Shiho Fujita

Male genetic structure and paternity in western lowland gorillas (Gorilla gorilla gorilla)

The male dispersal patterns of western lowland gorillas (WLGs, Gorilla gorilla gorilla) are not well understood. To determine whether most silverbacks stay close to their relatives, we analyzed autosomal and Y-chromosomal microsatellites (STRs) in wild WLGs at Moukalaba, Gabon. We obtained STR genotypes for 38 individuals, including eight silverbacks and 12 adult females in an approximately 40 km(2) area. Among them, 20 individuals were members of one identified group (Group Gentil; GG), including one silverback and six adult females. The silverback sired all 13 of the offspring in GG and no Y-STR polymorphism within GG was found, as expected in a one-male group structure. Over all silverbacks sampled, Y-STR diversity was high considering the limited sampling area, and silverbacks with similar Y-STR haplotypes were not always located in nearby areas. Although the misclassification rate of kinship estimates in this study was not negligible, there were no kin dyads among all silverbacks sampled. These results suggest that silverbacks born in the same group do not stay close to each other after maturation. The Y-STR diversity in this study was similar to that of a previous study conducted in an area that was approximately 150 times larger than our study area. Similarity of WLG Y-STR diversity between studies at different sampling scales suggests that male gene flow may not be geographically limited. These results suggest that WLG males normally disperse from their natal areas after maturation, at least, in Moukalaba.

Molecular identification of the causative agent of human strongyloidiasis acquired in Tanzania: dispersal and diversity of Strongyloides spp. and their hosts.

In order to identify the causative agent of imported strongyloidiasis found in a Japanese mammalogist, who participated in a field survey in Tanzania, the hyper-variable region IV (HVR-IV) of 18S ribosomal DNA and partial mitochondrial cytochrome c-oxidase subunit 1 gene (cox1) were analyzed and compared with Strongyloides fuelleborni collected from apes and monkeys of Africa and Japan, and S. stercoralis from humans, apes and dogs. The HVR-IV and cox1 of the patients worms were identical to or only slightly differed from those of worms parasitic in Tanzanian chimpanzees and yellow baboons, demonstrating that the patient acquired the infection during her field survey in Tanzania. Phylogenetic analysis with the maximum-likelihood method largely divided isolates of S. fuelleborni into three groups, which corresponded to geographical localities but not to host species. Meanwhile, isolates of S. stercoralis were grouped by the phylogenetic analysis into dog-parasitic and primate-parasitic clades, and not to geographical regions. It is surmised that subspeciation has occurred in S. fuelleborni during the dispersal of primates in Africa and Asia, while worldwide dispersal of S. stercoralis seems to have occurred more recently by migration and the activities of modern humans.

Bifidobacterium moukalabense sp. nov., isolated from the faeces of wild west lowland gorilla (Gorilla gorilla gorilla).

Gram-staining-positive anaerobic rods were isolated from the faeces of a wild lowland gorilla (Gorilla gorilla gorilla) in Moukalaba-Doudou National Park, Gabon, and strain GG01(T) was taxonomically investigated. Based on phylogenetic analyses and specific phenotypic characteristics, the strain belonged to the genus Bifidobacterium. Phylogenetic analysis of its 16S rRNA gene sequence revealed that strain GG01(T) formed a single monophyletic cluster and had a distinct line of descent. Based on 16S rRNA gene sequence similarity, the type strains of Bifidobacterium catenulatum JCM 1194(T) (98.3%) and Bifidobacterium pseudocatenulatum (98.1%) JCM 1200(T) were the most closely related to this novel strain, although it was clear that they belonged to different species. hsp60 sequences also supported these relationships. The DNA G+C content of this novel strain was 60.1 mol%. Bifidobacterium moukalabense sp. nov. (type strain GG01(T)u200a=u200aJCM 18751(T)u200a=u200aDSM 27321(T)) is proposed.

Interaction Between Male and Female Mating Strategies and Factors Affecting Reproductive Outcome

Japanese macaques (Macaca fuscata) have multimale–multifemale social groups, which provides for complex male and female mating strategies. According to the primate sexual selection theory, males fundamentally compete with rival males for access to females. Male mating strategies include direct male–male competition, sperm competition, and sneak copulation. On the other hand, females have a counterstrategy against male sexual coercion: extended receptivity, which functions to conceal the exact time of ovulation from males, and thus prevents individual males from monopolizing access to females. Female mating strategies include mate choice toward particular males, which brings a female or her offspring material and/or genetic benefits, and mating with multiple males to prevent infanticide through paternity confusion.

Prevalence and genetic diversity of Oesophagostomum stephanostomum in wild lowland gorillas at Moukalaba-Doudou National Park, Gabon

SummaryUsing a sedimentation method, the prevalence of the nodular worm Oesophagostomum stephanostomum (Nematoda: Strongylida) in western lowland gorillas at Moukalaba-Doudou National Park (MDNP), Gabon, was determined in fecal samples collected between January 2007 and October 2011, along with their coprocultures. Concurrently, possible zoonotic Oesophagostomum infections in villagers living near MDNP were assessed from their fecal samples collected during October and November of 2011. In the gorillas, strongylid (Oesophagostomum and/or hookworm) eggs were found in 47 of 235 fecal samples (20.0 %) and Oesophagostomum larvae were detected in 101 of 229 coprocultures (44.1 %). In the villagers, strongylid eggs were found in 9 of 71 fecal samples (12.7 %), but no Oesophagostomum larvae were detected in coprocultures. The internal transcribed spacer (ITS) region of ribosomal RNA gene (rDNA) and cytochrome c oxidase subunit-1 (cox-1) region of mitochondrial DNA (mtDNA) of coprocultured Oesophagostomum larvae were amplified using parasite DNA extracted from 7–25 larvae/sample, cloned into Escherichia coli, and sequenced. Sequenced rDNA contained 353/354-bp long ITS1, 151-bp long 5.8S rDNA, and 227-bp long ITS2. Parts of clones showed variations at 1–3 bases in the ITS1 region at a frequency of 24/68 (35.3 %) and at 1–2 bases in the ITS2 region at a frequency of 7/68 (10.3 %), whereas the 5.8S rDNA was essentially identical. Sequenced cox-1 gene of the parasites, 849 bp in length, showed a higher number of nucleotide variations, mainly at the third nucleotide position of the codon. The majority of clones (27/41 (65.9 %)) had an identical amino acid sequence. These results suggest that at MDNP, Gabon, only a single population of O. stephanostomum with a degree of genetic diversity is prevalent in western lowland gorillas, without zoonotic complication in local inhabitants. The possible genetic variations in the ITS region of rDNA and cox-1gene of mtDNA presented here may be valuable when only a limited amount of material is available for the molecular species diagnosis of O. stephanostomum.

The Demography and Reproductive Parameters of Bossou Chimpanzees

Ecological and behavioral research on chimpanzees at Bossou has been ongoing for more than 30 years, ever since 1976. This community exhibits quite unique life history variables, including demographic and reproductive parameters. The chimpanzees of Bossou develop and mature faster than do those in other chimpanzee populations. The interbirth interval is shorter, and females continue to give birth at least until 45 years of age. Perhaps Bossou provides an excellent habitat for chimpanzees. However, community size has never exceeded 23 and has remained stable for nearly three decades, numbering about 20 individuals. A flu-like epidemic in 2003, however, led to the loss of five individuals; the community has numbered between 12 and 14 members since 2006. Most offspring, males as well as females, disappear from Bossou during their adolescence. Patterns of emigration and immigration are discussed here. It is argued that although the habitat of the Bossou chimpanzees may be limited in its carrying capacity, it has nevertheless favored reproductive development in the females.

Ranging behavior of Mahale chimpanzees: a 16 year study.

We have analyzed the ranging patterns of the Mimikire group (M group) of chimpanzees in the Mahale Mountains National Park, Tanzania. During 16xa0years, the chimpanzees moved over a total area of 25.2 or 27.4xa0km2, as estimated by the grid-cell or minimum convex polygon (MCP) methods, respectively. Annually, the M group used an average of 18.4xa0km2, or approximately 70xa0%, of the total home-range area. The chimpanzees had used 80xa0% of their total home range after 5xa0years and 95xa0% after 11xa0years. M group chimpanzees were observed more than half of the time in areas that composed only 15xa0% of their total home range. Thus, they typically moved over limited areas, visiting other parts of their range only occasionally. On average, the chimpanzees used 7.6xa0km2 (in MCP) per month. Mean monthly range size was smallest at the end of the rainy season and largest at the end of the dry season, but there was much variability from year to year. The chimpanzees used many of the same areas every year when Sabacomorensis fruits were abundant between August and January. In contrast, the chimpanzees used several different areas of their range in June. Here range overlap between years was relatively small. Over the 16xa0years of the study we found that the M group reduced their use of the northern part of their range and increased their frequency of visits to the eastern mountainous side of their home range. Changes in home-range size correlated positively with the number of adult females but not with the number of adult males. This finding does not support a prediction of the male-defended territory model proposed for some East African chimpanzee unit-groups.

Molecular features of hookworm larvae (Necator spp.) raised by coproculture from Ugandan chimpanzees and Gabonese gorillas and humans.

Species composition of Necator hookworms was surveyed in (i) Ugandan chimpanzees living around farms and villages at Bulindi, (ii) Gabonese gorillas under habituation in Moukalaba-Doudou National Park (MDNP), and (iii) Gabonese villagers living adjacent to MDNP. Internal transcribed spacers (ITS) of rDNA and partial cytochrome c oxidase subunit 1 (Cox1) gene of mtDNA were analyzed from larvae obtained by coproculture. Three ITS types (I, II and III) and three Cox1 haplotype groups (A, B and C) were demonstrated. ITS type I and Cox1 haplotype group A, representing Necator americanus, were demonstrated in the hookworm larvae from Gabonese gorillas and humans, but not from Ugandan chimpanzees. Type II and haplotype groups B and C, presumably representing N. gorillae, were found in larvae from Ugandan chimpanzees and Gabonese gorillas and humans. These features were overall similar with those found previously in the Central African Republic. Meanwhile, type III was proven in a larva from a Gabonese gorilla as the first demonstration from a non-human primate. Cox1 haplotypes obtained from Ugandan chimpanzees formed a subgroup within group B, presumably reflecting dispersal and diversification processes of the apes.

Molecular epidemiological study of adenovirus infecting western lowland gorillas and humans in and around Moukalaba-Doudou National Park (Gabon).

Adenoviruses are widespread in human population as well as in great apes, although the data about the naturally occurring adenovirus infections remain rare. We conducted the surveillance of adenovirus infection in wild western lowland gorillas in Moukalaba-Doudou National Park (Gabon), in order to investigate naturally occurring adenovirus in target gorillas and tested specifically a possible zoonotic transmission with local people inhabiting the vicinity of the park. Fecal samples were collected from western lowland gorillas and humans, and analyzed by PCR. We detected adenoviral genes in samples from both gorillas and the local people living around the national park, respectively: the overall prevalence rates of adenovirus were 24.1 and 35.0xa0% in gorillas and humans, respectively. Sequencing revealed that the adenoviruses detected in the gorillas were members of Human mastadenovirus B (HAdV-B), HAdV-C, or HAdV-E, and those in the humans belonged to HAdV-C or HAdV-D. Although HAdV-C members were detected in both gorillas and humans, phylogenetic analysis revealed that the virus detected in gorillas are genetically distinct from those detected in humans. The HAdV-C constitutes a single host lineage which is compatible with the host-pathogen divergence. However, HAdV-B and HAdV-E are constituted by multiple host lineages. Moreover, there is no evidence of zoonotic transmission thus far. Since the gorilla-to-human transmission of adenovirus has been shown before, the current monitoring should be continued in a broader scale for getting more insights in the natural history of naturally occurring adenoviruses and for the safe management of gorillas’ populations.

Lactobacillus gorillae sp. nov., isolated from the faeces of captive and wild western lowland gorillas (Gorilla gorilla gorilla)

Four strains of Gram-staining-positive, anaerobic rods were isolated from the faeces of western lowland gorillas (Gorilla gorilla gorilla). Three strains, KZ01(T), KZ02 and KZ03, were isolated at the Kyoto City Zoo, Japan, and one strain, GG02, was isolated in the Moukalaba-Doudou National Park, Gabon. These strains were investigated taxonomically. These strains belonged to the Lactobacillus reuteri phylogenetic group according to phylogenetic analysis based on 16S rRNA gene sequences and specific phenotypic characteristics. Phylogenetic analysis of their 16S rRNA gene sequences revealed that strains KZ01(T), KZ02, KZ03 and GG02 formed a single monophyletic cluster and had a distinct line of descent. Based on sequence similarity of the 16S rRNA gene, Lactobacillus fermentum JCM 1173(T) (96.6u200a%) was the closest neighbour to these novel strains, although it was clear that these strains belonged to a different species. Partial pheS sequences also supported these relationships. DNA-DNA relatedness between strain KZ01(T) and L. fermentum JCM 1173(T) was less than 22u200a% and the DNA G+C content of strain KZ01(T) was 50.7 mol%. The cell-wall peptidoglycan type was A4β (l-Orn-d-Asp) and the major fatty acids were C16u200a:u200a0, C18u200a:u200a1ω9c and C19u200a:u200a1 cyclo 9,10. Therefore, based on phylogenetic, phenotypic and physiological evidence, these strains represent a novel species of the genus Lactobacillus, for which the name Lactobacillus gorillae sp. nov. is proposed. The type strain is KZ01(T) (u200a=u200aJCM 19575(T)u200a=u200aDSM 28356(T)).