ABSTRACT
While investigating the genetic structure in wild bonobos,(1) we realized that the widely accepted scenario positing that the Pleistocene appearance of the Congo River separated the common ancestor of chimpanzees (Pan troglodytes) and bonobos (P. paniscus) into two species is not supported by recent geographical knowledge about the formation of the Congo River. We explored the origin of bonobos using a broader biogeographical perspective by examining local faunas in the central African region. The submarine Congo River sediments and paleotopography of central Africa show that the Congo River has functioned as a geographical barrier for the last 34 million years. This evidence allows us to hypothesize that when the river was first formed, the ancestor of bonobos did not inhabit the current range of the species on the left bank of the Congo River but that, during rare times when the Congo River discharge decreased during the Pleistocene, one or more founder populations of ancestral Pan paniscus crossed the river to its left bank. The proposed scenario for formation of the Congo River and the corridor hypothesis for an ancestral bonobo population is key to understanding the distribution of great apes and their evolution.
Subject(s)
Animal Migration , Pan paniscus/physiology , Rivers , Africa, Central , Animals , Anthropology, Physical , Biological EvolutionABSTRACT
Arthropodal natural enemies respond to volatiles from plants infested by their prey/host herbivores (herbivore-induced plant volatiles; HIPVs). However, the relative importance of HIPV blends vs. each compound in the blend in attracting natural enemies is not fully understood. In this study, we investigated the response of a parasitic wasp, Aphidius ervi, to HIPVs that were specific or nonspecific to infestations by its host aphid, Acyrthosiphon pisum. To select such compounds, we compared the volatiles emitted from broad bean plants infested by either A. pisum (host) or by Aphis craccivora (nonhost), and selected the host-specific HIPVs ß-myrcene, n-octanal, and α-phellandrene, and host-nonspecific HIPVs (E)-ß-ocimene, γ-terpinene, and linalool as test compounds. For each compound, we used a range that covered the amounts emitted from infested broad bean plants for bioassays. Female wasps preferred n-octanal and (E)-ß-ocimene at 10-ng and 30-ng doses over clean air. Interestingly, the wasps preferred α-phellandrene at 0.1-ng and 30-ng doses, but not at 1-ng and 10-ng doses. The wasps repelled linalool over clean air at 1-ng and 0.1-ng doses. We then mixed the equivalent amounts of the six compounds to test the effect of the blend. The wasps responded to a blend of six HIPV components at all concentrations tested (0.001 ng each to 5 ng each). These results suggested that the blend provided more useful information for female wasps than the individual compounds. The possible use of the single component and the blend for the biological control of A. ervi is discussed.
Subject(s)
Aphids/physiology , Herbivory , Host-Parasite Interactions , Vicia faba/parasitology , Volatile Organic Compounds/metabolism , Wasps/physiology , Animals , Aphids/parasitology , Female , Male , Pest Control, Biological , Vicia faba/physiology , Wasps/parasitologyABSTRACT
To date, the major role of HPV16E6 in cancer has been considered to be its ability to inhibit the p53 tumor-suppressor protein, thereby thwarting p53-mediated cytotoxic responses to cellular stress signals. Here, we show that HPV16E6-dependent c-fos oncogenic protein expression contributes to AP-1 complex formation under oxidative stress in SiHa cells (HPV16-positive squamous cell carcinoma of the cervix). In addition, we examined the role of HPV16E6 in TGF-α-induced c-fos expression and found that the c-fos protein expression induced by TGF-α is HPV16E6 dependent. Thus, our results provide the first evidence that HPV16E6 contributes to AP-1 complex formation after both ligand-dependent and independent EGFR activation, suggesting a new therapeutic approach to the treatment of HPV-associated tumors.
Subject(s)
Oncogene Proteins, Viral/metabolism , Proto-Oncogene Proteins c-fos/metabolism , Repressor Proteins/metabolism , Transcription Factor AP-1/metabolism , Cell Line, Tumor , Female , Gene Expression Regulation, Neoplastic , Humans , Oncogene Proteins, Viral/genetics , Proto-Oncogene Proteins c-fos/genetics , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Repressor Proteins/genetics , Transcription Factor AP-1/genetics , Transforming Growth Factor alpha/metabolism , Uterine Cervical Neoplasms/metabolism , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/virologyABSTRACT
The importance of sleep in maintaining cognitive functions such as learning and memory has been reported in both vertebrates and invertebrates. Previous studies demonstrated that sleep deprivation impaired the olfactory memory retention of fruit flies as described in the classical conditioning paradigm. Here, we show that sleep deprivation leads to a preference for the odours of the rearing environment in Drosophila melanogaster. Flies whose sleep had been disturbed with periodic rotation stimuli during night-time preferred apple cider vinegar (ACV) to broth, while this preference was lower in flies without sleep deprivation and those rotated during daytime. Experiments using single odours showed an increase in responses to ACV due to sleep deprivation. These results suggest that sleep functions in food odour preference. Flies grown on medium supplemented with ACV showed greater preference for ACV, and those grown with broth supplementation showed a greater preference for broth under sleep-deprived conditions. These results suggest that flies with night-time sleep deprivation become attached to the environment on which they have developed, and that sleep contributes to preference for novel food odours. This study offers an approach to investigating the interaction between sleep and neural disorders concerning cognitive deficits towards novel stimuli.
Subject(s)
Drosophila melanogaster/physiology , Food Preferences , Locomotion , Odorants/analysis , Olfactory Perception/physiology , Sleep Deprivation/physiopathology , Smell , Animals , Conditioning, Classical , Female , MaleABSTRACT
One of the current threats to the bonobo (Pan paniscus), a highly endangered ape species only found in the Democratic Republic of the Congo, are anthropozoonoses caused by human respiratory viruses. To date, epidemiological information regarding respiratory viral infections in bonobos is limited. In this study, we examined fecal immunoglobulin A antibodies against human respiratory viruses in bonobos, which may help estimating the viral prevalence. A substantial proportion of bonobos were positive for the antiviral antibodies, including those against parainfluenza virus, respiratory syncytial virus, influenza virus, rhinovirus, and mumps virus. The prevalence of the antibodies was found to depend on the viral species and bonobo populations, suggesting that the bonobos had been exposed to these respiratory viruses. These results may indicate the need for an epidemiological evidence-based action plan for the protection of bonobos from anthropozoonoses.
Subject(s)
Pan paniscus , Viruses , Animals , Feces , Humans , Pan troglodytes , PrevalenceABSTRACT
Patterns of kinship among individuals in different groups have been rarely examined in animals. Two closest living relatives of humans, bonobos and chimpanzees share many characteristics of social systems including male philopatry, whereas one major difference between the two species is the nature of intergroup relationship. Intergroup relationship is basically antagonistic and males sometimes kill individuals of other groups in chimpanzees, whereas it is much more moderate in bonobos and copulations between individuals of different groups are often observed during intergroup encounters. Such behavioural differences may facilitate more frequent between-group male gene flow and greater between-group differentiation in male kinship in bonobos than in chimpanzees. Here we compared differences between average relatedness among males within groups and that among males of neighbouring groups, and between-group male genetic distance between bonobos and chimpanzees. Contrary to expectation, the differences between average relatedness among males within groups and that among males of neighbouring groups were significantly greater in bonobos than in chimpanzees. There were no significant differences in autosomal and Y-chromosomal between-group male genetic distance between the two species. Our results showed that intergroup male kinship is similarly or more differentiated in bonobos than in chimpanzees.
Subject(s)
Pan paniscus/genetics , Pan troglodytes/genetics , Animals , Genetic Variation , Male , Phylogeny , Social BehaviorABSTRACT
Inflammation is associated with disease progression and, by largely unknown mechanisms, has been said to drive oncogenesis. At inflamed sites, neutrophils deploy a potent antimicrobial arsenal that includes proteinases, antimicrobial peptides, and ROS. Reactive oxygen species (ROSs) induce chemokines. In the present study, the concentrations of IL-8 in culture supernatants of HeLa cells treated with ROS were determined by enzyme-linked immunosorbent assay. We used o-phenanthroline to deplete Fe(2+) in order to investigate the mechanisms through which ROSs induce IL-8 secretion in our system. The iron chelator o-phenanthroline effectively inhibited H(2)O(2)-induced ERK2 activation. Enzyme-linked immunosorbent assays showed that IL-8 protein secretion was elevated in ROS-treated HeLa cells. When Fe(2+) was removed from these cells, IL-8 secretion was inhibited. Collectively, these results indicate that Fe(2+)-mediated Erk pathway activation is an important signal transduction pathway in ROS-induced IL-8 secretion in epithelial cells.
Subject(s)
Chemokines/metabolism , Epithelial Cells/metabolism , Gene Expression Regulation , Interleukin-8/metabolism , Iron/metabolism , Oxygen/metabolism , Anti-Infective Agents/pharmacology , Enzyme-Linked Immunosorbent Assay/methods , Extracellular Signal-Regulated MAP Kinases/metabolism , HeLa Cells , Humans , Hydrogen Peroxide/chemistry , Phenanthrolines/pharmacology , Reactive Oxygen Species , Signal TransductionABSTRACT
An entomopathogenic fungus, Cordyceps sp. has been known to produce cordycepin which is a purine nucleoside antimetabolite and antibiotic with potential anticancer, antioxidant and anti-inflammatory activities. Interestingly, Cordyceps militaris produces significantly higher amount in a liquid surface culture than in a submerged culture. The liquid surface culture consists of mycelia growing into the air (aerial mycelia) and mycelia growing toward the bottom into the medium (submerged mycelia). In this study, to clarify roles of aerial and submerged mycelia of C. militaris in the cordycepin production the difference in metabolism between these mycelia was investigated. From transcriptomic analyses of the aerial and submerged mycelia at the culture of 5, 12 and 19 days, the metabolism of the submerged mycelia switched from the oxidative phosphorylation to the fermentation pathway. This activated the pentose phosphate pathway to provide building block materials for the nucleotide biosynthetic pathway. Under hypoxic conditions, the 5-aminolevulinic acid synthase (CCM_01504), delta-aminolevulinic acid dehydratase (CCM_00935), coproporphyrinogen III oxidase (CCM_07483) and cytochrome c oxidase 15 (CCM_05057) genes of heme biosynthesis were significantly upregulated. In addition, the liquid surface culture revealed that metabolite coproporhyrinogen III and glycine, the product and precursor of heme, were increased at 12th day and decreased at 19th day, respectively. These results indicate that the submerged mycelia induce the activation of iron acquisition, the ergosterol biosynthetic pathway, and the iron cluster genes of cordycepin biosynthesis in a hypoxic condition. Even though, the expression of the cluster genes of cordycepin biosynthesis was not significantly different in both types of mycelia.
Subject(s)
Antibiotics, Antineoplastic/metabolism , Cordyceps/growth & development , Cordyceps/metabolism , Culture Media , Deoxyadenosines/metabolism , Mycelium/growth & development , Mycelium/metabolism , Gene Expression Profiling , Metabolic Networks and Pathways/geneticsABSTRACT
Soaking and maceration of dry soybean seeds induce the formation of aliphatic volatile compounds that impact the flavor properties of food products prepared from soybean. Most aliphatic volatile compounds are formed through oxygenation of unsaturated fatty acids by lipoxygenases; however, lipoxygenases are not responsible for the formation of 1-octen-3-ol. 1-Octen-3-ol in soybean products is in general an off-flavor compound; thus, a procedure to manage its formation is required. In this study, we show that the formation of 1-octen-3-ol after hydration of soybean seed powder is independent of oxygen, suggesting that 1-octen-3-ol is not formed de novo from unsaturated fatty acids but instead from its derivative. When crude methanol extract of soybean seeds was reacted with ß-glycosidases, 1-octen-3-ol was rather liberated from its glycoside. We purified the parent glycoside from soybean seeds and confirmed it as ( R)-1-octen-3-yl ß-primeveroside [( R)-1-octen-3-yl 6- O-ß-d-xylopyranosyl-ß-d-glucopyranoside]. Green immature soybean fruits (pericarp and seeds) contain a high amount of 1-octen-3-yl ß-primeveroside. Its amount decreases after hydration of dry soybean powder. The results indicate that management of 1-octen-3-ol levels in soybean products requires a different strategy than that applied to off-flavor compounds formed de novo.
Subject(s)
Glycine max/chemistry , Glycosides/analysis , Octanols/analysis , Food Handling , Seeds/chemistryABSTRACT
Bipedalism, terrestriality and open habitat were thought to be linked to each other in the course of human evolution. However, recent paleontological evidence has revealed that early hominins evolved in a wooded, humid environment. Did the evolutionary process from arboreal to terrestrial life actually require open habitat? Here I report the seasonal change in forest utilization height of West African chimpanzees (Pan troglodytes) and central African bonobos (Pan paniscus), and show that the difference in terrestriality between these two species was mainly caused by ambient temperature differences between the two study sites. The key factor was the vertical structure of the microclimate in forests and its seasonality. The results suggest the possibility that human terrestrial life began inside a forest rather than in the savannah. Increasing seasonality and prolongation of the dry months throughout the late Miocene epoch alone could have promoted terrestrial life of our human ancestors.
Subject(s)
Biological Evolution , Ecosystem , Hominidae/physiology , Microclimate , Pan paniscus/physiology , Pan troglodytes/physiology , Animals , Behavior, Animal , Forests , TemperatureABSTRACT
We report here where the most recent common ancestor (MRCA) of bonobos (Pan paniscus) ranged and how they dispersed throughout their current habitat. Mitochondrial DNA (mtDNA) molecular dating to analyze the time to MRCA (TMRCA) and the major mtDNA haplogroups of wild bonobos were performed using new estimations of divergence time of bonobos from other Pan species to investigate the dispersal routes of bonobos over the forest area of the Congo River's left bank. The TMRCA of bonobos was estimated to be 0.64 or 0.95 million years ago (Ma). Six major haplogroups had very old origins of 0.38 Ma or older. The reconstruction of the ancestral area revealed the mitochondrial ancestor of the bonobo populations ranged in the eastern area of the current bonobos' habitat. The haplogroups may have been formed from either the riparian forests along the Congo River or the center of the southern Congo Basin. Fragmentation of the forest refugia during the cooler periods may have greatly affected the formation of the genetic structure of bonobo populations.
Subject(s)
DNA, Mitochondrial/genetics , Evolution, Molecular , Haplotypes , Pan paniscus/genetics , Animals , PhylogenyABSTRACT
Treatment of CuCl2 with a bis-benzimidazole-type ligand, p-bbiteb, afforded a new 2D coordination polymer bearing cationic Cu2L4 cages on the sheet framework. The regular arrangement of the cages created channel-like space for anions. The compound removed ClO4(-) and NO3(-) from aqueous solutions by exchange with Cl(-) in the channels.
ABSTRACT
A recently developed method enabled us to simultaneously characterize and quantitate glycosidically bound volatiles (GBVs) at picomole levels using liquid chromatography-mass spectrometry (LC-MS). On the basis of the analytical data it is possible to screen tea varieties most suitable for black tea processing, in which higher concentrations of primeverosides accumulate. The primeverosides decreased at the rolling step in black tea processing, whereas the glucopyranosides did not change much. The total contents of GBVs gradually increased at the withering steps and then remarkably increased after the fixing step at 230 °C, during oolong tea processing. The presence of 6'-O-malonyl ester type ß-D-glucopyranosides in the tea samples suggested a contribution to the increment in glucopyranosides during oolong tea processing. The method was also used to analyze GBVs and their derivatives to understand their possible role in the metabolic pathway of tea.
Subject(s)
Camellia sinensis/chemistry , Glycosides/chemistry , Plant Extracts/chemistry , Volatile Organic Compounds/chemistry , Food Handling , Gas Chromatography-Mass Spectrometry , Kinetics , Odorants/analysis , Plant Leaves/chemistryABSTRACT
Lymphocryptovirus (LCV) is one of the major gena in the herpesvirus family and is widely disseminated among primates. LCVs of human and rhesus macaques are shown to be causative agents of a number of malignant diseases including lymphoma and carcinoma. Bonobos (Pan paniscus) are highly endangered and the least studied species of the great apes. Considering the potential pathogenicity of the LCV that might threaten the fate of wild bonobos, population-based epidemiological information in terms of LCV prevalence in different location of Bonobo's habitats will help propose improved conservation strategies for the bonobos. However, such data are not available yet because it is very difficult to collect blood samples in the wild and thus virtually impossible to conduct sero-epidemiological study on the wild ape. In order to overcome this issue, we focused on evaluating anti-LCV IgA in the feces of bonobos, which are available in a non-invasive manner. Preliminary study showed that anti-LCV IgA but not IgG was efficiently and reproducibly detected in the feces of captive chimpanzees. It is noteworthy that the fecal IgA-positive individuals were seropositive for both anti-LCV IgG and IgA and that the IgA antibodies in both sera and feces were also detectable by Western blotting assay. These results indicate that the detection of fecal anti-LCV IgA is likely a reliable and feasible for epidemiological surveillance of LCV prevalence in the great apes. We then applied this method and found that 31% of wild bonobos tested were positive for anti-LCV IgA antibody in the feces. Notably, the positivity rates varied extensively among their sampled populations. In conclusion, our results in this study demonstrate that LCV is highly disseminated among wild bonobos while the prevalence is remarkably diverse in their population-dependent manner.
ABSTRACT
Based on field research and experimental treatments of trees, we investigated the formation of the brush-like shape of digging sticks used by chimpanzees (Pan troglodytes troglodytes). Evidence obtained in the field consisted of digging sticks found in Mboete, Equatorial Guinea, which is a newly reported locality for this type of tool, and Campo, Cameroon. Digging sticks used by chimpanzees in these areas had a brush-like shape at one end, which was quite different from the other end that was probably used for digging. In our tree-breaking experiment, 8 out of 17 species acquired a typical brush-like shape without human modification when broken off, and the shapes of the stumps were similar to those found in the field. Other species did not acquire the brush-like shape naturally or even after human modifications, and the stumps had different shapes from those found in the field. Our findings suggest that the brush-like shapes of digging sticks are often naturally formed when broken off from trees, depending on the nature of the fibre structure, and that the brush-like end is not used as the digging tool. We conclude that the vegetation surrounding termite mounds might influence how chimpanzees combine different types of tools, i.e., digging stick, brush-stick and fishing tool, for obtaining termites.
Subject(s)
Behavior, Animal/physiology , Feeding Behavior/physiology , Pan troglodytes/physiology , Trees/anatomy & histology , Animals , Equatorial Guinea , Plant Stems/anatomy & histologyABSTRACT
In late summer, heteroecious aphids, such as the potato aphid, Macrosiphum euphorbiae, move from their secondary summer host plants to primary host plants, where the sexual oviparae mate and lay diapausing eggs. We tested the hypothesis that volatiles of the primary host, Rosa rugosa, would attract the gynoparae, the parthenogenetic alate morph that produce oviparae, as well as the alate males foraging for suitable mates. In wind tunnel assays, both gynoparae and males oriented towards and reached rose cuttings significantly more often than other odour sources, including potato, a major secondary host. The response of males was as high to rose cuttings alone as to potato with a calling virgin oviparous female. These findings are discussed within the seasonal ecology of host alternating aphids.
ABSTRACT
Bonobos (Pan paniscus) inhabit regions south of the Congo River including all areas between its southerly tributaries. To investigate the genetic diversity and evolutionary relationship among bonobo populations, we sequenced mitochondrial DNA from 376 fecal samples collected in seven study populations located within the eastern and western limits of the species' range. In 136 effective samples from different individuals (range: 7-37 per population), we distinguished 54 haplotypes in six clades (A1, A2, B1, B2, C, D), which included a newly identified clade (D). MtDNA haplotypes were regionally clustered; 83 percent of haplotypes were locality-specific. The distribution of haplotypes across populations and the genetic diversity within populations thus showed highly geographical patterns. Using population distance measures, seven populations were categorized in three clusters: the east, central, and west cohorts. Although further elucidation of historical changes in the geological setting is required, the geographical patterns of genetic diversity seem to be shaped by paleoenvironmental changes during the Pleistocene. The present day riverine barriers appeared to have a weak effect on gene flow among populations, except for the Lomami River, which separates the TL2 population from the others. The central cohort preserves a high genetic diversity, and two unique clades of haplotypes were found in the Wamba/Iyondji populations in the central cohort and in the TL2 population in the eastern cohort respectively. This knowledge may contribute to the planning of bonobo conservation.
Subject(s)
DNA, Mitochondrial/genetics , Genetic Variation , Geography , Pan paniscus/genetics , Animals , Animals, Wild/genetics , Congo , Conservation of Natural Resources , Genetics, Population , Haplotypes/genetics , Linear Models , Models, Genetic , Phylogeny , RiversABSTRACT
Seasonal change in time spent for terrestrial behavior of chimpanzees was investigated from the viewpoint of the distribution of food and microclimate in the forest at Bossou, Guinea, West Africa. Daily and monthly data for activity budgets of three focal animals, climatic variables in the forest, and indices of fruit availability and distribution of fruit-bearing trees were estimated and analyzed. Mean activity budgets calculated by monthly means were 23.4% for terrestrial behavior (range, 2.9% in August to 42.1% in November) and 76.6% for arboreal behavior. Chimpanzees spent more time on the ground in warm or dry months. Chimpanzees also spent less time in trees in months with high fruit production (trees of diameter at breast height >/=10 cm). The daily percentage of terrestrial behavior showed a positive correlation with maximum temperature and a negative correlation with the minimum humidity of the day. Only maximum temperature of the observation day influenced time spent on the ground significantly, as analyzed by generalized linear models (GLZ), which included all variables (fruit production, distribution of fruit-bearing trees, and climatic variables). It was concluded that the reason why arboreal behavior increased in the rainy season was not owing to the vertical distribution of food, but rather in order to reduce thermoregulation costs by resting in trees during cool periods and taking advantage of the vertical structure of the microclimate in the tropical forest (i.e., higher temperatures in higher positions).
Subject(s)
Climate , Feeding Behavior , Pan troglodytes , Animals , Behavior, Animal , Female , Male , Seasons , Temperature , Trees , Tropical ClimateABSTRACT
The feeding selection of leaves by chimpanzees was investigated from the perspective of phytochemistry and leaf availability. Field data were collected for 6 months from 1995 to 1996 and 8 months from 1997 to 1998 in Bossou, Guinea. Time budgets of leaf consumption by chimpanzees were analysed and the abundance of young leaves of each tree species for each month was estimated. Analyses of dried materials, stratified by leaf maturity and edibility, for the relative amounts of crude protein, crude fat, neutral detergent fiber, ash, and condensed tannin were determined. It was found that 1) leaves consumed by chimpanzees had higher levels of ash and lower levels of condensed tannin than leaves that were not eaten; 2) feeding selectivity was correlated with crude protein content; and 3) the availability of young leaves was not correlated with the percentage of feeding time, neither by seasonal changes nor by tree species. Chimpanzees preferred leaves containing higher protein content, but did not consume leaves containing high condensed tannin regardless of protein content. It seems reasonable to consider that a different rule exists for "whether chimpanzees eat it or not" and "whether they prefer it or not" in phytochemical determinants of leaves. Some Moraceae species, which had low levels of condensed tannins, even in mature leaves, were an important food source for the Bossou chimpanzees.