Brief report: Crocodile predation on a crab-eating macaque in Borneo

An immature crab-eating macaque (Macaca fascicularis), which was sitting on the river bank near the Orangutan Research and Conservation Project base camp in the Tanjung Puting Reserve, Kalimantan Tengah, Indonesia, was seized by a crocodile which rapidly emerged from the water and then resubmerged with the monkey in its jaws. As crocodile populations are in a decline throughout Borneo, crocodile predation on crab-eating macaques was probably more frequent in the past. This predation may have influenced development of some behaviors with an antipredator function in M. fascicularis.     

Determining genetic background in captive stocks of cynomolgus macaques (Macaca fascicularis)

Background As in other model organisms, genetic background in the non‐human primates Macaca mulatta and Macaca fascicularis is an experimental variable that affects the response of other study variables. Genetic background in model organisms is manipulated by breeding schemes but is generally pre‐determined by the source population used to found captive stocks. In M. fascicularis three such sources have been distinguished, however, these are not routinely taken into consideration when designing research. Methods We exemplify a mitochondrial DNA (mtDNA)‐based strategy to trace the maternal geographic origins of M. fascicularis animals of unspecified origins. Results Macaca fascicularis of unspecified origins kept at primate research centers carry mtDNA haplotypes representing all three major genetic subdivisions. Conclusions We suggest that the genetic background of study animals could be better specified in the future using an mtDNA‐based approach, which would enable informed selection of study animals and help reduce variation within and among studies.     

Y-Chromosome and Mitochondrial Markers in Macaca fascicularis Indicate Introgression with Indochinese M. mulatta and a Biogeographic Barrier in the Isthmus of Kra

This is the first report of Y-chromosome introgression between primate species. We sequenced 3.1 Kb of Y-chromosome DNA and 1.5 Kb of mtDNA for 27 macaques of Fooden's (Folia Primatol. [1976] 25: 225–236) fascicularis species group and 5 outgroup taxa (Macaca sylvanus, Papio hamadryas, Theropithecus gelada, Allenopithecus nigroviridis, and Cercopithecus mona). Phylogenies constructed separately for the paternal and maternal data sets show a Y-chromosome paraphyly among lineages of Macacafascicularis, but a mitochondrial monophyly for the same individuals. The Y-chromosome topology depicts Indochinese Macaca fascicularis haplotypes joining with those of M. mulatta, followed by M. cyclopis and M. fuscata, before clustering with a clade of lineages of M. fascicularis from peninsular Malaysia, Indonesia, and the Philippines. These contrasting patterns of mitochondrial and Y-chromosome DNA, evaluated in the context of the evolutionary consequences of macaque sex-biased dispersal, present strong evidence for contemporary hybridization between Macaca fascicularis and M. mulatta in Indochina and a biogeographic barrier in the Isthmus of Kra.     

Polyspecific groups of macaques on the kowloon peninsula,new territories,Hong Kong

Three polyspecific groups of free-ranging macaques were observed in July and August of 1980 and 1981 in the forests of the New Territories of mainland Hong Kong. Two groups were composed of rhesus monkeys (Macaca mulatta) and long-tailed or crab-eating monkeys (M. fascicularis), and one group was composed of both the former plus Japanese macaques (M. fuscata). All three groups contained hybrids between M. mulatta and M. fascicularis. This combination of species within the same social group is an unusual circumstance in natural habitats, and it offers a unique opportunity for field studies in primate ecology and behavior.     

Population studies of Malaysian primates

Systematic field studies on the abundance of primates were made in five different types of forest in West Malaysia in 1970. Primate groups of 7 species were seen on 97 occasions during 527 hours of field observations. Secondary forests had the greatest primate density of any of the natural forest habitats surveyed. Estimated primate group densities varied from less than 4 groups per square mile to 40, with an average of 7.2 groups per square mile. The most abundant species was the banded leaf monkey (Presbytis melalophus) with 2.95 groups per square mile, followed by the long-tailed macaque (Macaca fascicularis) with 1.54 groups. Primary forests had a lower density which varied from less than 2 groups per square mile to 15, and averaged 5.9.P. melalophus was again the most abundant species with an average of 2.22 groups per square mile, followed by gibbons (Hylobates lar) and siamangs (H. syndactylus) each with 1.11.M. fascicularis averaged only 0.37 groups per square mile in primary forests. Primates were unexpectedly rare in mangrove forests and rubber plantations. Twenty-four primate groups were found in urban forests and parks. Twenty of these groups wereM. fascicularis, 3 were silver leaf monkeys (P. cristatus) and 1 was the dusky leaf monkey (P. obscurus). In urban areas,M. fascicularis groups varied from 7 to 44 individuals per group, with an average of 24. A great need exists for increased scientific and conservation attention for the primate populations of Malaysia.Contribution from the U.S.A. Medical Research Unit, Institute for Medical Research, Kuala Lumpur, Malaysia.     

Copulatory behavior in relation to anatomical characteristics of three macaques

Anatomy of copulatory organs and patterns of copulatory behavior were studied in three species of Macaca. The copulatory behavior of the rhesus monkey (M. mulatta) and crab-eating macaque (M. fascicularis) were similar. Mounting time was longer in stump-tailed macaque (M. arctoides) (48 seconds) than in the rhesus monkey or crab-eating macaque (8.5 seconds). Species differences were correlated with anatomical differences in the female and male reproductive organs. In the stump-tailed macaque the male has a relatively long penis, and the female has an elaborate vestibular colliculus in the vestibule. Both rhesus and crab-eating macaques have a short penis, and the female has no vestibular colliculus. Under scanning electron microscope, cone-like projections (3–4 mm) were observed on the surface of the glans and corpus penis of M. arctoides. In M. fascicularis shorter projections (0.05–0.1 mm) were observed on the glans penis but not the corpus penis.     

Hemoglobin polymorphism in macaques with reference to the evolution ofMacaca fascicularis andMacaca mulatta

Blood samples were collected fromMacaca fascicularis andMacaca mulatta living in indoor breeding groups and investigated electrophoretically. Hemoglobin polymorphism was observed in both species. Isoelectric focusing was performed on urea denaturated samples to test the hypothesis of a site duplication at theα-chain locus inM. fascicularis (Barnicot et al., 1970). The results of our investigations do not support the above mentioned hypothesis. Only one locus coding theα-chain was detected, and this is under the control of two alleles. Evolutionary events at the molecular level are discussed, as well asWheatley's hypothesis (1980) that malaria was an important force behind divergence in both species. InM. fascicularis hemoglobin variants might be similarily connected with malaria resistance as in man. We suggest that this was not an important process behind speciation in macaques.     

A Flexible Restraint Chair for the Cynomolgus Monkey (Macaca fascicularis)1

We have found that commercial restraint chairs suitable for the rhesus monkey (Macaca mulatta) cause severe physical distress to many cynomolgus monkeys (Macaca fascicularis). A new restraint chair has therefore been designed specifically for the cynomolgus. The key features of the chair are an angled neck piece, a large opening to provide free movement for the tail, a soft waist restraint, and a level surface for both the heels and ischial pads. This new chair is not only suitable for the cynomolgus monkey but may also be more comfortable for the rhesus monkey than standard commercial chairs.     

On the directional orientation of female presents inMacaca fascicularis

The directional orientation of female presents in a captive group of long-tailed macaques (Macaca fascicularis) is markedly dependent upon the sex of the potential recipient. Females present in the ‘standard’ mode significantly more often than in the ‘sideways’ mode to males, with the opposite pattern prevailing to other females.     

Polymorphism in the mitochondrial DNA of cynomolgus monkeys

Variations in the mitochondrial DNA of a total of 150 cynomolgus monkeys (Macaca fascicularis) from Indonesia, the Philippines, and Malaysia were studied using a restriction endonuclease, EcoRI. Three distinct patterns were detected and they were denoted as morph 1, 2, and 3. The Malaysian population proved to be significantly different from the remaining two populations in the distributions of the three EcoRI morphs.     

Lipofuscin in the corpus luteum of macaque ovaries

The present study examined the histochemistry of pigments in the corpus luteum of the ovaries of cynomolgus monkeys (Macaca fascicularis), Japanese monkeys (Macaca fuscata), and rhesus monkeys (Macaca mulatta). Yellowish brown pigments were found in the regressing corpus luteum cells. Histochemical studies revealed that these pigments consisted of lipofuscin, the so-called age pigment. The findings obtained suggest that accumulation of lipofuscin might be related to cellular aging of the corpus luteum.     

Genetic polymorphism of alpha-1-antitrypsin in macaque species

Thirty-two phenotypes of alpha-1-antitrypsin (al-AT) controlled by 18 codominant alleles of PI_mac locus were identified by isoelectric focusing in 1.121 macaques of nine species. In terms of al-AT polymorphism macaque species vary markedly from nearly monomorphic (Macaca mulatta, M. arctoides) to highly polymorphic (M. nemestrina, M. fascicularis). Only 4 of 18 PI_mac alleles are common for two or more macaque species, the rest of the alleles are species-specific.     

Blood groups of bonnet macaques (Macaca radiata), with a brief introduction to seroprimatology

The human-type A-B-O blood groups of 52 bonnet macaques (Macaca radiata) were determined. Application of method of population genetics indicated the gene frequences to be O = 0.173, A = 0.480 and B = 0.347. Cross testing of sera and red cells of the bonnet macaques revealed two blood-type-specific isoagglutinins, one of them strong enough for use as a blood typing reagent. No blood group polymorphism was revealed by testing bonnet macaque red cells with isoantisera produced in rhesus monkeys (M. mulatta) and in crab-eating macaques (M. fascicularis). The rhesus and crab-eating macaque isoantisera reacted either with all or with none of the bonnet macaque red cells tested.     

Trypanosoma cruzi in non-human primates with a history of stillbirths: a retrospective study (Papio hamadryas spp.) and case report (Macaca fascicularis)

Background Congenital transmission of Trypanosoma cruzi has been described in humans and experimental work has been conducted with mice, but not with non‐human primates (NHPs). Methods We conducted a retrospective study of female baboons (Papio hamadryas spp.) naturally seropositive or seronegative for T. cruzi with history of fetal loss, and we report a stillbirth in a cynomolgus macaque (Macaca fascicularis) with placental T. cruzi amastigotes. Results There were no differences in menstrual cycle parameters and the number of fetal losses between seropositive and seronegative baboons with history of fetal loss. The amount of parasite DNA detected using quantitative polymerase chain reaction (Q‐PCR) in M. fascicularis placenta was within the range detected in infected baboon tissues. Conclusions There is no evidence that chronic maternal T. cruzi infection causes fetal loss in baboons. Q‐PCR is a useful diagnostic tool to study archived NHP placentas.     

Ancient genome‐wide admixture extends beyond the current hybrid zone between Macaca fascicularis and M. mulatta

Macaca fascicularis and Macaca mulatta are two of the most commonly used laboratory macaques, yet their genetic differences at a genome‐wide level remain unclear. We analysed the multilocus DNA sequence data of 54 autosomal loci obtained from M. fascicularis samples from three different geographic origins and M. mulatta samples of Burmese origin. M. fascicularis shows high nucleotide diversity, four to five times higher than humans, and a strong geographic population structure between Indonesian‐Malaysian and Philippine macaques. The pattern of divergence and polymorphism between M. fascicularis and M. mulatta shows a footprint of genetic exchange not only within their current hybrid zone but also across a wider range for more than 1 million years. However, genetic admixture may not be a random event in the genome. Whereas randomly selected genic and intergenic regions have the same evolutionary dynamics between the species, some cytochrome oxidase P450 (CYP) genes (major chemical metabolizing genes and potential target genes for local adaptation) have a significantly larger species divergence than other genes. By surveying CYP3A5 gene sequences of more than a hundred macaques, we identified three nonsynonymous single nucleotide polymorphisms that were highly differentiated between the macaques. The mosaic pattern of species divergence in the genomes may be a consequence of genetic differentiation under ecological adaptation and may be a salient feature in the genomes of nascent species under parapatry.     

Circadian variations in serum thyroid hormones inMacaca fascicularis

Serum triiodothyronine (T₃) and thyroxine (T₄) concentrations inMacaca fascicularis were determined at 4-hr interval for 24 hr using commercial radioimmunoassay kits. It was found that the highest concentrations of T₃ and T₄ in the animals were in the serum sample taken at 10:00. The lowest values of T₃ and T₄ were found in the blood sampled at 02:00 and 22:00, respectively.     

Preliminary report on yellow long-tailed macaques (Macaca fascicularis) at Kosumpee Forest Park, Thailand

We conducted a census on long-tailed macaques (Macaca fascicularis) at Kosumpee Forest Park, Thailand, and found 15 individuals of yellow pelage color out of a total of 287 individuals. There were three troops, designated A, B and C, but the yellow macaques were found only in B and C troops. The frequency of yellow macaques was 5.2% in the total population and 4.2 and 9.9% in B and C troops, respectively. These frequencies are much higher than those in rhesus macaques (M. mulatta) reared at Cayo Santiago (0.52%). They are, however, lower than those of 10 years ago.     

Analysis of the expressed heavy chain variable-region genes of Macaca fascicularis and isolation of monoclonal antibodies specific for the Ebola virus' soluble glycoprotein

The cynomolgus macaque, Macaca fascicularis, is frequently used in immunological and other biomedical research as a model for man; understanding it's antibody repertoire is, therefore, of fundamental interest. The expressed variable-region gene repertoire of a single M. fascicularis, which was immune to the Ebola virus, was studied. Using 5′ rapid amplification of cDNA ends with immunoglobulin (Ig)G-specific primers, we obtained 30 clones encoding full-length variable, diversity, and joining domains. Similar to the human V_H repertoire, the M. fascicularis repertoire utilized numerous immunoglobulin heavy variable (IGHV) gene fragments, with the V_H3 (41%), V_H4 (39%), and V_H1 (14%) subgroups used more frequently than the V_H5 (3.9%) or V_H7 (1.7%) subgroups. Diverse immunoglobulin heavy joining (IGHJ) fragments also appeared to be utilized, including a putative homolog of JH5β gene segment identified in the related species Macaca mulatta, Rhesus macaque, but not in humans. Although the diverse V region genes in the IgG antibody repertoire of M. fascicularis had likely undergone somatic hypermutations (SHMs), they nevertheless showed high nucleotide identity with the corresponding human germline genes, 80–89% for IGHV and 72–92% for IGHJ. M. fascicularis and human V_H genes were also similar in other aspects: length of complementarity-determining regions and framework regions, and distribution of consensus sites for SHMs. Finally, we demonstrated that monoclonal antibodies (mAbs) specific for an Ebola protein could be obtained from M. fascicularis tissue samples by phage display technology. In summary, the study provides new insight into the M. fascicularis V region gene repertoire and further supports the idea that macaque-derived mAbs may be of therapeutic value to humans.     

Blood Characteristics of the Crab-Eating Monkeys (Macaca fascicularis) in Bali Island,Indonesia: Implication of Water Deficiency in West Bali

Environmental effects on blood characteristics of macaques were examined by comparing serveral blood indices of the free-ranging crab-eating monkeys (Macaca fascicularis) in two distinct regions of Bali Island, Indonesia. The total plasma protein level and concentrations of' creatinine and sodium ion were higher with macaques of Teluk Terima in the west part of Bali Island (dry area) than those in the central Bali (wet area). Results indicated that water deficiency in the dry area significantly affects the blood characteristics of macaques.     

Plasma cholesterol levels in free-ranging macaques compared with captive macaques and humans

Plasma total cholesterol in free-ranging Japanese macaques (Macaca fuscata) on Koshima islet and in free-ranging long-tailed macaques (Macaca fascicularis) at Pangandaran in Indonesia was found to occur at very low levels compared with captive macaques and humans. Although total cholesterol levels in captive macaques were lower than humans, differences in HDL cholesterol levels were only small. In both sexes of wild and captive Japanese macaques, total cholesterol levels decreased from birth through to young adulthood but then increased in adult females of the captive group. In contrast, the value for adult females of the wild troop remained at a low level. Low TCH levels in adult females of the wild Japanese macaque troop may be due to a low energy intake and may have caused a delay in the onset of sexual maturation. Plasma TCH levels increased with the addition of 0.1% dietary cholesterol over six weeks in captive long-tailed macaques. That the cholesterol value after six weeks was dependent on cholesterol levels prior to supplementation indicates that captive macaques are slightly saturated with cholesterol.