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PubMed1985

Teaching apes to ape language: explaining the imitative and nonimitative signing of a chimpanzee (Pan troglodytes).

Fifteen videotaped conversations of a chimpanzee signing with his trainers were examined in order to determine (a) whether the ape was using imitation to learn about new language forms as some human children do and (b) whether the ape's nonimitative utterances implied knowledge of linguistic structures. The answers to both questions were negative. The evidence suggests that the utterances lacked the semantic and syntactic organization found in the utterances of most children. Instead of learning to use signs as symbols for communicating propositional messages, the ape learned to use gestures as nonsymbolic instrumental responses under the stimulus control of objects in the signing context and verbal and nonverbal cues from the trainers. Other research now underway with chimpanzees may eventually reveal whether this performance is characteristic of chimpanzees in general or is the result of particular training strategies used to teach language to chimpanzees.

Animals↗

PubMed1985

Analysis of hematologic findings in healthy and sick adult chimpanzees (Pan troglodytes).

In order to assess the validity of interspecies extrapolation of hematological information, reference values obtained on 63 captive adult chimpanzees were compared with normal values for man. The discriminative power of both chimpanzee and human reference values was tested by the ability of each to identify abnormalities in the blood in 15 sick chimpanzees. The results indicated that human criteria could be applied to most chimpanzee red cell values but species differences were found in erythrocyte sedimentation rates and neutrophil counts.

Animals↗

PubMed1982

The binding characteristics of anti-Rho(D)-positive human and chimpanzee erythrocytes measured with 14C protein A.

The relation of the human erythrocyte Rho(D) antigen to its chimpanzee counterpart is currently unresolved. To explore this relation, we prepared 14C protein A to compare the binding parameters between human anti-Rho(D) and Rho(D)-positive human and chimpanzee erythrocytes. Double reciprocal plots of the binding in each case exhibited a straight line with intercepts indicating approximately the same numbers of Rho(D) binding sites for human and chimpanzee erythrocytes but an affinity that was 20 times greater for the human. This would indicate that the human and chimpanzee each have a single class of sites whose primary structure is very similar but sufficiently different to give the large divergence in affinity as measured by the human isoimmune antiserum.

Animals↗

PubMed1982

Non-A, non-B hepatitis in experimentally infected chimpanzees with the NIH strains F and H.

The NIH strains F and H of non-A, non-B hepatitis were studied by transmission to chimpanzees. They developed biochemical and ultrastructural evidences of non-A, non-B hepatitis. Chimpanzee's plasma containing the strain F was passaged further three times in the present study, and the results were identical to the original report made by SHIMIZU et al. In contrast to the original report, however, the prototype strain H inoculum or human plasma supposedly containing only the strain H, induced both SHIMIZU's cytoplasmic and nuclear changes in one chimpanzee. This result may pour further oil on the flame of recent controversy regarding the sequestration of the strains H and F, but we believe at present that the strains H and F are separate infectious agents. This is based on the fact that the strain F never induced SHIMIZU's nuclear changes, and our detection of an additional infectious agent of non-A, non-B hepatitis identical to the NIH strain H. We suspect the NIH strain H inoculum provided to us was contaminated by the strain F. The conclusion of controversy regarding the strain H should await for further studies including a further cross challenge study between the strain H and the strain F. Ultrastructural changes of the chimpanzee's liver associated with non-A, non-B hepatitis are described.

Alanine Transaminase↗

PubMed1980

Diuretic and uricosuric activity of 6,7-dichloro-2,3-dihydro-5-(2-thienylcarbonyl)benzofuran-2-carboxylic acid and stereoisomers in chimpanzee, dog and rat.

The racemate and the d-isomer of 6,7-dichloro-2,3-dihydro-5-(2-thienylcarbonyl)benzofuran-2-carboxylic acid exhibited diuretic activity in the chimpanzee, dog and rat. In the chimpanzee, the diuresis and natriuresis presumably resulted from a site of action in the thick ascending limb of Henle's loop. The l-isomer was uricosuric but devoid of any diuretic action in the chimpanzee and similarly was not diuretic in the dog and rat. Various proportions of the two isomers were tested in the chimpanzee in an attempt to produce an optimal diuretic and uricosuric profile. It was concluded that the racemic mixture, under these experimental conditions, was responsible for the most effective overall response. This is apparently the first time in which there is a distinct separation of diuretic and uricosuric actions in the enantiomers of a racemic diuretic uricosuric agent.

Animals↗

PubMed1993

The R-C-E-F blood group system of chimpanzees: serology and genetics.

Six chimpanzee alloimmune antibodies define 20 phenotypes of the R-C-E-F blood group system, the counterpart of the human Rh system. Of the several specificities of this system, the Rc constitutes the crucial link with human Rh since the reactions of some chimpanzee alloimmune anti-Rc sera with human red cells parallel those obtained with human anti-Rho reagents. Reciprocally, properly absorbed human anti-Rho sera detect Rc specificity on chimpanzee red cells. Tests with large panels of human monoclonal anti-D antibodies confirm the notion of shared epitopes between human alloantigen Rho(D) and chimpanzee alloantigen Rc.

Alleles↗

PubMed1994

Superinfection of chimpanzees carrying hepatitis C virus of genotype II/1b with that of genotype III/2a or I/1a.

Three chimpanzees persistently infected with hepatitis C virus of genotype II/1b were challenged with hepatitis C virus of genotype III/2a and 6 wk later with hepatitis C virus of genotype I/1a. They were tested for titers of total and genotype-specific hepatitis C virus RNA, as well as for serum transaminase levels, until 52 wk after the first challenge. One chimpanzee (CH489) with intermittent low hepatitis C virus RNA titers of genotype II/1b in serum was superinfected with hepatitis C virus of genotype III/2a between wk 1 and 7 after the challenge; superinfection was accompanied by fluctuating high transaminase levels. Later, the animal was superinfected with hepatitis C virus of genotype I/1a. Superinfection was accompanied by persistently high transaminase levels immediately after the challenge. Hepatitis C virus of genotype I/1a persisted, whereas hepatitis C virus of genotype II/1b was undetectable 22 wk after the challenge and thereafter. In another chimpanzee (CH353) with intermittent low hepatitis C virus RNA titers of genotype II/1b, hepatitis C virus of genotype III/2a induced fluctuating high levels of serum transaminases without revealing itself in serum. Then, HCV of genotype I/1a superinfected her, induced persistently high transaminase levels and took over HCV of genotype II/1b at 22 wk after the challenge and thereafter. The third chimpanzee (CH451) with persistently high HCV RNA titers of genotype II/1b did not reveal HCV RNA of genotype III/2a in serum after the challenge, although transaminases sharply increased. Low-titered HCV RNA of genotype I/1a was detected at 18 wk after the challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1976

[Conversion of chimpanzee O-erythrocytes into B-erythrocytes by human alpha galactosyltransferase].

The red blood cell antigens of the ABO system are not present in all the anthropïd Primates. The Chimpanzee, particularly, shows only the two genes A and O. The alpha-galactosyl transferase, present in the human sera of group B, has been used to fix a molecule of galactose on O red cells of Chimpanzee giving them a B specificity. If the B gene was present in the Chimpanzee it could consequently be expressed on the erythrocytes. This gene, probably present in an ancestor common to the anthropoïd apes and to Man disappeared in the Chimpanzee, perhaps at the origin of species.

ABO Blood-Group System↗

PubMed1999

Conserved CTL epitopes shared between HIV-infected human long-term survivors and chimpanzees.

Certain HIV-1 infected humans that do not progress to AIDS have been documented to share particular MHC class I alleles that appear to correlate with long-term survival. HIV-1-infected chimpanzees are relatively resistant to progression to AIDS. Out of a group of 10 chimpanzees with CTL activity and nonprogressive HIV-1 infection, 2 animals with prominent cytolytic CD3+CD8+ T cell responses to HIV-1 Ags were studied in detail. Characterization of these CTL revealed that they contained the granzymes A and B, T cell intracellular Ag-1, and perforin and induced calcium-dependent cytolysis that correlated with the presence of apoptotic nuclei in target cells. These CTL responses were directed against two gagpeptides, which were found to be identical to previously described epitopes recognized in the context of HLA-B27 and HLA-B57 molecules. The latter two restriction elements occur with increased frequency in human long-term survivor cohorts. Phylogenetic comparisons revealed that the chimpanzee restriction elements, Patr-B*02and -B*03, described here do not show any obvious similarity with the HLA-B*27 and -B*57 alleles, suggesting that CTL responses to HIV-1 in distinct primate species may be controlled by different types of HLA-B-like molecules. The CTL responses in these two chimpanzees are directed, however, against highly conserved epitopes mapping across the majority of HIV-1 clades.

Acquired Immunodeficiency Syndrome↗

PubMed2026

A new southern limit for the distribution of African great apes: sympatric western lowland gorilla (Gorilla gorilla gorilla) and central chimpanzee (Pan troglodytes troglodytes) confirmed in Mayombe National Park, Angola.

The distribution of African great apes has remained unconfirmed regarding their southern limit, particularly on the western side of the continent. IUCN maps include the Mayombe forest of Angola as part of the estimated distribution of western lowland gorillas (Gorilla gorilla gorilla) and central chimpanzees (Pan troglodytes troglodytes). However, until now no published evidence-based records had confirmed the continued presence of both species. The Mayombe forest is a key biodiversity hotspot and a potentially important stronghold for the conservation of great ape populations in Africa. Here, we report the first systematic evidence of both species in the Mayombe National Park, Cabinda, Angola. In 2023, a grid of camera traps was systematically deployed, producing the first visual records of gorillas and chimpanzees. Building on these findings, in 2024, a pilot survey including ad libitum field observations was carried out along exploratory trails to maximise data collection. The combination of these records identified a hotspot of great ape activity where six transects were established, and systematic direct and indirect evidence was documented. Chimpanzees were recorded more times across a broader range of evidence categories, while gorillas appeared less and seemed more spatially restricted. Notably, both species were detected at overlapping sites but never simultaneously, indicating sympatric coexistence with spatio-temporal partitioning. These findings confirm the southernmost predicted distribution of both species for this part of Africa, filling critical gaps in the understanding of great ape evolution and biogeography, and providing a baseline for the first demographic and ecological census of great apes in Angola.

Animals↗

PubMed1997

Interlimb coordination, gait, and neural control of quadrupedalism in chimpanzees.

Interlimb coordination is directly relevant to the understanding of the neural control of locomotion, but few studies addressing this topic for nonhuman primates are available, and no data exist for any hominoid other than humans. As a follow-up to Jungers and Anapol's ([1985] Am. J. Phys. Anthropol. 67:89-97) analysis on a lemur and talapoin monkey, we describe here the patterns of interlimb coordination in two chimpanzees as revealed by electromyography. Like the lemur and talapoin monkey, ipsilateral limb coupling in chimpanzees is characterized by variability about preferred modes within individual gaits. During symmetrical gaits, limb coupling patterns in the chimpanzee are also influenced by kinematic differences in hindlimb placement ("overstriding"). These observations reflect the neurological constraints placed on locomotion but also emphasize the overall flexibility of locomotor neural mechanisms. Interlimb coordination patterns are also species-specific, exhibiting significant differences among primate taxa and between primates and cats. Interspecific differences may be suggestive of phylogenetic divergence in the basic mechanisms for neural control of locomotion, but do not preclude morphological explanations for observed differences in interlimb coordination across species.

Animals↗

PubMed1999

Seed handling in chimpanzees (Pan troglodytes) and redtail monkeys (Cercopithecus ascanius): implications for understanding hominoid and cercopithecine fruit-processing strategies and seed dispersal.

Primates are confronted with an array of constraints in feeding on fruit, including the removal of adhesive, energy-rich pulp from seeds. In this paper, I discuss how primates meet this challenge and present data on the fruit-processing and seed-handling behavior of chimpanzees and redtail monkeys in Kibale National Park, Uganda. These data are then related to these species' services as seed dispersers. Particular attention was paid to the methods by which primates removed pulp from seeds, the density of seed clumps that they deposited (by spitting, dropping, or defecating) to the forest floor, and the distance seeds were moved from parent trees. Distance and density differences in chimpanzee and redtail seed dispersal resulted from distinct fruit-processing and seed-handling methods. It was observed, in general, that redtail monkeys engaged in fine oral processing and were seed spitters: most seeds were dispersed in close proximity to parent trees (84% of spat seeds < 10 m of parent tree), and deposited singly (100% seeds spat singly). In contrast, chimpanzees were coarse fruit processors and seed swallowers: seeds were defecated in denser clumps (e.g., a mean of 149 large seeds/dung sample and hundreds of small seeds/dung sample), far from parent trees. I evaluate the factors that shape patterns of fruit processing in hominoids and cercopithecines, and argue that the observed seed handling differences can be attributed to differences in digestive retention times, oral anatomy, and alternative mechanisms by which to avoid the cost of seed ballast.

Animals↗

PubMed1998

Isolation of a GB virus-related genome from a chimpanzee.

Recently, two new flaviviruses, GB virus A (GBV-A) and GB virus B (GBV-B), were identified in the plasma of a tamarin infected with the hepatitis GB agent. A third virus, GB virus C (GBV-C), was subsequently identified in humans. In the current study, representational difference analysis (RDA) was used to search for a new virus in the serum of a chimpanzee that developed acute resolving hepatitis following inoculation with a pool of chimpanzee plasma. The plasma pool originated from serial passages of a human sample containing virus-like particles. Numerous cDNA clones were obtained that exhibited 62-80% identity with GBV-C. With the exception of the extreme 5' and 3' ends, the complete viral genome was sequenced, revealing a single large open reading frame encoding a 2833 amino acid polyprotein that contains two envelope proteins, two proteases, a helicase, and an RNA-dependent RNA polymerase. Phylogenetic analysis of the new virus indicates that it is closely related to GBV-C, yet still sufficiently divergent as to be placed in a separate group, tentatively labeled GB virus Ctroglodytes (GBV-Ctro). Numerous human samples were screened by reverse transcriptase-polymerase chain reaction (RT-PCR), but GBV-Ctro sequence was not detected. However, a second chimpanzee inoculated with the same plasma pool was shown to develop a GBV-Ctro infection. Although isolated from an Old World primate with hepatitis, the primary host of GBV-Ctro and any association with disease remains to be determined.

Amino Acid Sequence↗

PubMed1999

Pneumatic processes in the temporal bone of chimpanzee (Pan troglodytes) and gorilla (Gorilla gorilla).

The ontogeny of human temporal bone pneumatization has been well studied from both comparative and clinical perspectives. While a difference in the extent of air cell distribution has been noted in our closest living relatives, chimpanzees and gorillas, the processes responsible have been relatively unexplored. To examine these processes, a large, age-graded series of hominoid skulls was radiographed and the progress of pneumatization recorded. Additionally, a subsample of 30 chimpanzees and 12 gorillas was subjected to high-resolution CT scanning. Neonatal specimens show a well-developed mastoid antrum, as well as a capacious hypotympanum extending into the petrous apex. In African apes, as in humans, the mastoid antrum serves as the focus for air cell expansion into the mastoid and immediately adjacent areas. In chimpanzees and gorillas, however, a pronounced lateral structure, described as the squamous antrum, serves as the focus of pneumatization for anterior structures such as the squamous and zygomatic. The diminution of this structure in Homo sapiens explains the difference in air cell distribution in these regions.

Anatomy, Cross-Sectional↗

PubMed1999

Mahale chimpanzees: grouping patterns and cycling females.

The social system of chimpanzees (Pan troglodytes schweinfurthii) is characterized by the fission-fusion of social groups. Several studies have reported that females are less gregarious than males. In the current study, adult female gregariousness depended on their reproductive state. Noncycling adult females (pregnant, lactating, or post reproductive) were observed in large bisexual parties less often than cycling adult females. On the other hand, cycling adult females were observed in large bisexual parties as often as males, regardless of their estrous state. More males were in parties that included cycling adult females with maximal genital swelling (estrous females) than in parties without them. Moreover, a bisexual party including more estrous females contained more males. These results suggest that large bisexual parties of chimpanzees are constructed by a dual mechanism. First, cycling adult females are attracted to parties that consist of the top ranking male and large numbers of adult and adolescent males. Second, adult and adolescent males that did not belong to parties originally are attracted by estrous females and join them. Thus, in Mahale Mountains National Park, Tanzania, bisexual parties of chimpanzees can be characterized as "parties for reproduction."

Animals↗

PubMed2001

Capturing and toying with hyraxes (Dendrohyrax dorsalis) by wild chimpanzees (Pan troglodytes) at Bossou, Guinea.

Chimpanzees (Pan troglodytes verus) were observed capturing and toying with western tree hyraxes (Dendrohyrax dorsalis, Order Hyracoidea) at Bossou, Guinea. An adolescent female carried one hyrax for 15 hr, slept with it in her nest, and groomed it. The captive was not consumed. Nearby adults ignored the hyrax. In another case, two adolescent males timidly inspected a small hyrax. These observations indicate that the chimpanzees at Bossou do not regard the hyrax as a prey animal, supporting the idea that lack of opportunity does not seem to be the only reason that chimpanzees do not consume an individual of a potential prey species.

Animals↗

PubMed1980

EMG of the interosseous and lumbrical muscles in the chimpanzee (Pan troglodytes) hand during locomotion.

The interosseous, lumbrical, and extensor digitorum communis muscles of the hunan hand constitute a complex apparatus that acts to move and stabilize the fingaers during grasping and manipulation. A telemetered electromyographic study of these muscles in chimpanzees was undertaken to determine whether use of the hand in locomotion and to maintain postures might be associated with functional roles different from those in humans. The manual interossei of chimpanzees are recruited in metacarpophalangeal flexion and in rapid interphalangeal joint extension. Slow digital extension can be accomplished solely by the extensor digitorum communis and lumbricals. The highly variable activity of the interossei during knuckle-walking is compatible with their roles as ab/adductors and rotators, but such movements could not be accurately assessed. It is concluded that the generalized suspensory and specialized terrestrial locomotion of the chimpanzee is not associated with major changes in the function of the manual interossei and lumbricals.

Animals↗

PubMed2001

Are bonobos (Pan paniscus) really more bipedal than chimpanzees (Pan troglodytes)?

Of the living apes, the chimpanzee (Pan troglodytes) and bonobo (Pan paniscus) are often presented as possible models for the evolution of hominid bipedalism. Bipedality in matched pairs of captive bonobos and chimpanzees was analyzed to test hypotheses for the evolution of bipedalism, derived from a direct referential model. There was no overall species difference in rates of bipedal positional behavior, either postural or locomotory. The hominoid species differed in the function or use of bipedality, with bonobos showing more bipedality for carrying and vigilance, and chimpanzees showing more bipedality for display.

Animals↗