Measuring heart rate in captive chimpanzees without anesthesia.

Heart rate measurements can be useful for the monitoring of both physical and mental condition in humans and nonhuman animals. Yet, information about heart rates in chimpanzees, who are phylogenetically the closest species to humans, is scarce. Existing data on chimpanzee heart rates have mainly been collected from chimpanzees under anesthesia.

Hepatitis C virus infection reduces the lifespan of chimpanzees used in biomedical research.

Chimpanzees were used in hepatitis research for over three decades with the aim to identify and develop treatments for the virus, a leading cause of chronic liver disease in humans. We used a dataset of 120 chimpanzees housed at a single institution in Japan, 22 of whom became chronically infected with hepatitis C virus (HCV), to examine whether HCV infection results in a reduced lifespan as reported in humans. Survival analysis showed that HCV carriers experienced a higher mortality risk compared with non-carriers.

Structural variations of subterminal satellite blocks and their source mechanisms as inferred from the meiotic configurations of chimpanzee chromosome termini.

African great apes have large constitutive heterochromatin (C-band) blocks in subtelomeric regions of the majority of their chromosomes, but humans lack these. Additionally, the chimpanzee meiotic cell division process demonstrates unique partial terminal associations in the first meiotic prophase (pachytene). These are likely formed as a result of interaction among subtelomeric C-band blocks.

Estimation of chimpanzee age based on DNA methylation.

In wild animal conservation, knowing the age of an individual animal is extremely beneficial. However, estimating the age is difficult for many species. Recently, epigenetics-based methods of estimating age have been reported.

Human-specific features of spatial gene expression and regulation in eight brain regions.

Molecular maps of the human brain alone do not inform us of the features unique to humans. Yet, the identification of these features is important for understanding both the evolution and nature of human cognition. Here, we approached this question by analyzing gene expression and H3K27ac chromatin modification data collected in eight brain regions of humans, chimpanzees, gorillas, a gibbon, and macaques.

Chimpanzee Down syndrome: a case study of trisomy 22 in a captive chimpanzee.

We report a case of chimpanzee trisomy 22 in a captive-born female. Because chromosome 22 in great apes is homologous to human chromosome 21, the present case is analogous to human trisomy 21, also called Down syndrome. The chimpanzee in the present case experienced retarded growth; infantile cataract and vision problems, including nystagmus, strabismus, and keratoconus; congenital atrial septal defect; and hypodontia.

Chimpanzee Personality and the Arginine Vasopressin Receptor 1A Genotype.

Polymorphisms of the arginine vasopressin receptor 1a (AVPR1a) gene have been linked to various measures related to human social behavior, including sibling conflict and agreeableness. In chimpanzees, AVPR1a polymorphisms have been associated with traits important for social interactions, including sociability, joint attention, dominance, conscientiousness, and hierarchical personality dimensions named low alpha/stability, disinhibition, and negative emotionality/low dominance. We examined associations between AVPR1a and six personality domains and hierarchical personality dimensions in 129 chimpanzees (Pan troglodytes) living in Japan or in a sanctuary in Guinea.

A case of maxillary sarcoma in a chimpanzee (Pan troglodytes).

Oral malignancy is rare in chimpanzees. A 34-year-old female chimpanzee (Pan troglodytes) at Kumamoto Sanctuary, Japan, had developed it. Treatment is technically difficult for chimpanzees while malignant neoplasm is seemingly rising in captive populations.

Regional DNA methylation differences between humans and chimpanzees are associated with genetic changes, transcriptional divergence and disease genes.

Changes in gene expression have been proposed to have an important role in the evolutionary changes in phenotypes. Interspecific changes in gene expression can result not only from genetic changes in regulatory regions but also from epigenetic changes in such regions. Here we report the identification of genomic regions showing differences in DNA methylation between humans and chimpanzees (termed S-DMRs for species-specific differentially methylated regions) on chromosomes 21 and 22.

Human-specific SNP in obesity genes, adrenergic receptor beta2 (ADRB2), Beta3 (ADRB3), and PPAR γ2 (PPARG), during primate evolution.

Unlabelled: Adrenergic-receptor beta2 (ADRB2) and beta3 (ADRB3) are obesity genes that play a key role in the regulation of energy balance by increasing lipolysis and thermogenesis. The Glu27 allele in ADRB2 and the Arg64 allele in ADRB3 are associated with abdominal obesity and early onset of non-insulin-dependent diabetes mellitus (NIDDM) in many ethnic groups. Peroxisome proliferator-activated receptor γ (PPARG) is required for adipocyte differentiation.

Eco-geographical diversification of bitter taste receptor genes (TAS2Rs) among subspecies of chimpanzees (Pan troglodytes).

Chimpanzees (Pan troglodytes) have region-specific difference in dietary repertoires from East to West across tropical Africa. Such differences may result from different genetic backgrounds in addition to cultural variations. We analyzed the sequences of all bitter taste receptor genes (cTAS2Rs) in a total of 59 chimpanzees, including 4 putative subspecies.

Polymorphism of the tryptophan hydroxylase 2 (TPH2) gene is associated with chimpanzee neuroticism.

In the brain, serotonin production is controlled by tryptophan hydroxylase 2 (TPH2), a genotype. Previous studies found that mutations on the TPH2 locus in humans were associated with depression and studies of mice and studies of rhesus macaques have shown that the TPH2 locus was involved with aggressive behavior. We previously reported a functional single nucleotide polymorphism (SNP) in the form of an amino acid substitution, Q468R, in the chimpanzee TPH2 gene coding region.

[Leprosy in a chimpanzee].

Leprosy is suspected to develop after a long period of latency following infection with Mycobacterium leprae (M. leprae) during infancy, but definitive proof has been lacking. We found a rare case of leprosy in a chimpanzee (Pan troglodytes) born in West Africa (Sierra Leone) and brought to Japan around 2 years of age.

Diversification of bitter taste receptor gene family in western chimpanzees.

In mammals, bitter taste is mediated by T2R genes, which belong to the large family of seven transmembrane G protein-coupled receptors. Because T2Rs are directly involved in the interaction between mammals and their dietary sources, it is likely that these genes evolved to reflect species' specific diets during mammalian evolution. Here, we investigated the sequences of all 28 putative functional chimpanzee T2R genes (cT2Rs) in 46 western chimpanzees to compare the intraspecies variations in chimpanzees to those already known for all 25 human functional T2R genes (hT2Rs).

Infection during infancy and long incubation period of leprosy suggested in a case of a chimpanzee used for medical research.

The length of the incubation period of leprosy following Mycobacterium leprae infection has never been conclusively determined, owing to the lack of a method to demonstrate the presence of an asymptomatic infection. We report a rare case of leprosy in a chimpanzee in which a 30-year incubation period was strongly suggested by single nucleotide polymorphism (SNP) analysis.

Identification of Plasmodium malariae, a human malaria parasite, in imported chimpanzees.

It is widely believed that human malaria parasites infect only man as a natural host. However, earlier morphological observations suggest that great apes are likely to be natural reservoirs as well. To identify malaria parasites in great apes, we screened 60 chimpanzees imported into Japan.

Assessing chimpanzee personality and subjective well-being in Japan.

We tested whether the cultural background of raters influenced ratings of chimpanzee personality. Our study involved comparing personality and subjective well-being ratings of 146 chimpanzees in Japan that were housed in zoos, research institutes, and a retirement sanctuary to ratings of chimpanzees in US and Australian zoos. Personality ratings were made on a translated and expanded version of a questionnaire used to rate chimpanzees in the US and Australia.

Chimpanzee pinworm, Enterobius anthropopitheci (Nematoda: Oxyuridae), maintained for more than twenty years in captive chimpanzees in Japan.

The chimpanzee pinworm, Enterobius anthropopitheci (Gedoelst, 1916), was found in chimpanzees, Pan troglodytes, reared in Kumamoto Primate Research Park, Sanwa Kagaku Kenkyusho Co., Ltd., Kumamoto, Japan, in 2006.

Identification of a protanomalous chimpanzee by molecular genetic and electroretinogram analyses.

We determined the structures of long (L)-wavelength-sensitive and middle (M)-wavelength-sensitive opsin gene array of 58 male chimpanzees and we investigated relative sensitivity to red and green lights by electroretinogram flicker photometry. One subject had protanomalous color vision, while others had normal color vision. Unlike in humans, a polymorphic difference in the copy number of the genes and a polymorphic base substitution at amino acid position 180 were not frequently observed in chimpanzees.

Normal vaginal flora in chimpanzees (Pan troglodytes): qualitative and quantitative study.

Lactobacilli are the predominant microorganisms in the vaginal flora of human beings, and are known to play an important role in protecting them from genital infections. On the other hand, the composition of the vaginal flora differs among laboratory animal species, and lactobacilli are not the predominant vaginal microorganism in many laboratory animals. We speculated that the vaginal flora of chimpanzees would be more similar to those of human beings than to those of other animal species, because chimpanzees are phylogenetically close to human beings, and their reproductive physiology is similar to that of human beings.

Body, head, and facial growth: comparison between macaques (Macaca fuscata) and chimpanzee (Pan troglodytes) based on somatometry.

Chimpanzees and macaques were compared in their growth of head, face and body, based on a large-scale somatometrical database. Their growth stages, i to v, were determined by inflection points in velocity curves. Sex differences in their growth are shown both by elongated stages in juvenile and adolescent and by the greater velocity in males in the stages.

Branch retinal artery occlusion: a complication of iron-deficiency anemia in a young adult with a rectal carcinoid.

We report a case of branch retinal artery occlusion (BRAO) in a patient with iron-deficiency anemia. Various ophthalmological and laboratory studies were performed. A 32-year-old man had a sudden decrease of vision in his left eye to counting fingers at 30 cm two days ago.

Endocrinologic comparison of activin a secretion during pregnancy and early lactation in Japanese monkeys, chimpanzees, and humans.

Secretion of activin A in Japanese monkeys and chimpanzees during pregnancy and early postpartum periods was investigated, and the results were compared with those in humans. Plasma activin A increased throughout pregnancy in Japanese monkeys, and the level was significantly higher in the third and fourth quarters than in the first quarter. After parturition in the Japanese monkey, circulating activin A decreased to levels seen during the normal menstrual cycle.

Bilateral central retinal artery occlusion in Churg-Strauss syndrome.

Purpose: To describe a rare bilateral central retinal artery occlusion in a patient with Churg-Strauss syndrome.

Design: Observational case report.

Methods: A 68-year-old Japanese man with Churg-Strauss syndrome developed sudden vision loss in both eyes.