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PubMed1984

A vocabulary test for chimpanzees (Pan troglodytes).

Chimpanzees can communicate in American Sign Language (ASL) to independent human observers whose only source of information is the ASL signs of the chimpanzees. A vocabulary test was presented to 4 cross-fostered chimpanzees (4-6 years old). Thirty-five-millimeter color slides were projected on a screen that could be seen by the chimpanzee subject but not by the human observers. There were two observers: O1 was the questioner in the testing room with the subject; O2 was in a different room. Neither observer could see the other, or the responses of the other observer. O1 and O2 agreed in their readings of both correct and incorrect signs, and most of the signs were the correct ASL names of the slides. In order to show that the chimpanzees were naming natural language categories--that the sign DOG could refer to any dog, FLOWER to any flower, SHOE to any shoe--each test trial was a first trial in that test slides were presented only once. Analysis of errors showed that two aspects of the signs, gestural form and conceptual category, governed the distribution of errors.

Animals↗
PubMed1980

Viruslike particles in a plasma fraction (fibrinogen) and in the circulation of apparently healthy blood donors capable of inducing non-A/non-B hepatitis in humans and chimpanzees.

Two patients who had received a fibrinogen preparation contracted hepatitis of non-A/non-B etiology 3 and 8 wk after the injection. A chimpanzee inoculated with the same preparation developed hepatitis 11 wk later, with an increase in SGPT and a liver pathology compatible with acute viral hepatitis. His preacute serum containing the presumptive etiologic agent induced hepatitis in another chimpanzee. Electron microscopic observation of the liver of these chimpanzees biopsied during preacute and acute stages revealed peculiar tubular structures composed of two unit membranes with electron-opaque material in between. Using the serum obtained from infected chimpanzees at convalescence as an antibody reagent, viruslike particles were identified in the fibrinogen preparation by immune electron microscopy. When the serum of 100 apparently healthy blood donors with SGPT value of 80 Karmen units/ml or higher was tested for viruslike particles, eight were found to be positive. Furthermore, one of these sera, when a 5-ml amount was injected into each of two chimpanzees, induced hepatitis with viruslike particles in the circulation and characteristic tubular changes in the liver. On the basis of the results obtained, the viruslike particles in the fibrinogen preparation, as well as in the circulation of apparently healthy donors, were capable of inducing hepatitis of non-A/non-B category with a liver pathology characterized by tubular structures. The detection of non-A/non-B viral particles, especially when refined to routine laboratory tests, may open the way for the specific diagnosis, exclusion of contaminated blood from transfusion, and eventual prophylaxis by vaccination.

Alanine Transaminase↗
PubMed1980

Reproductive behaviour of wild chimpanzees in the Gombe National Park, Tanzania.

(1) The reproductive behaviour of chimpanzees in the Gombe National Park, Tanzania, was studied for 16 months and additional information came from 19 years of demographic data collected by Dr Jane Goodall and members of the Gombe Stream Research Centre. (2) The mating system of the Gombe chimpanzees comprises 3 mating patterns: (a) opportunistic, non-competitive mating, when an oestrous female may be mated by all the males in the group; (b) possessiveness, when a male forms a special short-term relationship with an oestrous female and may prevent lower ranking males from copulating with her; and (c) consortships, when a male and a female leave the group and remain alone, actively avoiding other chimpanzees. While males took the initiative in possessive behaviour and consortships, females had to co-operate for a successful relationship to develop. (3) Data from 14 conceptions indicated that the majority of females (9) became pregnant while participating in the restrictive mating patterns, possessiveness and consorting. Adult males showed differential frequencies of involvement in the restrictive mating patterns. The following male characteristics showed significant, positive correlations with participation in the restrictive patterns: (a) the amount of time spent in the same group as oestrous females, (b) the proportion of that time spent grooming oestrous females, and (c) the frequency with which males shared food with females. Dominance ranks of the adult males showed no consistent correlation with involvement in the restrictive patterns, but it was clear that the most dominant male did gain an advantage. He was the only male able to monopolize oestrous females by showing possessiveness. (4) Developmental and demographic data from observations for 19 years show that female chimpanzees have a very limited reproductive potential. Females reached menarche at about 11 years of age but this was followed by a period of adolescent sterility of median length 26 months. Each birth, if the infant survived, was followed by a long period of lactational amenorrhoea of median duration 42 months. The mean inter-birth interval of the Gombe chimpanzees was 5 years 8 months. Thus, the theoretical lifetime reproductive potential of females is 5-6 offspring who survive to weaning. Data on achieved reproductive success showed that females had a median of 3 births in their lifetime, with only 2 offspring surviving to reproductive age.

Animals↗
PubMed1978

The major histocompatibility complex of chimpanzees: identification of several new antigens controlled by the A and B loci of ChLa.

The serology and genetics of 17 serologically defined tissue antigens of chimpanzees is described. Analysis of their distribution in 200 unrelated chimpanzees and their segregation in a large number of chimp families suggests that 14 of the antigens are controlled by two closely linked loci: seven by the A and seven by the B locus of ChLA. Typing of chimpanzees with human alloantisera revealed that several of those A and B locus antigens of ChLA are the chimp's serological counterparts of A and B locus antigens of the human HLA system, respectively. One of the newly discovered chimp antigens may be defined by a "third series" of ChLA, most likely the chimp's analogue of the human HLA-C series. The probable existence of a ChLA-linked D locus of chimpanzees and similarities between D-locus and Ia-locus (DRw) antigens of chimpanzee and man, are also briefly discussed.

Animals↗
PubMed1982

Chimpanzee holding, rehabilitation and breeding: facilities design and colony management.

A multipurpose chimpanzee facility was designed and constructed to provide the unique housing requirements of rehabilitating laboratory-raised, behaviorally-deficient chimpanzees. The housing complex provided quarantine facilities, single or group housing for long-term holding, and semi-free-ranging compounds for established breeding groups. The facilities were designed to accommodate 170 animals of diverse ages and group configurations. Reproductive performance of the chimpanzees resulted in the production of 0.41 live infants per adult female year. Information was also given on the care, diet, maintenance, health status, handling, and rehabilitation of the chimpanzee. Development of this facility has made it practical to house large numbers of chimpanzees economically and conveniently in an enriched environment which promotes breeding and contributes to the survival of this irreplaceable animal model.

Animal Husbandry↗
PubMed1995

Paralytic illness resembling inflammatory polyradiculoneuropathy in a chimpanzee.

An adult male chimpanzee housed in an outdoor corral with a group of other chimpanzees had an acute onset of ascending motor paresis that progressed to flaccid tetraplegia over 3 days. Tendon reflexes were weak, and CSF protein concentration was high. The chimpanzee regained normal mobility over several months. This chimpanzee's ascending, symmetrical, monophasic, flaccid paralytic illness, with albuminocytologic dissociation in CSF, and recovery following supportive treatment, was characteristic of inflammatory polyradiculoneuropathy, known as Guillain-Barré syndrome in human beings. Coonhound paralysis and experimentally induced allergic neuritis are the counterparts in dogs and laboratory animals, respectively, of the syndrome. In human beings, the syndrome is apparently immunologically mediated, as it is known to develop after bacterial and viral infections, vaccinations, and surgery or injury. The chimpanzee of this report had been given a rabies vaccination and had been treated for dental abscess 12 days prior to onset of signs, and had been inoculated with material containing neuronal antigens 20 years prior to onset of signs.

Animals↗
PubMedDate not supplied

The resistance of HIV-infected chimpanzees to progression to AIDS correlates with absence of HIV-related T-cell dysfunction.

Differences in the in vivo and in vitro responses of T lymphocytes from chimpanzees and human subjects were compared for evidence of HIV-1 related T-cell dysfunction. There was no increased level of programmed cell death (PCD) in HIV-1 infected chimpanzees in contrast to asymptomatic individuals. Anergy could be induced with HIV-1 gp120 in human but not chimpanzee TH lymphocytes, however in vitro infection of chimpanzee TH cultures with HIV-1 resulted in complete lysis of cells within three weeks. These findings suggest that the resistance of HIV-1 infected chimpanzees to progression to AIDS is due to their relative resistance to the systemic effects of HIV-1 on T-cell dysfunction.

Acquired Immunodeficiency Syndrome↗
PubMed1995

In vitro hepatic metabolism of ABT-418 in chimpanzee (Pan troglodytes). A unique pattern of microsomal flavin-containing monooxygenase-dependent stereoselective N'-oxidation.

Metabolism of the cholinergic channel activator [N-methyl-3H]ABT-418 was studied using precision-cut tissue slices and microsomes (+/- cytosol) prepared from a single chimpanzee liver. In both cases, the products of C-oxidation (lactam) and N'-oxidation (cis > trans) were detected. In the presence of chimpanzee liver microsomes and cytosol, which had been characterized with respect to the levels of aldehyde oxidase (N1-methylnicotinamide oxidase), NADPH-dependent flavin-containing monooxygenase (FMO; N, N-dimethylaniline N-oxidase), and various cytochrome P450 (CYP)-dependent monooxygenase activities, ABT-418 lactam and N'-oxide formation was found to be largely dependent on CYP/aldehyde oxidase and FMO, respectively. The rank order of total (trans + cis) FMO-dependent N'-oxidation in liver microsomes was dog > rat > rabbit > chimpanzee > or = cynomolgus monkey > human. It is concluded that the metabolic profile of ABT-418 in the chimpanzee is unique. First, the C-/N'-oxidation ratio in liver slices (0.43) is similar to that of the rat and dog and dissimilar to that of the rat and dog and dissimilar to that of the two other primate species studied; human and cynomolgus monkey (C-/N'-oxidation ratio > or = 9.4). Second, the pattern of ABT-418 N'-oxidation observed with chimpanzee liver microsomes, and liver slices (trans:cis = 1:3), differs from that of rat, rabbit, and dog liver microsomes, rat and human kidney S-9 (trans >> cis), human liver microsomes (trans:cis approximately 1:1), and cynomolgus monkey (trans:cis approximately 2:1) liver microsomes. Lack of stereoselective N'-oxidation by human FMO was confirmed with cDNA-expressed FMO3.

Animals↗
PubMed2005

Initial sequence of the chimpanzee genome and comparison with the human genome.

Here we present a draft genome sequence of the common chimpanzee (Pan troglodytes). Through comparison with the human genome, we have generated a largely complete catalogue of the genetic differences that have accumulated since the human and chimpanzee species diverged from our common ancestor, constituting approximately thirty-five million single-nucleotide changes, five million insertion/deletion events, and various chromosomal rearrangements. We use this catalogue to explore the magnitude and regional variation of mutational forces shaping these two genomes, and the strength of positive and negative selection acting on their genes. In particular, we find that the patterns of evolution in human and chimpanzee protein-coding genes are highly correlated and dominated by the fixation of neutral and slightly deleterious alleles. We also use the chimpanzee genome as an outgroup to investigate human population genetics and identify signatures of selective sweeps in recent human evolution.

Alleles↗
PubMed1999

Chimpanzee thumb muscle cross sections, moment arms and potential torques, and comparisons with humans.

This study investigates the morphological basis of differences between humans and chimpanzees in the kinematical and dynamical parameters of the musculature of the thumb. It is partly intended to test an hypothesis that human thumb muscles can exert significantly greater torques, due to larger muscle cross-sectional areas or to longer tendon moment arms or to both. We focus on the estimation of the potentials of thumb muscles to exert torques about joint axes in a sample of eight chimpanzee cadaver hands. The potential torque of a muscle is estimated by taking the product of a muscle's physiological cross-sectional area (an estimator of force) with its dynamical moment arm (derived from the slope of tendon excursion versus joint angular displacement, obtained during passive movements of cadaver thumb joints). Comparison of our results with similar data obtained for humans at the same Mayo Clinic laboratory shows significant differences between humans and chimpanzees in potential torque of most thumb muscles, those of humans generally exhibiting larger values. The primary reason for the larger torques in humans is that their average moment arms are significantly longer, permitting greater torque for a given muscle size. An additional finding is that chimpanzees and humans differ in the direction of secondary thumb metacarpal movements elicited by contraction of some muscles, as shown by differences in moment arm signs for a given movement in the same muscle. The differences appear to be related to differences in the musculo-skeletal structures of the trapeziometacarpal joint.

Animals↗
PubMed1998

Shadows on a changing landscape: comparing nesting patterns of hominids and chimpanzees since their last common ancestor.

Studying the evolution of nesting behavior within the human-chimpanzee clade is problematic because evidence is sparse and difficult to interpret. Lacking a fossil or archaeological record for proto-chimpanzees, reconstructions of the antecedents of modern chimp nesting patterns can be reconstructed only from careful studies of variation in current chimpanzee and bonobo nesting patterns within the context of spatial and temporal landscape parameters. The ethology of nesting also provides an important frame of reference for reconstructions of early hominid nesting behavior. If the contemporary contrast between human and chimpanzee nesting patterns is seen as an evolutionary dichotomy, then African prehistoric landmarks that mark the origin of this split might include bipedalism and the origins of the hominidae, the first stone tools and the origins of Homo, the developmental and behavioral adaptations of Homo ergaster, shifts in Late Acheulian settlement patterns, and the origins of anatomically modern humans and the Middle Stone Age. The issue of whether Early Stone Age archaeological sites were used for nesting is unresolved because potential markers of such behavior, such as hearths, structures, or bedding, are not unambiguously recognizable in the archaeological record until the Middle Stone Age.

Africa↗
PubMed1999

Subsistence strategies of two "savanna" chimpanzee populations: the stable isotope evidence.

Twenty-two chimpanzee hair samples collected from night nests at two different "savanna" sites were analyzed for carbon and nitrogen stable isotope ratios represented as delta13C and delta15N values. The first at Ugalla, Tanzania is a miombo woodland with grass groundcover and small patches of forest. The second at Ishasha, Democratic Republic of the Congo is a habitat composed of riverine gallery forest, semideciduous thicket forest, wooded grassland, and grassland. Based on comparative data from other primates, Ugalla hair delta13C values suggest that the chimpanzees are feeding primarily in the woodland rather than in forest patches or on grassland foods (grasses or grammivorous fauna). Similar comparisons indicate that the Ishasha chimpanzees are feeding within the forests and not in more open areas. In addition, the Ugalla chimpanzees had delta15N values that indicate extensive ingestion of leguminous flowers, seeds, and/or leaves. The Ishasha samples show a range encompassing three trophic levels. Two samples with the most positive values may indicate a nursing signal or vertebrate-feeding. Three individuals with intermediate values are similar to those in omnivorous nonhuman primate species. The four individuals with the lowest values are very similar to those in herbivorous monkeys. Stable isotope ratios permit time-averaged and habitat-specific dietary comparisons among sites, even without habituation or detailed foraging observations.

Animals↗
PubMed2003

Demography, female life history, and reproductive profiles among the chimpanzees of Mahale.

Demography provides critical data to increase our understanding of the evolution, ecology, and conservation of primate populations. The chimpanzees of the Mahale Mountains National Park, Tanzania, have been studied for more than 34 yr on the basis of individual identification and standardized attendance records. From this long-term study, we derived the following demographic data: The major cause of death was disease (48%), followed by senescence (24%) and within-species aggression (16%). Fifty percent of Mahale chimpanzees died before weaning. The median ages of female life history variables were: first maximal swelling, 10.0 yr (n = 5); emigration, 11.0 yr (n = 11); and first birth, 13.1 yr (n = 5). The median period of adolescent infertility was 2.8 yr (n = 4) when calculated from the age at immigration to that at first birth. Female fecundity was highest between 20 and 35 yr of age, with an annual birth rate of 0.2. Twenty-six females that were observed from a young age (10-13 yr) to death at various ages (15-40 yr) gave birth to an average of 3.9 and weaned an average of 1.4 offspring. Twenty-five females that were observed from middle age (18-33 yr) to death in older age (31-48) gave birth to an average of 2.7 and weaned an average of 2.0 offspring. The post-reproductive lifespan for female chimpanzees was defined as the number of years that passed from the year when the last offspring was born to the year when the female died, minus 5. Twenty-five percent of old females had a post-reproductive lifespan. The interbirth interval after the birth of a son (x = 72 mo) tended to be longer than that after the birth of a daughter (x = 66 mo). The extent of female transfer, which is a rule in chimpanzees, is influenced by the size and composition of the unit group and size of the overall local community.

Age Factors↗
PubMed2002

Genetic diversity of Y-specific STRs in chimpanzees (Pan troglodytes).

Using the primers described for humans, sequences for 11 Y-specific microsatellites (DYS434, DYS435, DYS436, DYS437, DYS438, DYS439, GATA A10, A7.1, A7.2, C4, and H4 [Gusmão et al., in press]), previously described in 10 male chimpanzees (Pan troglodytes), were confirmed in nine additional male chimpanzees. Sequences for nine additional microsatellites (DYS19, DYS385I and II, DYS389I and II, DYS390, DYS391, DYS392, and DYS393) were determined in all 19 male chimpanzees; homology to human Y-Short Tandem Repeat (STRs) was confirmed by sequencing. Good amplification results were not obtained for DYS19 and DYS385I/II. Two amplicons were obtained for DYS389I/II, but in contrast to humans, the larger fragment was not Y-specific. Moreover, no polymorphism was observed for DYS434, DYS435, or GATA A10. Consequently, these eight STRs were eliminated from further analyses, and haplotype and allele frequencies were estimated for the remaining 12 STRs. A high haplotype diversity value was found (1.000 +/- 0.017), demonstrating the usefulness and informative power of these Y-STRs for future studies on chimpanzee population genetics.

Amino Acid Sequence↗
PubMed2004

Mitochondrial DNA genealogy of chimpanzees in the Nimba mountains and Bossou, West Africa.

The chimpanzee populations of the Bossou and Nimba regions in West Africa were genetically surveyed to 1) reveal the genetic relationship between the Bossou and Nimba populations, and 2) elucidate the evolutionary relationship between the Bossou-Nimba and other West African populations. The chimpanzee group at Bossou is characterized by its small population size, no evidence of contact with neighboring populations, and no female immigration. It is believed that most females and adolescent males emigrate from this population. To reveal the genetic signature of these characteristics, we examined the genetic diversity of Bossou and two neighboring populations (Seringbara and Yealé) in the Nimba Mountains by sequencing approximately 605 bp of the mitochondrial DNA (mtDNA) control region. A total of 20 distinct mtDNA variants were observed from 56 sequences of noninvasively collected, anonymous samples. Nucleotide diversity in the Nimba Mountain populations was 0.03-0.04, and did not differ significantly from that in the Bossou population. Very few mitochondrial variants are shared among the sites sampled, which suggests that there is little gene flow involving mtDNA. Nevertheless, no clear population structures were revealed in either population. A comparison with published sequences from West African chimpanzees (Pan troglodytes verus) indicates that the variants observed in the Bossou and Nimba regions are scattered throughout the subspecies, rather than clustered according to geographic region. This suggests that the Bossou-Nimba populations derived only recently from the common ancestral population of the West African chimpanzees, and did not pass through a bottleneck.

Animals↗
PubMed2005

Chimpanzee (Pan troglodytes troglodytes) tool use in the Ngotto Forest, Central African Republic.

Over a 7-month period, stick tools constructed by chimpanzees were collected and measured at the Ngotto Forest site in Central African Republic. The chimpanzees were found to use tools to dip for ants and to probe for honey. The basic descriptions of these tools and the contexts in which they were found are presented. The lengths of two of the tool types were compared with the use of a t-test for independent groups. It was found that the lengths of the tools differed significantly depending upon their function. The location and habitat type of each tool site were plotted on a map. The tool types were distributed throughout the southern part of the study area, and with one exception all tool sites were found in the same type of habitat. Two tool sites with two other types of tools (honey hammer/club and ant club) were found. The tool types at Ngotto are compared with those found at other chimpanzee field sites, and the implications for diversity in chimpanzee material culture are discussed.

Animals↗
PubMed2005

Tool use in insect foraging by the chimpanzees of Ngogo, Kibale National Park, Uganda.

Chimpanzee tool use for resource acquisition has been reported at numerous research sites. The chimpanzees of the Kibale Forest, western Uganda, have not previously been observed to use tools in foraging for insects. Here I report the first observation of tool use by the chimpanzees of the Ngogo community of Kibale National Park, Uganda, in insect foraging. Three adult females, one adolescent male, and one juvenile male were observed making and using tools to probe into a fallen dead tree to collect insect and wood pieces. I discuss the importance of this observation, and the behavioral similarities with chimpanzees from other sites.

Animals↗
PubMed2005

Subspecies composition and founder contribution of the captive U.S. chimpanzee (Pan troglodytes) population.

Chimpanzees are presently classified into three subspecies: Pan troglodytes verus from west Africa, P.t. troglodytes from central Africa, and P.t. schweinfurthii from east Africa. A fourth subspecies (P.t. vellerosus), from Cameroon and northern Nigeria, has been proposed. These taxonomic designations are based on geographical origins and are reflected in sequence variation in the first hypervariable region (HVR-I) of the mtDNA D-loop. Although advances have been made in our understanding of chimpanzee phylogenetics, little has been known regarding the subspecies composition of captive chimpanzees. We sequenced part of the mtDNA HVR-I region in 218 African-born population founders and performed a phylogenetic analysis with previously characterized African sequences of known provenance to infer subspecies affiliations. Most founders were P.t. verus (95.0%), distantly followed by the troglodytes schweinfurthii clade (4.6%), and a single P.t. vellerosus (0.4%). Pedigree-based estimates of genomic representation in the descendant population revealed that troglodytes schweinfurthii founder representation was reduced in captivity, vellerosus representation increased due to prolific breeding by a single male, and reproductive variance resulted in uneven representation among male P.t.verus founders. No increase in mortality was evident from between-subspecies interbreeding, indicating a lack of outbreeding depression. Knowledge of subspecies and their genomic representation can form the basis for phylogenetically informed genetic management of extant chimpanzees to preserve rare genetic variation for research, conservation, or possible future breeding.

Africa↗