Radioimmunoassay of somatomedin-C in the baboon (Papio cynocephalus): A comparison of multiple techniques of measurement

This study was undertaken to assess the nature of somatomedin-C (SM-C) in baboon (Papio cynocephalus) blood and to compare various methods for estimating SM-C concentrations. Parallel dose-response curves were obtained with normal baboon serum, normal human serum, and purified SM-C. Recovery of purified SM-C added to baboon serum over a wide dosage range (n = 17) was 111 ± 12%, with slightly better recovery at higher potencies. Chromatography of normal baboon serum on Sephadex G-200 at neutral pH produced a profile similar to that observed in the human, as did samples chromatographed on Sephadex G-50 in acid. Although the SM-C content in acid chromatographed plasma was approximately 2.5 times higher than in native unprocessed plasma, there was excellent correlation between the values (r = 0.9143, p < 0.0001). The SM-C in baboon plasma which had been preincubated with glycine HCl was approximately twice that of unprocessed plasma, but the correlation between the two methods was excellent (r = 0.9593, p < 0.0001). The correlation between values obtained after simple acid-ethanol extraction and those observed in unextracted plasma were also significant (r = 0.7689, p < 0.0001). Following a series of four injections of human growth hormone (hGH) to a normal baboon, plasma SM-C rose approximately sevenfold above the initial concentration and returned to basal levels five days after the final injection. These studies show that although the radioimmunoassay (RIA) for SM-C in unprocessed baboon plasma does not measure all of the SM-C present, it provides a reliable index of the total SM-C concentration and reflects GH status in the baboon.     

Systematic reconsideration and a revision of the nomenclature of Kenya baboons

Two populations of baboons in Kenya, often given different specific names, Papio doguera and Papio cynocephalus, were the subject of this investigation. We conducted a field study to determine if these two populations are the same or two different species. We located a zone of contact between the two putative species in the area of Simba Springs and Ithumba Hill. The population in this area was found to represent intergradation on the basis of field observations and detailed metric observations of the morphology. The morphology of this population appears to be intermediate between that of the two populations: the olive baboon, labeled Papio doguera, and the yellow baboon, labeled Papio cynocephalus. We confirmed the findings by statistical analyses of osteometric data. Since the specific separation of the two taxa studied in this investigation is invalid, both are placed in the prior nomen, Papio cynocephalus (Linnaeus, 1766) separating them on the subspecific level, P. c. doguera and P. c. cynocephalus.     

Detection of serum antibodies in Ethiopian baboons that cross-react with SIV,HTLV-I,and type D retroviral antigens

Baboons (Papio cynocephalus) imported from Ethiopia were screened for antibodies to various primate retroviruses by immunoblotting. Antibodies that cross-reacted with SIV/Mne or with type D viral antigens were detected in approximately one-third of these animals. In addition, 20% of these baboons had antibodies that cross-reacted with HTLV-I viral antigens. These data suggest that wild-caught baboons are infected with retroviruses only partially related to known primate viral isolates.     

The A-B-O blood groups of baboons

A new series of 188 baboons, Papio papio, Senegal, have been tested for the human type A-B-O groups with the following results: 2 group O, 27 group A, 93 group B and 66 group AB. This distribution fits the Hardy-Weinberg formula perfectly, using the allele frequencies O = 10.3%, A = 29.0%, and B = 60.8%. Up to date, five series of baboons comprising a total of 684 animals have been tested for their A-B-O groups. On these 684 baboons, from three different species, only three belonged to group O. Nevertheless, there is convincing indirect evidence that in most of the baboon species tested so far the frequency of gene O is about 10%. There are significant differences in the distribution of the blood groups in the various baboon species, comparable to the differences in racial distribution of the A-B-O blood groups in man, e.g., the frequency of gene A ranges from 18.2% in Papio ursinus, South Africa, to 48.3% in Papio cynocephalus. The usefulness of the methods of population genetics, viz, allele frequency analysis, for studies of blood groups in primates is demonstrated. The differences and similarities between the A-B-O blood groups in man and baboons are discussed.     

Fecal steroid analysis of ovarian cycles in free-ranging baboons

This paper reports field and laboratory tests of serial sampling, solid phase extraction, and microradioimmunoassay methods for the collection, preservation, and analysis of fecal steroids. The field study was conducted in a troop of 87 yellow baboons (Papio cynocephalus) in the Tana River Primate Reserve, Kenya. Serial samples of four focal females and opportunistic sampling of 18 additional females over 22 days of sampling yielded a total of 62 samples, X = 3.1 ± 0.4/day, demonstrating the feasibility of regular field collection and extraction. Estradiol and progesterone concentrations in the field-extracted samples exhibited high recovery and statistically significant correlations (P < 0.05) with concentrations in the lab-extracted samples, suggesting that solid phase extraction could provide a useful alternative to freezing in sites where electricity or liquid nitrogen is not available. Tests of microradioimmunoassays demonstrated that these assays were sensitive, accurate, and precise when applied to the assay of fecal extracts, providing estimates of ovarian steroids that varied significantly with reproductive state. The demonstration that testosterone could be accurately and reliably assayed in fecal extracts suggests that these techniques also could be applied to the study of male reproductive function. Parallels between fecal profiles of cycling and pregnant baboons with patterns reported for serum steroids in baboons suggest that fecal steroids might be useful in distinguishing amenorrhea from early pregnancy in free-ranging baboons as well as in species lacking external indices of reproductive state. © 1995 Wiley-Liss, Inc.     

Genetic differentiation between baboon subspecies: Relevance for biomedical research

The use of common names which may encompass a number of subspecies or species is pervasive in the biomedical literature. Failure to identify the complete taxonomic classification of research subjects presents a source of error for scientists attempting to evaluate results or to repeat experiments. This paper examines the problem in a common animal model, the baboon. Analyses of the genetic distances among five baboon subspecies (Papio hamadryas anubis, P.h. cynocephalus, P.h. papio, P.h. ursinus, and P.h. hamadryas) based on blood marker information from nine polymorphic protein loci (ADA, APRT, C3, CA1, CA2, GPI, MPI, PEPB, and PGD) available for baboons resident at the Southwest Foundation for Biomedical Research are presented. Statistical tests on the distances showed that significant genetic differences exist among the subspecies. A comparison of P.h. anubis and P.h. cynocephalus revealed that these two subspecies also differ significantly for biomedically relevant lipoprotein cholesterol levels, as can be predicted from the genetic distances. The results emphasize the pitfalls of using different types of baboons interchangeably in experimental protocols.     

Brief report: Body water estimates in normally grown baboon neonates

Water contents of various body water compartments were estimated within nine hours of birth in 11 preterm and eight term baboon (Papio cynocephalus neonates. Estimated water contents of all body compartments (in ml) increased linearly with birthweight (r = 0.52 to 0.90, P ≦ 0.007) and with gestational age (r = 0.46–0.94, P ≤ 0.05). When body water estimates were expressed in proportion to bodyweight (in ml/kg), preterm neonates had significantly larger mean antipyrine space and intracellular water than their term peers. Mean corrected bromide space, interstitial water, plasma volume, blood volume, and red cell volume were similar in preterm and term neonates. Although there are minor differences in body water contents and distribution between baboon and human neonates, baboon data are sufficiently similar to human data to justify using the baboon fetus and neonate as a model for investigations of human development.     

A cytogenetic survey of 110 baboons (Papio cynocephalus)

A cytogenetic investigation of 110 adult baboons (Papio cynocephalus) captured in Kenya and sacrificed at the Institut Pasteur, Paris, showed the absence of anomalies, numerical or structural bearing on nonheterochromatic material; a polymorphism of the AgNOR-positive secondary constriction of chromosome 5 in 12% of the animals; a polymorphism of a secondary constriction of chromosome 7 in 2% of the animals; a fragile site of chromosome 6 in one animal. We believe that our data show that cytogenetic observations in present day primates probably reflect their chromosomal evolution.     

Carbonic anhydrase heterozygosity and FST distributions in Kenyan baboon troops

An analysis of the distribution of carbonic anhydrase alleles in troops of olive baboons, Papio cynocephalus, is reported. In an earlier study (Olivier, T. J., J. Buettner-Janusch and V. Buettner-Janusch, 1974, Am. J. Phys. Anthrop., 41: 175–190) the authors found a significant excess of heterozygotes with a large amount of intertroop differentiation at the CA II locus. If balancing selection is acting on the CA II locus and maintaining an excess of heterozygotes, then the degree of local differentiation observed at this locus is unexpected. In this study the analyses of the CA I and CA II data are extended and some idiosyncratic features of baboon population structure are considered. Non-idealized forms of behavior, such as adult male migration and other age-specific and sex-specific behaviors, may affect observed patterns of gene frequency distributions. The analysis reveals that the excess of heterozygotes at the CA II locus is localized in the females only and that the males are highly differentiated among the troops. These findings suggest that a female-limited heterozygous advantage exists at the CA II locus in this baboon population. A computer simulation model, RAMBLE, further suggests that recurrent male migration between troops may explain the intertroop microdifferentiation found in primate populations.     

Demography of Amboseli baboons, 1963–1983

Repeated censuses of a population of yellow baboons (Papio cynocephalus) in Amboseli National Park, Kenya, revealed a decrease from over 2,500 animals in 1963–1964 to 123 individuals in 1979, or from a density of about 73 to 1.8 baboons per km² over a 15-year period. Median group size decreased from 43 in 1964 to 27 in 1979. The largest and smallest groups declined the most; groups near the median have maintained fairly stable size and age distributions. The population seemed to have stabilized by 1983 at approximately 150 animals in six groups (median group size 28; density 2.2/km²). Although baboon population and group size appeared to be stable during 1963–1964, the age distribution and demographic parameters (age-specific mortality and natality for one social group) during that year indicate that the population decline had already started. The rate of population decline was greatest in the 1964–1969 period and remained appreciable during the next 5 years. The decline of the baboon population was paralleled by that of other Amboseli savannah woodland mammalian species and took place during a period of very high mortality of fever trees (Acacia xanthophloea) and extensive invasion of the area by halophytes, a transition brought on by rising ground water and consequent elevation of the soil salinity zone. In this and several other primate populations, mortality of infants and juveniles appears to be the demographic variable most sensitive to environmental change.     

Correlates of agonistic and competitive interactions in pregnant baboons

Maternal condition during pregnancy is known to influence fetal viability. Recently, primatologists have suggested that certain characteristics of the fetus may influence maternal condition as well. For example, among captive pigtailed macaques (Macaca nemestrina) mothers of female infants may be at greater risk of injury during their pregnancies than mothers of male infants. Analysis of the rates of aggression, submission, competition, and wounding among free-ranging pregnant baboons (Papio cynocephalus) in Amboseli National Park generally fail to support these findings, but several other factors such as maternal dominance rank, environmental conditions during pregnancy, maternal parity, and fetal age correlate with aggression, submission, competition, and injuries sustained by pregnant female baboons.     

The ecology of conception and pregnancy failure in wild baboons

Environmental conditions are a key factor mediating reproductivesuccess or failure. Consequently, many mammalian taxa have breedingseasons that coordinate critical reproductive stages with optimalenvironmental conditions. However, in contrast with most mammals,baboons (Papio cynocephalus) of Kenya reproduce throughout theyear. Here we depart from the typical approach of evaluatingseasonal effects on reproduction and engage in a more fine-grainedanalysis of the actual ecological conditions leading up to reproductionfor females. Our aim was to determine how environmental conditions,in combination with social and demographic factors, might mediatebaboon reproduction. The data set includes all female reproductivecycles from multiple baboon groups in the Amboseli basin between1976 and 2004. Results indicate that after periods of droughtor extreme heat, females were significantly less likely to cyclethan expected. If females did cycle after these conditions,they were less likely to conceive; and if they did conceiveafter drought (heat effects were nonsignificant), they wereless likely to have a successful pregnancy. Age also significantlypredicted conceptive failure; conceptive probability was lowestamong the youngest and oldest cycling females. There was alsoa trend for high ambient temperatures to contribute to fetalloss during the first trimester but not other trimesters. Finally,group size and drought conditions interacted in their effectson the probability of conception. Although females in all groupshad equal conception probabilities during optimal conditions,females in large groups were less likely than those in smallgroups to conceive during periods of drought. These resultsindicate that in a highly variable environment, baboon reproductivesuccess is mediated by the interaction between proximate ecologicalconditions and individual demographic factors.     

Fatal intragroup kidnapping in yellow baboons

The fatal kidnapping of a 5-day-old baboon (Papio cynocephalus) in Amboseli National Park, Kenya, is described. Although pulling and rough handling of primate infants by nonmothers are frequently observed, records of fatal intragroup kidnappings are rare. In the instance described here, the mother, a healthy, primiparous female, did not retrieve the infant from the kidnapper, a higher-ranking juvenile female of the same group, until he died 3 days later, presumably from starvation or dehydration. This incident is compared with other fatal intragroup kidnappings in nonhuman primates and related to adaptive interpretations.     

Dental eruption schedules of wild and captive baboons

Dental eruption schedules previously used to age wild baboons have in the past derived from studies of captive animals housed under standard conditions and fed standard laboratory diets. This paper reports for the first time eruption schedules derived from wild baboons, the yellow baboons (Papio hamadryas cynocephalus) of Mikumi National Park, Tanzania, and compares these schedules with those of other baboon subspecies inhabiting both similar and dissimilar environments. Eighteen males and twelve females from the Viramba groups, ranging in age from 21 to 103 months, were trapped, and dental impressions and notes were made of the state of eruption of each tooth. Eruption of all teeth were delayed at Mikumi relative to the baboon standards derived from the captive animals at the Southwest Foundation for Biomedical Research, San Antonio, Texas. Teeth of the canine-premolar 3 complex and third molars were most delayed, erupting up to a year and a half later than their counterparts from captive animals. Comparison with data on hamadryas baboons from Erer-Gota in Ethiopia revealed that both the hamadryas and yellow subspecies of baboons, with different genetic backgrounds and living under markedly different environmental conditions, followed the same schedule. This constancy of developmental schedules suggests that these Mikumi data may reasonably be used as standards for other wild baboon populations and that acceleration of dental maturation, as well us maturation of other somatic systems in captivity, is another manifestation of the short-term adaptive plasticity of the baboon species as a whole.     

Social relationships of mountain baboons: Leadership and affiliation in a non-female-bonded monkey

Instead of close and differentiated relationship among adult females, the accepted norm for savanna baboons, groups of Drakensberg mountain baboons (Papio ursinus) showed strong affiliation of females towards a single male. The same male was usually the decision-making animal in controlling group movements. Lactating or pregnant females focused their grooming on this “leader” male, producing a radially patterned sociogram, as in the desert baboon (P. hamadryas); the leader male supported young animals in the group against aggression and protected them against external threats. Unlike typical savanna baboons, these mountain baboons rarely displayed approach-retreat or triadic interactions, and entirely lacked coalitions among adult females. Both groups studied were reproductively one-male; male-female relationships in one were like those in a unit of hamadryas male at his peak, while the other group resembled the unit of an old hamadryas male, who still led the group, with a male follower starting to build up a new unit and already monoplizing mating. In their mountain environment, where the low population density suggests conditions as harsh for baboons as in deserts, adults in these groups kept unusually large distances apart during ranging; kin tended to range apart, and spacing of adults was greatest at the end of the dry, winter season. These facts support the hypothesis that sparse food is responsible for convergence with hamadryas social organization. It is suggested that all baboons, though matrilocal, are better categorized as “cross-sex-bonded” than “female bonded”.     

Inbreeding,heterozygosity, and lymphoma risk among the baboons (Papio hamadryas) of Sukhumi,USSR

This paper describes the spread of lymphoma through a baboon (Papio hamadryas) colony in the Institute of Experimental Pathology and Therapy at Sukhumi, USSR. In the late 1960s, Soviet scientists inoculated 12 baboons with cells from hospitalized human leukemia patients, causing the death of a total of 135 animals between 1967 and 1978. The death rate from lymphoma averages almost 12 baboons per year in the Sukhumi colony. Genetic investigations of these baboons revealed the following: 1) Six blood protein markers out of 16 systems (38%) tested were polymorphic; 2) the average inbreeding coefficient for the entire colony (N = 1,226) was 0.027 (exclusion of baboons with F values equal to 0.0 raised the mean inbreeding coefficient to 0.096); 3) no relationship between inbreeding and risk of lymphoma was noted; and 4) there was an apparent association between both PGM loci and the incidence of lymphoma at the 0.005 levels of significance. This association was further supported by the significantly lower incidence of PGM2 (2-1) genotype in baboons with high anti-VCA-HVP titers.     

The Ap-Bp blood groups of baboons

Four isoimmunized baboons each produced isoantibodies defining a number of blood factors of baboon blood of which two, A^p and B^p, have been most intensively studied. The two blood factors determine the A^P-B^P blood group system which, judging from its serological behavior, may be the baboon analogue of the human M-N system and the chimpanzee V-A-B system. Tests for A^P-B^P types of 592 baboons showed striking differences in the distributions of the four types among the four sub-species, Papio cynocephalus, Papio anubis, Papio ursinus (South Africa) and Papio papio (Senegal). The baboon A^P-B^P types could also be demonstrated by tests on the red cells of geladas (Theropithecus gelada). If one assumes inheritance by multiple allelic genes, then the existence of only a single gene O^p need be invoked for Papio ursinus, three alleles O^p, A^p and B^p for Papio cynocephalus and Papio anubis, but four alleles for Papio papio including an allele, very frequent in that subspecies, which determines an agglutinogen having both blood factors A^p and B^p.     

Genomewide ancestry and divergence patterns from low‐coverage sequencing data reveal a complex history of admixture in wild baboons

Naturally occurring admixture has now been documented in every major primate lineage, suggesting its key role in primate evolutionary history. Active primate hybrid zones can provide valuable insight into this process. Here, we investigate the history of admixture in one of the best‐studied natural primate hybrid zones, between yellow baboons (Papio cynocephalus) and anubis baboons (Papio anubis) in the Amboseli ecosystem of Kenya. We generated a new genome assembly for yellow baboon and low‐coverage genomewide resequencing data from yellow baboons, anubis baboons and known hybrids (n = 44). Using a novel composite likelihood method for estimating local ancestry from low‐coverage data, we found high levels of genetic diversity and genetic differentiation between the parent taxa, and excellent agreement between genome‐scale ancestry estimates and a priori pedigree, life history and morphology‐based estimates (r² = 0.899). However, even putatively unadmixed Amboseli yellow individuals carried a substantial proportion of anubis ancestry, presumably due to historical admixture. Further, the distribution of shared vs. fixed differences between a putatively unadmixed Amboseli yellow baboon and an unadmixed anubis baboon, both sequenced at high coverage, is inconsistent with simple isolation–migration or equilibrium migration models. Our findings suggest a complex process of intermittent contact that has occurred multiple times in baboon evolutionary history, despite no obvious fitness costs to hybrids or major geographic or behavioural barriers. In combination with the extensive phenotypic data available for baboon hybrids, our results provide valuable context for understanding the history of admixture in primates, including in our own lineage.     

Implication of Papio anubis in the transmission of intestinal schistosomiasis in three new foci in Kime area, Ethiopia

Epidemiological studies were conducted in the Lake Langano area in the Rift Valley of Ethiopia to determine the occurrence of schistosomiasis and assess factors involved in its transmission. Microscopic examination of faecal specimens from free ranging Papio anubis (anubis baboon) troops from Bishan Gari and Burka Dita forest reserves revealed Schistosoma mansoni eggs with a prevalence of 12.1% (11/91) and 26.2%(34/130), respectively. The eggs were viable as confirmed by miracidial hatching and infectivity tests. Out of the total 12 communities (three schools, five villages and one herdsmen community) surveyed for schistosomiasis around Lake Langano, individuals excreting S. mansoni eggs were found in nine communities with prevalence of infection ranging from 1.4 to 43%. The intensity of infection ranged from 24 EPG (eggs per gram of faeces) to 243 EPG. Excretion of viable eggs by the baboons indicate that they play a role in maintenance of S. mansoni infection in the locality. The detection of S. mansoni eggs in young children, collection of cercarial-infected Biomphalaria pfeifferi in water bodies, and establishment of S. mansoni infection in lab-bred mice have confirmed establishment of transmission foci in Kime area, south-east of Lake Langano. However, the lake itself does not seem to support transmission of schistosomiasis since no snails were found along the shore of the Lake. Further investigations are indicated to fully elucidate the role baboons play in the epidemiology of schistosomiasis in the Rift Valley of Ethiopia. The risk of introduction of water-based development projects in these new endemic foci in relation to S. mansoni infection in the baboons is discussed.     

Fetal hemoglobin in newborn baboons, Papio cynocephalus

Hemoglobins from a newborn baboon, Papio cynocephalus, and from a 15-day-old baboon of the same species were examined for electrophoretic properties of polypeptide chains and were tested for alkali resistance. Hemoglobin of newborn P. cynocephalus appears to be analogous to human fetal hemoglobin. Hemoglobin of newborn P. cynocephalus is composed of α-like and γ-like chains and hemoglobin of adult P. cynocephalus is composed of α-like and β-like chains.