data through hypothesis-testing. genetic data sets are used to see if biological races exist in humans and in our closest evolutionary relative, the chimpanzee. using the two most ...	2013	23684745
potential role of human-specific genes, human-specific micrornas and human-specific non-coding regulatory rnas in the pathogenesis of systemic sclerosis and sjögren's syndrome.	the etiology and pathogenesis of human autoimmune diseases remain unknown despite intensive investigations. although remarkable progress has been accomplished through genome wide association studies in the identification of genetic factors that may predispose to their occurrence or modify their clinical presentation to date no specific gene abnormalities have been conclusively demonstrated to be responsible for these diseases. the completion of the human and chimpanzee genome sequencing has open ...	2013	23684698
apes communicate about absent and displaced objects: methodology matters.	displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities), human infants display displaced reference but chimpanzees do not. here, we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced r ...	2014	23681052
a comparison of proximal humeral cancellous bone of great apes and humans.	the shoulder is the most mobile joint in the primate body, and is involved in both locomotor and manipulative activities. the presumed functional sensibility of trabecular bone can offer a way of decoding the activities to which the forelimbs of fossil primates were subjected. we examine the proximal humeral trabecular architecture in a relatively closely related group of similarly sized hominids (pongo pygmaeus, pan troglodytes, and homo sapiens), in order to evaluate the effect of diverging ha ...	2013	23680068
molecular determinants of hepatitis b and d virus entry restriction in mouse sodium taurocholate cotransporting polypeptide.	human hepatitis b virus (hbv) and its satellite virus, hepatitis d virus (hdv), primarily infect humans, chimpanzees, or tree shrews (tupaia belangeri). viral infections in other species are known to be mainly restricted at the entry level since viral replication can be achieved in the cells by transfection of the viral genome. sodium taurocholate cotransporting polypeptide (ntcp) is a functional receptor for hbv and hdv, and amino acids 157 to 165 of ntcp are critical for viral entry and likely ...	2013	23678176
behavioral recovery from tetraparesis in a captive chimpanzee.	an adult male chimpanzee living in a captive social group at the primate research institute of kyoto university developed acute tetraparesis. he was paralyzed and received intensive care and veterinary treatment as previously reported in miyabe-nishiwaki et al. (j med primatol 39:336-346, 2010). the behavioral recovery of the chimpanzee was longitudinally monitored using an index of upright posture between 0 and 41 months after the onset of tetraparesis. four phases were identified during the co ...	2013	23673560
personality structure in brown capuchin monkeys (sapajus apella): comparisons with chimpanzees (pan troglodytes), orangutans (pongo spp.), and rhesus macaques (macaca mulatta).	species comparisons of personality structure (i.e., how many personality dimensions and the characteristics of those dimensions) can facilitate questions about the adaptive function of personality in nonhuman primates. here we investigate personality structure in the brown capuchin monkey (sapajus apella), a new world primate species, and compare this structure to those of chimpanzees (pan troglodytes), orangutans (pongo spp.), and rhesus macaques (macaca mulatta). brown capuchins evolved behavi ...	2013	23668695
distribution of streptococcus troglodytae and streptococcus dentirousetti in chimpanzee oral cavities.	the aim of this study was to analyze the distribution and phenotypic properties of the indigenous streptococci in chimpanzee (pan troglodytes) oral cavities. eleven chimpanzees (aged from 9 to 44 years, mean ± sd, 26.9 ± 12.6 years) in the primate research institute of kyoto university were enrolled in this research and brushing bacterial samples collected from them. streptococci were isolated from the oral cavities of all chimpanzees. the isolates (n = 46) were identified as thirteen species by ...	2013	23668608
food washing and placer mining in captive great apes.	sweet potato washing and wheat placer mining in japanese macaques (macaca fuscata) are among the most well known examples of local traditions in non-human animals. the functions of these behaviors and the mechanisms of acquisition and spread of these behaviors have been debated frequently. prompted by animal caretaker reports that great apes [chimpanzees (pan troglodytes), bonobos (pan paniscus), gorillas (gorilla gorilla), and orangutans (pongo abelii)] at leipzig zoo occasionally wash their fo ...	2013	23665925
cytoplasmic organelle dna preferentially inserts into open chromatin.	dna transfer from chloroplasts and mitochondria to the nucleus is ongoing in eukaryotes but the mechanisms involved are poorly understood. mitochondrial dna was observed to integrate into the nuclear genome through dna double-strand break repair in nicotiana tabacum. here, 14 nuclear insertions of chloroplast dna (nupts) that are unique to oryza sativa subsp. indica were identified. comparisons with the preinsertion nuclear loci identified in the related subspecies, o. sativa subsp. japonica, wh ...	2013	23661564
hiv infection reveals widespread expansion of novel centromeric human endogenous retroviruses.	human endogenous retroviruses (hervs) make up 8% of the human genome. the herv-k (hml-2) family is the most recent group of these viruses to have inserted into the genome, and we have detected the activation of herv-k (hml-2) proviruses in the blood of patients with hiv-1 infection. we report that hiv-1 infection activates expression of a novel herv-k (hml-2) provirus, termed k111, present in multiple copies in the centromeres of chromosomes throughout the human genome yet not annotated in the m ...	2013	23657884
chimpanzee nesting patterns in savanna habitat: environmental influences and preferences.	data on chimpanzee (pan troglodytes) nesting patterns were collected in issa, ugalla, western tanzania. ugalla is one of the driest, most open, and seasonal habitats inhabited by chimpanzees. we investigated the physical characteristics of nests and trees used for nesting to understand environmental influences on nest building and identify the characteristics preferred by the chimpanzees and the basis for such preferences. we analyzed 2,167 nests and 1,523 nesting trees. most nests were built in ...	2013	23653164
a behavioral view on chimpanzee personality: exploration tendency, persistence, boldness, and tool-orientation measured with group experiments.	human and nonhuman animals show personality: temporal and contextual consistency in behavior patterns that vary among individuals. in contrast to most other species, personality of chimpanzees, pan troglodytes, has mainly been studied with non-behavioral methods. we examined boldness, exploration tendency, persistence and tool-orientation in 29 captive chimpanzees using repeated experiments conducted in an ecologically valid social setting. high temporal repeatability and contextual consistency ...	2013	23649750
neuroanatomical asymmetries and handedness in chimpanzees (pan troglodytes): a case for continuity in the evolution of hemispheric specialization.	many historical and contemporary theorists have proposed that population-level behavioral and brain asymmetries are unique to humans and evolved as a consequence of human-specific adaptations such as language, tool manufacture and use, and bipedalism. recent studies in nonhuman animals, notably primates, have begun to challenge this view. here, i summarize comparative data on neuroanatomical asymmetries in the planum temporale (pt) and inferior frontal gyrus (ifg) of humans and chimpanzees, regi ...	2013	23647534
discovery of pyrido[2,3-d]pyrimidine-based inhibitors of hcv ns5a.	efforts to improve the genotype 1a potency and pharmacokinetics of earlier naphthyridine-based hcv ns5a inhibitors resulted in the discovery of a novel series of pyrido[2,3-d]pyrimidine compounds, which displayed potent inhibition of hcv genotypes 1a and 1b in the replicon assay. sar in this system revealed that the introduction of amides bearing an additional 'e' ring provided compounds with improved potency and pharmacokinetics. introduction of a chiral center on the amide portion resulted in ...	2013	23642966
a comparison of antemortem tooth loss in human hunter-gatherers and non-human catarrhines: implications for the identification of behavioral evolution in the human fossil record.	middle and late pleistocene fossil hominin specimens with severe antemortem tooth loss are often regarded as evidence for the precocious evolution of human-like behaviors, such as conspecific care or cooking, in ancient hominin species. the goal of this project was to ask whether the theoretical association between antemortem tooth loss and uniquely human behaviors is supported empirically in a large skeletal sample of human hunter-gatherers, chimpanzees, orangutans, and baboons. binomial regres ...	2013	23640546
[chimpanzee veterinarian in sierra leone].		2013	23638561
primate laterality and the biology and evolution of human handedness: a review and synthesis.	we review evidence for and against lateralization of manual control, communication, visual processing, and auditory processing in nonhuman primates. compared to humans and some other vertebrate species, manual specialization in nonhuman primates is relatively weak. a right-bias in chimpanzees may exist, but is so weak that many studies using simple tasks fail to reveal it. slightly stronger biases may exist in baboons and chimpanzees for communicative signals in the manual and facial domains. se ...	2013	23631481
skeletal evidence for variable patterns of handedness in chimpanzees, human hunter-gatherers, and recent british populations.	previous studies have shown a strong correspondence between long bone bilateral asymmetry and reported handedness. here, we compare the pattern of asymmetry in mechanical properties of the humerus and second metacarpal of pan troglodytes, recent british industrial and medieval populations, and a broad range of human hunter-gatherers, to test whether technological variation corresponds with lateralization in bone function. the results suggest that p. troglodytes are left-lateralized in the morpho ...	2013	23627693
social grooming among wild bonobos (pan paniscus) at wamba in the luo scientific reserve, dr congo, with special reference to the formation of grooming gatherings.	chimpanzees (pan troglodytes) groom in gatherings in which many individuals may be connected via multiple chains of grooming and they often exchange partners with each other. they sometimes groom another while receiving grooming; that is, one animal can play two roles (i.e., groomer and groomee) simultaneously. although this feature of chimpanzees is notable from the viewpoint of the evolution of human sociality, information on our other closest living relative, the bonobo (pan paniscus), is sti ...	2013	23625035
brain aging in humans, chimpanzees (pan troglodytes), and rhesus macaques (macaca mulatta): magnetic resonance imaging studies of macro- and microstructural changes.	among primates, humans are uniquely vulnerable to many age-related neurodegenerative disorders. we used structural and diffusion magnetic resonance imaging (mri) to examine the brains of chimpanzees and rhesus monkeys across each species' adult lifespan, and compared these results with published findings in humans. as in humans, gray matter volume decreased with age in chimpanzees and rhesus monkeys. also like humans, chimpanzees showed a trend for decreased white matter volume with age, but thi ...	2013	23623601
age-related changes in the central nervous system in selected domestic mammals and primates.	aging is a process which operates at many levels of physiological, genetic and molecular organization and leads inevitably to death. brain macroscopic changes by mri investigation during aging were observed in humans and dogs but chimpanzees did not display significant changes. this suggestion led to the statement that brain aging is different in various species. although human brain changes, e.g. β-amyloid storage, neurofibrillary tangle formation, lipofuscin, are relatively well known, we are ...	2013	23619226
modulation of gb virus b rna abundance by microrna-122: dependence on and escape from microrna-122 restriction.	hepatitis c virus (hcv) rna forms an unusual interaction with human microrna-122 (mir-122) that promotes viral rna accumulation in cultured human liver cells and in the livers of infected chimpanzees. gb virus b (gbv-b) is a hepatotropic virus and close relative of hcv. thus, gbv-b has been used as a surrogate system to study hcv amplification in cultured cells and in infected tamarins. it was discovered that the 5'-terminal sequences of gbv-b rna, like hcv rna, forms an argonaute 2-mediated com ...	2013	23616647
a review of the institute of medicine's analysis of using chimpanzees in biomedical research.	we argue that the recommendations made by the institute of medicine's 2011 report, chimpanzees in biomedical and behavioral research: assessing the necessity, are methodologically and ethically confused. we argue that a proper understanding of evolution and complexity theory in terms of the science and ethics of using chimpanzees in biomedical research would have had led the committee to recommend not merely limiting but eliminating the use of chimpanzees in biomedical research. specifically, we ...	2014	23616243
increased morphological asymmetry, evolvability and plasticity in human brain evolution.	the study of hominin brain evolution relies mostly on evaluation of the endocranial morphology of fossil skulls. however, only some general features of external brain morphology are evident from endocasts, and many anatomical details can be difficult or impossible to examine. in this study, we use geometric morphometric techniques to evaluate inter- and intraspecific differences in cerebral morphology in a sample of in vivo magnetic resonance imaging scans of chimpanzees and humans, with special ...	2013	23615289
genetic and environmental contributions to the expression of handedness in chimpanzees (pan troglodytes).	most humans are right-handed and, like many behavioral traits, there is good evidence that genetic factors play a role in handedness. many researchers have argued that non-human animal limb or hand preferences are not under genetic control but instead are determined by random, non-genetic factors. we used quantitative genetic analyses to estimate the genetic and environmental contributions to three measures of chimpanzee handedness. results revealed significant population-level handedness for tw ...	2013	23615127
visual cues given by humans are not sufficient for asian elephants (elephas maximus) to find hidden food.	recent research suggests that domesticated species--due to artificial selection by humans for specific, preferred behavioral traits--are better than wild animals at responding to visual cues given by humans about the location of hidden food. \although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses) and wild (including wolves and chimpanzees) animals, there is also evidence that exposure to humans positively influences the ability of both wild a ...	2013	23613804
measurements of salivary alpha amylase and salivary cortisol in hominoid primates reveal within-species consistency and between-species differences.	salivary alpha amylase (saa) is the most abundant enzyme in saliva. studies in humans found variation in enzymatic activity of saa across populations that could be linked to the copy number of loci for salivary amylase (amy1), which was seen as an adaptive response to the intake of dietary starch. in addition to diet dependent variation, differences in saa activity have been related to social stress. in a previous study, we found evidence for stress-induced variation in saa activity in the bonob ...	2013	23613746
a divergent clade of circular single-stranded dna viruses from pig feces.	using metagenomics and molecular cloning methods, we characterized five novel small, circular viral genomes from pig feces that are distantly related to chimpanzee and porcine stool-associated circular viruses, (chiscv and poscv1). phylogenetic analysis placed these viruses into a highly divergent clade of this rapidly growing new viral family. this new clade of viruses, provisionally named porcine stool-associated circular virus 2 and 3 (poscv2 and poscv3), encodes a stem-loop structure (presum ...	2013	23612924
the end of life, the ends of life: an anthropological view.	all known human societies have a worldview that deserves to be called religion; all religions must explain death. anthropologists study the diversity of religious systems, present and past, in order to understand what is common to humanity. rather than starting from the view of a particular revelation or set of doctrines, the anthropologist tries to step outside his or her own subjective worldview and identify patterns in the evolution of human thinking about the reality of physical death. are h ...	2011	23610511
sex differences in tool use acquisition in bonobos (pan paniscus).	all the great ape species are known tool users in both the wild and captivity, although there is great variation in ability and behavioral repertoire. differences in tool use acquisition between chimpanzees and gorillas have been attributed to differing levels of social tolerance as a result of differences in social structure. chimpanzees also show sex differences in acquisition and both chimpanzees and bonobos demonstrate a female bias in tool use behaviors. studies of acquisition are limited i ...	2013	23606188
mapping putative hubs in human, chimpanzee and rhesus macaque connectomes via diffusion tractography.	mapping anatomical brain networks with graph-theoretic analysis of diffusion tractography has recently gained popularity, because of its presumed value in understanding brain function. however, this approach has seldom been used to compare brain connectomes across species, which may provide insights into brain evolution. here, we employed a data-driven approach to compare interregional brain connections across three primate species: 1) the intensively studied rhesus macaque, 2) our closest livin ...	2013	23603286
handedness is more than laterality: lessons from chimpanzees.	is human handedness unique? that is, do our nearest living relations, chimpanzee and bonobo (pan spp.) show species-wide handedness, as is seen in living homo sapiens? the answer may depend on definition: handedness (congruence across subjects and across tasks) should be distinguished from hand preference (within subject and task), manual specialization (within subject, across tasks), and task specialization (across subjects, within task). comparison is required at both population and species le ...	2013	23601007
the protocadherin 11x/y (pcdh11x/y) gene pair as determinant of cerebral asymmetry in modern homo sapiens.	annett's right-shift theory proposes that human cerebral dominance (the functional and anatomical asymmetry or torque along the antero-posterior axis) and handedness are determined by a single "right-shift" gene. familial transmission of handedness and specific deviations of cerebral dominance in sex chromosome aneuploidies implicate a locus within an x-y homologous region of the sex chromosomes. the xq21.3/yp11.2 human-specific region of homology includes the protocadherin 11x/y (pcdh11x/y) gen ...	2013	23600975
laterality in the gestural communication of wild chimpanzees.	we examined hand preference in the intentional gestural communication of wild chimpanzees in the budongo forest, uganda. individuals showed some tendency to be lateralized, although less than has been reported for begging and pointing gestures in captivity; on average, their absolute bias was around 0.25 (where 1.0 represents complete right- or left-hand use and 0.0 represents no bias). lateralization was incomplete even in individuals with major manual disabilities. where individuals had a stro ...	2013	23600943
human-specific herv-k insertion causes genomic variations in the human genome.	human endogenous retroviruses (herv) sequences account for about 8% of the human genome. through comparative genomics and literature mining, we identified a total of 29 human-specific herv-k insertions. we characterized them focusing on their structure and flanking sequence. the results showed that four of the human-specific herv-k insertions deleted human genomic sequences via non-classical insertion mechanisms. interestingly, two of the human-specific herv-k insertion loci contained two herv-k ...	2013	23593260
balancing selection on a regulatory region exhibiting ancient variation that predates human-neandertal divergence.	ancient population structure shaping contemporary genetic variation has been recently appreciated and has important implications regarding our understanding of the structure of modern human genomes. we identified a ∼36-kb dna segment in the human genome that displays an ancient substructure. the variation at this locus exists primarily as two highly divergent haplogroups. one of these haplogroups (the ne1 haplogroup) aligns with the neandertal haplotype and contains a 4.6-kb deletion polymorphis ...	2013	23593015
sequencing and comparative analysis of the gorilla mhc genomic sequence.	major histocompatibility complex (mhc) genes play a critical role in vertebrate immune response and because the mhc is linked to a significant number of auto-immune and other diseases it is of great medical interest. here we describe the clone-based sequencing and subsequent annotation of the mhc region of the gorilla genome. because the mhc is subject to extensive variation, both structural and sequence-wise, it is not readily amenable to study in whole genome shotgun sequence such as the recen ...	2013	23589541
seroprevalence of neutralizing antibodies to human adenoviruses type-5 and type-26 and chimpanzee adenovirus type-68 in healthy chinese adults.	replication-defective adenoviruses have been utilized as candidate vaccine vectors. however, clinical application of the best-studied human adenovirus type-5 (adhu5) is limited by the high prevalence of preexisting neutralizing antibodies resulting from natural infection. therefore, rare adenovirus serotypes, such as human adenovirus type-26 (adhu26) and chimpanzee adenovirus type-68 (adc68), have been employed as substitutes for adhu5. however, few studies have described the epidemiology of pre ...	2013	23588735
a demographic analysis of primate research in the united states.	an analysis of primate research in the usa, including the number and species of non-human primates used, types of research, levels of invasiveness, housing conditions and funding, is an important step in addressing various concerns (ethical and scientific) surrounding primate research. an analysis of monkey and chimpanzee research, conducted by the humane society of the united states (hsus), demonstrated that the usa uses more non-human primates (including great apes) in research per year, than ...	2004	23577480
ontogeny and phylogeny of language.	how did language evolve? a popular approach points to the similarities between the ontogeny and phylogeny of language. young children's language and nonhuman primates' signing both appear formulaic with limited syntactic combinations, thereby suggesting a degree of continuity in their cognitive abilities. to evaluate the validity of this approach, as well as to develop a quantitative benchmark to assess children's language development, i propose a formal analysis that characterizes the statistic ...	2013	23576720
taï chimpanzees use botanical skills to discover fruit: what we can learn from their mistakes.	fruit foragers are known to use spatial memory to relocate fruit, yet it is unclear how they manage to find fruit in the first place. in this study, we investigated whether chimpanzees (pan troglodytes verus) in the taï national park make use of fruiting synchrony, the simultaneous emergence of fruit in trees of the same species, which can be used together with sensory cues, such as sight and smell, to discover fruit. we conducted observations of inspections, the visual checking of fruit availab ...	2013	23576098
comprehensively identifying and characterizing the missing gene sequences in human reference genome with integrated analytic approaches.	the human reference genome is still incomplete and a number of gene sequences are missing from it. the approaches to uncover them, the reasons causing their absence and their functions are less explored. here, we comprehensively identified and characterized the missing genes of human reference genome with rna-seq data from 16 different human tissues. by using a combined approach of genome-guided transcriptome reconstruction coupled with genome-wide comparison, we uncovered 3.78 and 2.37 mb trans ...	2013	23572138
plasmodium falciparum-like parasites infecting wild apes in southern cameroon do not represent a recurrent source of human malaria.	wild-living chimpanzees and gorillas harbor a multitude of plasmodium species, including six of the subgenus laverania, one of which served as the progenitor of plasmodium falciparum. despite the magnitude of this reservoir, it is unknown whether apes represent a source of human infections. here, we used plasmodium species-specific pcr, single-genome amplification, and 454 sequencing to screen humans from remote areas of southern cameroon for ape laverania infections. among 1,402 blood samples, ...	2013	23569255
chimpanzee responders still behave like rational maximizers.		2013	23564347
obstructive uropathy secondary to uterine leiomyoma in a chimpanzee (pan troglodytes).	complications due to uterine leiomyomata in chimpanzees have rarely been documented. here we describe a female chimpanzee that developed severe hydronephrosis in the right kidney due to leiomyoma. because hysterectomy did not alleviate the hydronephrosis, nephrectomy was elected. after these procedures, the chimpanzee is doing well. leiomyomata screening programs with treatment algorithms are a useful component of a comprehensive chimpanzee program.	2012	23561890
development of chimpanzee adenoviruses as vaccine vectors: challenges and successes emerging from clinical trials.	replication-defective chimpanzee adenovirus vectors are emerging as a promising new class of genetic vaccine carriers. chimpanzee adenovirus vectors have now reached the clinical stage and appear to be endowed with all the properties needed for human vaccine development, including high quality and magnitude of the immune response induced against the encoded antigens, good safety and ease of manufacturing on a large-scale basis. here the authors review the recent findings of this novel class of a ...	2013	23560919
population structure in a comprehensive genomic data set on human microsatellite variation.	over the past two decades, microsatellite genotypes have provided the data for landmark studies of human population-genetic variation. however, the various microsatellite data sets have been prepared with different procedures and sets of markers, so that it has been difficult to synthesize available data for a comprehensive analysis. here, we combine eight human population-genetic data sets at the 645 microsatellite loci they share in common, accounting for procedural differences in the producti ...	2013	23550135
head-mounted eye tracking of a chimpanzee under naturalistic conditions.	this study offers a new method for examining the bodily, manual, and eye movements of a chimpanzee at the micro-level. a female chimpanzee wore a lightweight head-mounted eye tracker (60 hz) on her head while engaging in daily interactions with the human experimenter. the eye tracker recorded her eye movements accurately while the chimpanzee freely moved her head, hands, and body. three video cameras recorded the bodily and manual movements of the chimpanzee from multiple angles. we examined how ...	2013	23544099
ketamine-medetomidine regimen for chemical immobilisation of free-ranging chimpanzees (pan troglodytes schweinfurthii) in uganda.		2013	23542655
targeting mirnas to treat hepatitis c virus infections and liver pathology: inhibiting the virus and altering the host.	hepatitis c virus (hcv) infection-induced liver disease is a growing problem worldwide, and is the primary cause of liver failure requiring liver transplantation in north america. improved therapeutic strategies are required to control and possibly eradicate hcv infections, and to modulate hcv-induced liver disease. cellular micrornas anneal to and regulate mrna translation and stability and form a regulatory network that modulates virtually every cellular process. thus, mirnas are promising cel ...	2013	23541631
transmission of mycobacterium tuberculosis from an asian elephant (elephas maximus) to a chimpanzee (pan troglodytes) and humans in an australian zoo.	mycobacterium tuberculosis is primarily a pathogen of humans. infections have been reported in animal species and it is emerging as a significant disease of elephants in the care of humans. with the close association between humans and animals, transmission can occur. in november 2010, a clinically healthy asian elephant in an australian zoo was found to be shedding m. tuberculosis; in september 2011, a sick chimpanzee at the same zoo was diagnosed with tuberculosis caused by an indistinguishabl ...	2013	23537562
the malagarasi river does not form an absolute barrier to chimpanzee movement in western tanzania.	the malagarasi river has long been thought to be a barrier to chimpanzee movements in western tanzania. this potential geographic boundary could affect chimpanzee ranging behavior, population connectivity and pathogen transmission, and thus has implications for conservation strategies and government policy. indeed, based on mitochondrial dna sequence comparisons it was recently argued that chimpanzees from communities to the north and to the south of the malagarasi are surprisingly distantly rel ...	2013	23536841
vaccination to conserved influenza antigens in mice using a novel simian adenovirus vector, panad3, derived from the bonobo pan paniscus.	among approximately 1000 adenoviruses from chimpanzees and bonobos studied recently, the pan adenovirus type 3 (panad3, isolated from a bonobo, pan paniscus) has one of the best profiles for a vaccine vector, combining potent transgene immunogenicity with minimal pre-existing immunity in the human population. in this study, we inserted into a replication defective panad3 a transgene expressing a fusion protein of conserved influenza antigens nucleoprotein (np) and matrix 1 (m1). we then studied ...	2013	23536756
spontaneous synchronized tapping to an auditory rhythm in a chimpanzee.	humans actively use behavioral synchrony such as dancing and singing when they intend to make affiliative relationships. such advanced synchronous movement occurs even unconsciously when we hear rhythmically complex music. a foundation for this tendency may be an evolutionary adaptation for group living but evolutionary origins of human synchronous activity is unclear. here we show the first evidence that a member of our closest living relatives, a chimpanzee, spontaneously synchronizes her move ...	2013	23535698
the human cd8β m-4 isoform dominant in effector memory t cells has distinct cytoplasmic motifs that confer unique properties.	the cd8 co-receptor influences t cell recognition and responses in both anti-tumor and anti-viral immunity. during evolution in the ancestor of humans and chimpanzees, the cd8b gene acquired two additional exons. as a result, in humans, there are four cd8β splice variants (m1 to m4) that differ in their cytoplasmic tails. the m-1 isoform which is the equivalent of murine cd8β, is predominantly expressed in naïve t cells, whereas, the m-4 isoform is predominantly expressed in effector memory t ce ...	2013	23533620
understanding geographic origins and history of admixture among chimpanzees in european zoos, with implications for future breeding programmes.	despite ample focus on this endangered species, conservation planning for chimpanzees residing outside africa has proven a challenge because of the lack of ancestry information. here, we analysed the largest number of chimpanzee samples to date, examining microsatellites in >100 chimpanzees from the range of the species in africa, and 20% of the european zoo population. we applied the knowledge about subspecies differentiation throughout equatorial africa to assign origin to chimpanzees in the l ...	2013	23531981
stable isotope evidence of meat eating and hunting specialization in adult male chimpanzees.	observations of hunting and meat eating in our closest living relatives, chimpanzees (pan troglodytes), suggest that among primates, regular inclusion of meat in the diet is not a characteristic unique to homo. wild chimpanzees are known to consume vertebrate meat, but its actual dietary contribution is, depending on the study population, often either unknown or minimal. constraints on continual direct observation throughout the entire hunting season mean that behavioral observations are limited ...	2013	23530185
the evolution of brains from early mammals to humans.	the large size and complex organization of the human brain makes it unique among primate brains. in particular, the neocortex constitutes about 80% of the brain, and this cortex is subdivided into a large number of functionally specialized regions, the cortical areas. such a brain mediates accomplishments and abilities unmatched by any other species. how did such a brain evolve? answers come from comparative studies of the brains of present-day mammals and other vertebrates in conjunction with i ...	2012	23529256
safety and immunogenicity of heterologous prime-boost immunisation with plasmodium falciparum malaria candidate vaccines, chad63 me-trap and mva me-trap, in healthy gambian and kenyan adults.	heterologous prime boost immunization with chimpanzee adenovirus 63 (chad63) and modified vaccinia virus ankara (mva) vectored vaccines is a strategy recently shown to be capable of inducing strong cell mediated responses against several antigens from the malaria parasite. chad63-mva expressing the plasmodium falciparum pre-erythrocytic antigen me-trap (multiple epitope string with thrombospondin-related adhesion protein) is a leading malaria vaccine candidate, capable of inducing sterile protec ...	2013	23526949
different ontogenetic patterns of testosterone production reflect divergent male reproductive strategies in chimpanzees and bonobos.	male reproductive effort is often strongly related to levels of the steroid hormone testosterone. however, little research has examined whether levels of testosterone throughout development might be tied to individual or species differences in the reproductive strategies pursued by adult males. here, we tested the hypothesis that inter-specific differences in male reproductive strategy are associated with differences in the pattern of testosterone production throughout early life and puberty. we ...	2013	23523480
the heterochromatic chromosome caps in great apes impact telomere metabolism.	in contrast with the limited sequence divergence accumulated after separation of higher primate lineages, marked cytogenetic variation has been associated with the genome evolution in these species. studying the impact of such structural variations on defined molecular processes can provide valuable insights on how genome structural organization contributes to organismal evolution. here, we show that telomeres on chromosome arms carrying subtelomeric heterochromatic caps in the chimpanzee, which ...	2013	23519615
regional and hemispheric variation in cortical thickness in chimpanzees (pan troglodytes).	recent advances in structural magnetic resonance imaging technology and analysis now allows for accurate in vivo measurement of cortical thickness, an important aspect of cortical organization that has historically only been conducted on postmortem brains. in this study, for the first time, we examined regional and lateralized cortical thickness in a sample of 71 chimpanzees for comparison with previously reported findings in humans. we also measured gray and white matter volumes for each subjec ...	2013	23516289
the transmembrane domain of hiv-1 vpu is sufficient to confer anti-tetherin activity to sivcpz and sivgor vpu proteins: cytoplasmic determinants of vpu function.	the acquisition of effective vpu-mediated anti-tetherin activity to promote virion release following transmission of sivcpzptt from central chimpanzees (pan troglodytes troglodytes) to humans distinguishes pandemic hiv-1 group m strains from non-pandemic group n, o and p viruses and may have been a prerequisite for their global spread. some functional motifs in the cytoplasmic region of hiv-1 m vpus proposed to be important for anti-tetherin activity are more frequently found in the vpu proteins ...	2013	23514615
language-trained chimpanzees (pan troglodytes) name what they have seen but look first at what they have not seen.	metacognition can be defined as knowing what one knows, and the question of whether nonhuman animals are metacognitive has driven an intense debate. we tested 3 language-trained chimpanzees in an information-seeking task in which the identity of a food item was the critical piece of information needed to obtain the food. the chimpanzees could either report the identity of the food immediately or first check a container in which the food had been hidden. in two experiments, the chimpanzees were s ...	2013	23508741