My studies of primates: Sex, affinity, and competition

In this essay, I summarize my research career, with reference to the early days of the Laboratory of Physical Anthropology (LPA) at Kyoto University led by Kinji Imanishi and Junichiro Itani. When I started conducting research on the sexual behavior of Japanese macaques in 1975, I made some unexpected observations. High-ranking males did not obtain high mating success. Estrous females often rejected the courtships of high-ranking males and chose to mate with lower-ranking males. Some male-female dyads exhibited long-lasting affinitive relations, but they avoided mating. Females frequently showed 'excessive' sexuality. Clear explanations for some of these observations do not exist. After that, I changed my study subjects several times from chimpanzees, Yakushima macaques (a subspecies of Japanese macaque), and ringtailed lemurs. It is difficult to summarize my findings into a consistent story. Instead, I review my research and experiences. Throughout my career, I kept two things in mind. The first was established by Imanishi at the Laboratory of Physical Anthropology at Kyoto University: to explore the evolution of human society. Second, I tried to understand seemingly incomprehensible phenomena using evolutionary theory. Despite adhering to these foundational concepts, things did not always work out as planned.

Process of Japanese macaque group fission at Arashiyama and the influences of maternal kin relations and social relations between adult males and females on it

In 1986, the Japanese macaques of Arashiyama B group fissioned into Arashiyama E and F groups through the following process. In December 1985, the death of the beta male triggered aggressive interactions among the adult males of B group, leading to a decline in the ranks of two mid-ranked males. Several females started to gather around these two males, formed a stable subgroup (here called the female cluster), and spatially distanced themselves from other group members (main group). Some of these females had mating relations with these two males in previous mating seasons. After the end of the 1985-86 mating season, agonistic interactions occurred frequently between the female cluster and main group. Eventually, two independent groups were established. The females within the 4th degrees of matrilineal consanguinity tended to belong to the same group, but no such tendency occurred in those dyads separated by the 5th or more degrees. After the completion of group fission, mating occurred only a few times between E and F group members. In 1986, when the group fission was in progress, the birth rate of both branch groups declined, and infant mortality increased in E group. After 1987, the birth rate recovered in both branch groups although infant mortality remained high.

Ranging patterns of Japanese macaques in the coniferous forest of Yakushima: Home range shift and travel rate

Ranging is one of the most important behavioral adaptations for coping with seasonally fluctuating food and thermal conditions. We studied the ranging patterns, in particular home range shift and travel rate of Japanese macaques (Macaca fuscata) in the coniferous forest of Yakushima by tracking a group for 17 months. We also supplemented our data with records collected every August over a 5-year annual census. The macaque group used the eastern part of their home range from May to September and the western part during the rest of the year. The eastern part of the home range was largely primary forest in the national park, and the altitude was higher than in the western part. When they used the western part, the macaques ate more herbs and fruits from small-sized trees, the availability of which was higher in the logged forest. This east-west home range shift occurred repeatedly over multiple years. A neighboring group occupied the western part of the focal group's home range in summer, which the focal group did not use in that season. Both temperature and diet affected seasonal changes in the monthly average travel rate. Animals need more energy for thermoregulation when the temperature is low, so the macaques decreased their ranging efforts to save energy at times of low temperature. They increased their ranging distance to eat fungi, since their encounters with this food would increase with the total distance walked. They also increased their travel rate when eating flowers, which had lower food patch (tree) density than other foods such as fruits. The data supported the hypothesis that the macaques capitalize on habitat heterogeneity in a seasonally fluctuating habitat by shifting their home range and modifying their travel rate.

Wild chimpanzees deprived a leopard of its kill: Implications for the origin of hominin confrontational scavenging

This study reports the first observed case of wild chimpanzees (Pan troglodytes) obtaining animal prey freshly killed by a sympatric leopard (Panthera pardus) and scavenging it with the leopard still nearby. This observation has important implications for the emergence of confrontational scavenging, which may have played a significant role in human evolution. Many scholars agree that eating meat became important during human evolution, and hominins first obtained meat by scavenging. However, it is debatable whether scavenging behavior was "passive" or "confrontational (power)." The latter is more dangerous, as it requires facing the original predator, and it is thus considered to have been important for the evolution of several human traits, including cooperation and language. Chimpanzees do scavenge meat, although rarely, but no previous evidence of confrontational scavenging has hitherto emerged. Thus, it was assumed that they are averse to confrontation with even leopard-sized predators. However, in the observed case the chimpanzees frequently emitted waa barks, which indicated that they were aware of the leopard's presence but they nevertheless continued to eat the scavenged meat. In addition, we compiled and reviewed 49 cases of chimpanzee encounters with animal carcasses in the Mahale Mountains of Tanzania in 1980-2017. Chimpanzees scavenged meat in 36.7% of these cases, and tended to eat the meat when it was fresh or if the animal species was usually hunted by chimpanzees. However, no evidence indicated that carcasses were avoided when leopard involvement was likely. These results suggest that chimpanzee-sized hominins could potentially confront and deprive leopard-size carnivores of meat.

Development of new experimental setup focusing on long-pulse magnetic reconnection by using rotating magnetic field technique

A new closed-type experimental setup to achieve a long-pulse magnetic reconnection in weakly ionized plasmas was developed by using a rotating magnetic field (RMF) technique. The experimental setup has a cylindrical vacuum vessel in which two sets of four antennas are equipped to generate RMF which drives steady azimuthal electron current in two torus plasmas. This device provided a quasi-steady magnetic reconnection condition in weakly ionized plasmas with ionization fraction of less than 1%. The proposed experimental setup will extend the research area of laboratory reconnection experiments and be helpful to comprehend the reconnection process in weakly ionized plasmas such as solar chromosphere.

Hormonal contraceptive affects heterosexual but not homosexual behavior in free-ranging female Japanese macaques over 17 mating seasons

We assessed the effect of a progestin-based contraceptive treatment (chlormadinone acetate) on female heterosexual and homosexual behaviors in a free-ranging group of Japanese macaques (Macaca fuscata) living at Arashiyama-Kyoto, Central Japan. The data included estimated intensity of fertility cues, sexual solicitations and mounting behaviors collected daily during 17 consecutive mating seasons (1995-2012) from 159 females. Females that were on contraception: (1) exhibited less intense cues of putative fertility and for shorter periods; (2) were solicited by fewer males, and those males that did solicit them did so less often (i.e., lower heterosexual attractivity); (3) solicited fewer males and when they did perform sexual solicitations they did so less often (i.e., lower heterosexual proceptivity); (4) engaged in shorter heterosexual consortships with fewer male partners (i.e., lower heterosexual receptivity), compared with females that were not on contraception. In contrast, contraceptive treatment had no significant effect on the prevalence, occurrence, frequency, or duration of female homosexual behaviors. Even though heterosexual and homosexual behaviors can both be considered sexual in character and under hormonal control, our results suggested they are, to some extent, dissociable. Because females engaging in homosexual interactions showed less intense cues of putative fertility than those engaging in heterosexual interactions, regardless of contraceptive treatment, we argued that the hormonal threshold required for the expression of heterosexual behavior by females was associated with elevated sex hormones levels compared to homosexual behavior. We discussed the hormonal correlates of sexual behavior and partner preferences in Japanese macaques.

Estudos da instabilidade do íon H2O4+ pelo método CNDO/2

.

Isolation and characterization of microsatellite loci for the large-seeded tree Protorhus deflexa (Anacardiaceae)

PREMISE OF THE STUDY

Protorhus deflexa is an endemic large-seeded tree in Madagascar that depends heavily on insects for cross-pollination and on large-bodied frugivores for seed dispersal. Because such mutualistic relationships are vulnerable to human disturbance, the development of microsatellite markers will enhance analyses of gene flow in this tree species in degraded forests. •

METHODS AND RESULTS

Nineteen microsatellite markers were developed for P. deflexa using 454 pyrosequencing. The number of alleles ranged from two to nine, and the ranges of observed and expected heterozygosities were 0.200-0.800 and 0.303-0.821, respectively. The parentage exclusion probability by the 19 loci reached 0.98583 for the first parent and 0.99971 for the second parent. •

CONCLUSIONS

These markers will be useful for studying gene flow via pollination and seed dispersal by animals and the genetic structure of P. deflexa in protected and degraded forests in Madagascar.

Genetic variation of vascular endothelial growth factor pathway does not correlate with the severity of retinopathy of prematurity

OBJECTIVE

The aim of this study was to assess the genetic effects of the vascular endothelial growth factor (VEGF) pathway on retinopathy of prematurity (ROP).

STUDY DESIGN

A prospective study from a tertiary center that enrolled 204 Japanese infants (<35 weeks of gestational age (GA)) having no anomalies. ROP developed in 127, but not in 77 infants. The relative severity was defined as non-severe, moderate and severe ROP for GA, based on the staging criteria. VEGF (g.-634G>C, g.+13553C>T) and VEGF-receptor (KDR g.+4422(AC)11 to 14, Flt-1 c.+6724(TG)13 to 23) gene polymorphisms and clinical variables were assessed by uni/multivariate analyses.

RESULT

The frequency of polymorphisms did not differ between ROP and non-ROP patients. The TT genotype of g.+13553 showed a higher odds ratio for non-severe ROP than CC genotype (P=0.006). Multivariate analyses indicated that low birth weight, blood transfusion and respiratory distress syndrome, but not polymorphisms, were the risk factors of advanced ROP (≥ stage 3).

CONCLUSION

A genotype of the VEGF pathway weakly affects the severity of ROP compared with other clinical factors.

Congenital multiple pituitary hormone deficiency associated with hyperammonemia: a case report with a short review of the literature

We herein report a case study of a female newborn with multiple pituitary hormone deficiencies who presented with generalized seizures, hypoglycemia and hyperammonemia at 18 h after birth. In addition, we review the association of hyperammonemia in neonates with multiple pituitary hormone deficiencies reported in the previous literature. This unrecognized association should be taken into account for the early diagnosis and treatment of these patients.

Allelic differentiation of Kunitz trypsin inhibitor in wild soybean (Glycine soja)

Soybean Kunitz trypsin inhibitor (SKTI) has several polymorphic types, which are controlled by co-dominant multiple alleles at a single locus. Of these types, Tia and Tib are predominant types, and there are nine differences in amino acids between Tia and Tib. Recently, an intermediate transitional type (Tibi5) between them was detected. However, other transitional types have not been detected despite surveys of many cultivated and wild soybeans. One of the reasons why other transitional variants have not been found is inferred to be due to the difficulty of the detection of SKTI protein variants by polyacrylamide gel electrophoresis (PAGE). To detect novel variants of SKTI, nucleotide sequence analysis in addition to PAGE was carried out. Four new variants were found from many Japanese wild soybeans. Of these variants, three (designated as Tiaa1, Tiaa2, Tiab1) were detected through gene sequence analysis on wild soybeans having the same electrophoretic mobility as Tia, and one (Tig) was detected through PAGE. The Tig variant showed a slightly lower electrophoretic mobility than Tic. The nucleotide sequences of Tig were identical to those of Tib except for one T-->C transitional mutation at position +340. The sequences of Tiaa1 and Tiaa2 genes were identical to those of Tia with the exception of a G-->A mutation at position +376 and a T-->C mutation at +404, respectively. The sequence of Tiab1 differed from Tia by three nucleotides: C-->A at position +331, T-->C at +459 and A-->G at +484. Of the three nucleotide changes, two were common to Tiab1, Tibi5 and Tib, suggesting that Tiab1 is an intermediate transitional type between Tia and Tib. Our results suggest that Tib type has been differentiated through a series of mutations from Tia before the domestication of cultivated soybean.

Food conditions, competitive regime, and female social relationships in Japanese macaques: within-population variation on Yakushima

Feeding conditions, competitive regime, and female social relationships of Japanese macaques (Macaca fuscata) on Yakushima were compared between the two habitats at two different altitudes (coniferous forest, 1,000-1,200 m and coastal forest, 0-200 m). Fruit availability was higher in the coastal forest. There was no consistent difference in the frequency of agonistic interactions within a group during feeding between the two habitats. The coastal forest evoked stronger inter-group contest competition compared to the coniferous forest as evidenced by a higher inter-group encounter rate and a higher proportion of aggressive encounters to non-aggressive ones. Birth rate was higher in larger groups compared to smaller ones in the coastal forest, but did not differ in the coniferous forest. In spite of these differences in competitive regime, no variation in female social relationships was observed, such as direction and concentration on particular individuals in grooming, linearity in dominance rank, counter-attack, and support of juvenile kin during agonistic interactions. The present results indicate that the female social relationships of Japanese macaques are robust and do not change according to changes in the current environment.

Quantitative analysis of Malassezia in the scale of patients with psoriasis using a real-time polymerase chain reaction assay

BACKGROUND

It has been suggested that Malassezia is associated with the development of skin lesions in psoriasis because of the response of the scalp lesions in psoriasis to antifungal agents. Malassezia restricta and M. globosa are the two major members of the cutaneous Malassezia flora in patients with psoriasis, although they have not been analysed quantitatively.

OBJECTIVES

This study quantified the two major cutaneous Malassezia species in psoriatic scale from different body sites using a real-time polymerase chain reaction (PCR) assay.

METHODS

Scale samples were collected from lesional and nonlesional skin of 20 Japanese patients with psoriasis and fungal DNA was extracted from the samples directly. All the Malassezia species, including the two major species M. globosa and M. restricta, were quantified with high accuracy, using a real-time PCR assay.

RESULTS

Colonization by M. restricta was approximately five times higher at all body sites than colonization by M. globosa. Malassezia colonization was significantly lower in patients with hyperlipidaemia than in patients with normolipidaemia.

CONCLUSIONS

Malassezia restricta is the predominant species in psoriatic scale.

Body mass of wild ring-tailed lemurs in Berenty Reserve, Madagascar, with reference to tick infestation: a preliminary analysis

In 1999, we measured the body mass of 101 wild ring-tailed lemurs (Lemur catta) inhabiting the Berenty Reserve, Madagascar. In addition, we counted the number of ticks [Haemaphysalis (Rhipistoma) lemuris Hoogstraal, 1953] infesting their facial skin and external auditory meatuses. For both males and females, the body mass appeared to increase until the age of 3 years. With the apparent exception of infants, there were no sexual differences in body mass. Within a group, higher-ranked adult males tended to be heavier than lower-ranked males. In contrast, there was no consistent correlation between the body mass of females and their ranks. Among the study groups, there was a small difference in body mass and significant difference in the number of ticks infesting the facial skin and external auditory meatuses. In particular, lemurs of a group who inhabited an area of gallery forest in the study area exhibited the smallest values of body mass and were severely infested with ticks. Such group variations were not consistently correlated with the reproductive parameters of the study groups. In three groups moderately infested with ticks, ticks infested adult males and subadults more heavily than adult females, juveniles, and infants.

Influence of group size on reproductive success of female ring-tailed lemurs: distinguishing between IGFC and PFC hypotheses

Based on data obtained over a period of 11 years from female ring-tailed lemurs (Lemur catta), we analyzed the correlation between group size and female reproductive parameters. The birth rate and mean number of surviving infants 1 year after birth per adult female generated an inverted U-shaped curve when plotted against group size (although not significant) and number of adult female members. Infant mortality rate did not have a consistent correlation with group size and number of adult female members. Thus, our findings were similar to the predictions of Wrangham's inter-group feeding competition hypothesis.

Entity evidence for differentiation between Tia and Tib types of soybean Kunitz trypsin inhibitor: detection of a novel transitional variant type between Tia and Tib in wild soybean (Glycine soja Sieb. & Zucc.)

Soybean Kunit trypsin inhibitor (SKTI) has several polymorphic types. Of these SKTI, there are large differences of nine amino acid substitutions between Tia and Tib. So far no transitional type between them has been found. A novel transitional intermediate variant between Tia and Tib was detected in 11 lines from 720 Japanese wild soybeans (Glycine soja Sieb. & Zucc.). This variant showed identical electrophoretic mobility to Tib in the Davis system polyacrylamide gel electrophoresis (PAGE), but higher electric points than other SKTI proteins (Tia, Tib, Tic) in isoelectric focusing PAGE. The genetic analysis of SKTI in F(2) seeds from a cross between the novel variant type and Tib showed that this variant type is inherited as codominant alleles in a multiple allelic system at an SKTI locus. This variant also showed inhibitory activity to trypsin. We propose the genetic symbol Ti b ( i5) for this novel variant. The sequence analysis of Tib ( i5) revealed that six nucleotides were different between Tib ( i5) and Tia, and the nucleotides of these mutated positions were identical to Tib. This causes substitution of five amino acids at the residue position 62 (Tyr-->Phe), 74 (Ser-->Arg), 114 (Met-->Val), 120 (Leu-->Ile) and 137 (Pro-->Thr). These substitutive amino acids are completely in accord with the amino acids of Tib, showing that Tib ( i5) is an intermediate between Tia and Tib types. Tib ( i5) type is widely distributed throughout seven separate areas from northeast to southwest Japan with a 1.5% frequency of total materials examined. This indicated that Tib ( i5) type did not originate from a recent mutation event, but had spread in wild soybean from ancient times.

Comparisons of food availability and group density of Japanese macaques in primary, naturally regenerated, and plantation forests

We compared food availability and group density of Japanese macaques in Yakushima, southern Japan, among primary forest and two habitats that had been disturbed by logging and had different regeneration histories. The study was conducted in an undisturbed national park, forest that was logged 7-18 years ago and later naturally regenerated, and forest that was logged 19-27 years ago and later planted with Japanese cedar (Cryptomeria japonica) trees. The plantation forest was primarily composed of large Cryptomeria japonica trees at low stand density, while the naturally regenerated forest was composed of many small trees. The total basal area and number of trees in the primary forest were comparable to those in the plantation forest. Annual fruit production was greatest in the naturally regenerated forest, intermediate in the primary forest, and negligible in the plantation forest. Herb availability was high in the naturally regenerated forest, but low in the primary and plantation forests. The group density of Japanese macaques was high in the naturally regenerated forest, intermediate in the primary forest, and low in the plantation forest. Since group size in the naturally regenerated forest was small, individual density was almost the same as in the primary forest. These results suggest that the effects of regeneration on macaques vary between the two habitats. The plantation forest consisted mostly of Cryptomeria japonica, which supplies only flowers as food in a limited season, and had a lower density of macaques. On the other hand, in the naturally regenerated forest, fruit production and herb availability were high (probably because of the enhanced light conditions after logging), and the density of macaques was as high as in the primary forest.

Long-term changes in dominance ranks among ring-tailed lemurs at Berenty Reserve, Madagascar

A study was conducted between 1989 and 2001 to monitor changes in the dominance ranks among adult ring-tailed lemurs (Lemur catta) at Berenty Reserve, Madagascar. Adult females were observed to be dominant over adult males. Their rank fluctuated greatly. However, in some troops, female rank orders were fairly stable over a period of several years. In general, male ranks were more unstable than female ranks. Most young females aged 3 years occupied the lowest ranks among adult females. However, several were also observed to have attained relatively higher ranks, placing them right beneath their high-ranking mothers; this suggested the existence of "dependent ranks". Mothers were dominant over their daughters. Similarly, older sisters were usually dominant over younger sisters. The mean duration of alpha status for females was 1.95 years, although considerable variation was observed in the duration of the alpha status (1-5 or more years). Most young males aged 3 years initially occupied the lowest ranks in their natal troops, and then they migrated to non-natal troops around the age of 4 years. They ascended in rank between the ages of 4 and 6 years, although there was considerable variation in the acquirement of high rank. The mean duration of alpha status for males was 2.2 years. Larger males were observed to occupy higher ranks. Occasionally, both males and females showed intense aggression (i.e., targeting aggression) towards others.

Increased serum levels of interferon-gamma-inducible protein 10 and monokine induced by gamma interferon in patients with haemophagocytic lymphohistiocytosis

We measured serum interferon-gamma-inducible protein 10 (IP-10) and monokine induced by gamma interferon (MIG) levels to investigate the role of these molecules in the pathophysiology of haemophagocytic lymphohistiocytosis (HLH). Serum IP-10 and MIG levels were significantly increased in patients with active HLH compared with those of healthy controls. Serum MIG levels decreased gradually during the course of disease in a patient who recovered without therapy. On the other hand, rapid reduction of MIG and IP-10 levels was observed after chemotherapy in a patient with severe HLH. IP-10 and MIG mRNA expression was enhanced in liver and spleen, and IP-10 mRNA expression was enhanced in bone marrow in the patients, suggesting activated macrophages that infiltrated in these organs as one of the main producers of these cytokines. Serum IP-10 and MIG levels showed a significant correlation with serum IFN-gamma levels. In addition, these chemokines had a significant correlation with fever and serum LDH levels, which are clinical indicators of disease activity of HLH. These results suggest that IP-10 and MIG which are produced by activated macrophages by the stimulation of IFN-gamma, play an important role in the pathophysiology of HLH, by recruitment of activated Th1 cells into the tissues or organs.

Detection of interferon-gamma-inducible chemokines in human milk

AIM

To assess the immunological role of human milk by analysing the concentrations of interferon-gamma-inducible protein of 10 kda (IP-10) and monokine induced by interferon-gamma (MIG) in human milk from mothers of preterm and term infants.

METHODS

IP-10 and MIG levels of colostrum, early milk, mature milk and sera were measured by enzyme-linked immunosorbent assay (ELISA). IP-10 and MIG mRNA expression levels in cellular components of human milk were determined by RT-PCR. IP-10 and MIG protein expression in mammary gland tissues was analysed by immunohistochemistry.

RESULTS

Significant amounts of IP-10 and MIG were detected in human milk. The concentrations of IP-10 and MIG in colostrum and early milk were significantly higher than those of sera from healthy controls or lactating mothers. These chemokine concentrations in colostrum and early milk were significantly higher than those of mature milk. Premature delivery or pregnancy complications of mothers had no significant correlation with these chemokine concentrations in breast milk. There were significant correlations between MIG and interferon-gamma (IFN-gamma) or IP-10 levels (p < 0.001) in human milk. Expression of IP-10 and MIG genes and proteins in the milk cells as well as in mammary gland epithelial tissues was detected by RT-PCR and immunohistochemistry.

CONCLUSION

IP-10 and MIG in human milk, probably derived from milk cells and mammary gland epithelial cells, may contribute to the migration and activation of intestinal T lymphocytes to enhance mucosal immunity during the early neonatal period.

New method to census primate groups: estimating group density of Japanese macaques by point census

We devised a new method to estimate the density of primate groups in habitats that preclude the use of a line-transect census because the ground is too steep. We combined point census and group follows. From the number of groups counted at a fixed point for an hour, n, group density D was calculated: D = lambda n / pi. Lambda, the detectability constant, was a constant when distance-dependent detectability g(y) was regressed on a half-normal model: g(y) = e (-lambda y(2)) and can be estimated by combining the information of group follow and point census. Using this method, we estimated the group density of Japanese macaques in Yakushima. A census area of 7 km(2) was divided into 28 grid squares (500 m x 500 m). One observer was positioned at a point in each grid square, and those points were censused simultaneously for 4-6 days from 0600-0700 to 1500-1600 hr. Four troops were followed for 144 hr during the point census. Distance-dependent detectability closely correlated with the half-normal model. The detectability constant varied with the time of day, but it was not influenced by troop identity or topography. Group density was calculated to be 1.48 +/- 0.61 and 0.701 +/- 0.432 groups/km(2) in the disturbed and undisturbed areas, respectively (95% confidence limit). "True" group density estimated by home range data was within the confidence limit calculated by a point census in the home range of the troops for two troops, suggesting that this method was valid. This method is applicable to other species as long as at least one group can be followed, because it satisfies the fundamental assumptions of point census, and the detectability does not seem to be biased by troop or topography.

Population and social dynamics changes in ring-tailed lemur troops at Berenty, Madagascar between 1989 - 1999

In the present study, we recorded all births, immigrations, deaths, and emigrations for a population of ring-tailed lemurs at Berenty Reserve, Madagascar, between September 1989 and August 1999. In September 1989, three troops (C, B, and T) inhabited the study area of 14.2 ha. During the 10-year period, eight troop divisions, six evictions of females, and three troop takeovers of ranges by other troops occurred in and around the study area. Consequently, in August 1999, the number of troops in the same area increased to six (CX, C1, C2A, C2B, T1, and T2). The number of lemurs aged > 1 year increased from 63 to 82, which resulted from 204 births, 58 immigrations, 125 deaths, and 118 emigrations. Of the 204 newborn lemurs during the study period, 103 died, 44 emigrated outside the study area, and 57 remained within the study area. The total number of lemurs that emigrated from natal troops was 69 (54 males and 15 females). Natal males left their troops around the age of 3. Non-natal males changed troops after a tenure varying from 1 to 7 years. Survival curves showed a fall in survival rates of both sexes to < 0.5 between the ages of 2 and 3. For females, the survival rate gradually decreased to < 0.2 at the age of 9. On the other hand, due to emigration, the survival rate of males could not be determined after the age of 5 yr. Since some males attained high-rank at the age of 6 - 10 yr, the prime age for male ring-tailed lemurs is thought to be around 7 - 10 yr. Ring-tailed lemurs are essentially female philopatric, because all cases of females leaving natal troops resulted from troop divisions or forced evictions. Such social changes may have resulted from competition among females. All cases of troop divisions or evictions occurred in larger troops consisting of >or=20 lemurs, and only a few females could rejoin their troops. When males joined such a female-group, a new troop was formed. Although promoted by an increase in population, frequent emigrations of females from original troops are the characteristics of ring-tailed lemurs at Berenty.

Physical growth and retinopathy in preterm infants: involvement of IGF-I and GH

GH and IGF-I are important for physical growth. We measured serum levels of these factors in preterm infants. The study population (n = 81) was divided into three groups according to the gestational age. We evaluated differences in serum GH and IGF-I levels among groups with regard to physical growth and development of retinopathy of prematurity. Serum GH levels in extremely preterm infants born at <28 wk of gestational age were significantly higher than levels in those born between 28 and 34 wk at 1 and 2 mo of age. In contrast, serum IGF-I levels in extremely preterm infants remained low, whereas those in the other two groups gradually increased. Evaluation of the effects of GH and IGF-I on physical growth in very low birth weight infants (<1500 g) showed that IGF-I concentrations were positively related to physical growth for several months after birth, whereas no relationship was observed between GH and physical growth. Multivariate analysis demonstrated that high GH concentration at 1 mo of age was significantly associated with development of severe retinopathy of prematurity. In conclusion, persistent low serum IGF-I levels may explain the slow physical growth during neonatal life, and exposure of high GH may cause, at least in part, severe retinopathy of prematurity in preterm infants.

Highly polymerized procyanidins in brown soybean seed coat with a high radical-scavenging activity

1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of the 70% aqueous acetone extract from the seed coat of the brown soybean variety, Akita-Zairai, was investigated. The activity of the seed coat of Akita-Zairai was much higher than that of three other reddish-brown varieties, but lower than that of two black varieties, and was closely dependent on the content of phenolic compounds. In the LH20 column chromatography of Akita-Zairai, high DPPH radical-scavenging activities were detected in the fractions eluted with MeOH and 70% aqueous acetone. Proanthocyanidins were also detected in fractions showing high radical-scavenging activities. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis showed that the degree of polymerization (DP) of the procyanidins contained in the brown or black soybean seed coat was as high as DP30.

Characterization of expressed genes in the SLL2 region of self-compatible Arabidopsis thaliana

Self-incompatibility in Brassica species is regulated by a set of S-locus genes: SLG, SRK, and SP11/SCR. In the vicinity of the S-locus genes, several expressed genes, SLL2 and SP2/ClpP, etc., were identified in B. campestris. Arabidopsis thaliana is a self-compatible Brassica relative, and its complete genome has been sequenced. From comparison of the genomic sequences between B. campestris and A. thaliana, microsynteny between gene clusters of Arabidopsis and Brassica SLL2 regions was observed, though the S-locus genes, SLG, SRK, and SP11/SCR were not found in the region of Arabidopsis. Almost all genes predicted in this region of Arabidopsis were expressed in both vegetative and reproductive organs, suggesting that the genes in the SLL2 region might not be related to self-incompatibility. Considering the recent speculation that the S-locus genes were translocated as a single unit between Arabidopsis and Brassica, the translocation might have occurred in the region between the SLL2 and SP7 genes.

Starvation survivability of Thermococcus strains isolated from Japanese oil reservoirs

The starvation survivability of seven Thermococcus strains isolated from four Japanese oil reservoirs was compared with that of Thermococcus strains from marine hydrothermal fields. 16S rDNA analyses showed the isolates to be closely related to Thermococcus litoralis. Growth of the isolates was dependent on amino acids, which were present at low concentrations in the oil reservoirs. At 80 degrees C in the formation water, strain CKU-1 from the oil reservoir showed a higher starvation survivability than strain KS-1 from the marine hydrothermal field. Crude oil did not affect the starvation survivability of strain CKU-1, but it reduced that of strain KS-1. These results indicate that strain CKU-1 could survive longer than stain KS-1 under the conditions of an oil reservoir. At 90 degrees C in artificial seawater without organic nutrients, the half-lives of the isolates were between 7.7 and 25.1 days. However, those of the strains from marine hydrothermal fields, except Thermococcus litoralis and Thermococcus chitonophagus, were less than 1.0 day. The higher starvation survivability is probably important for the hyperthermophiles to continue to exist in a hot subterranean oil reservoir where the supply of nutrients seems to be limited.

Thermotoga petrophila sp. nov. and Thermotoga naphthophila sp. nov., two hyperthermophilic bacteria from the Kubiki oil reservoir in Niigata, Japan

Two hyperthermophilic bacteria, strains RKU-1T and RKU-10T, which grew optimally at 80 degrees C, were isolated from the production fluid of the Kubiki oil reservoir in Niigata, Japan. They were strictly anaerobic, rod-shaped fermentative heterotrophs. Based on the presence of an outer sheath-like structure (toga) and 16S rDNA sequences, they were shown to belong to the genus Thermotoga. Cells of strain RKU-1T were 2-7 microm by 0.7-1.0 microm, with flagella. They grew at 47-88 degrees C on yeast extract, peptone, glucose, fructose, ribose, arabinose, sucrose, lactose, maltose, starch and cellulose as sole carbon sources. Cells of strain RKU-10T were 2-7 microm by 0.8-1.2 microm, with flagella. They grew at 48-86 degrees C on yeast extract, peptone, glucose, galactose, fructose, mannitol, ribose, arabinose, sucrose, lactose, maltose and starch as sole carbon sources. While strains RKU-1T and RKU-10T reduced elemental sulfur to hydrogen sulfide, their final cell yields and specific growth rates decreased in the presence of elemental sulfur. Thiosulfate also inhibited growth of strain RKU-1T but not strain RKU-10T. The G+C contents of the DNA from strains RKU-1T and RKU-10T were 46.8 and 46.1 mol%. Phenotypic characteristics and 165 rDNA sequences of the isolates were similar to those of Thermotoga maritima and Thermotoga neapolitana, both being hyperthermophilic bacteria isolated from hydrothermal fields. However, the isolates differed from these species in their minimum growth temperatures, utilization of some sugars, sensitivity to rifampicin and the effects of elemental sulfur and thiosulfate on growth. The low levels (less than 31%) of DNA reassociation between any two of these hyperthermophilic Thermotoga strains indicated that the isolates were novel species. Analysis of the gyrB gene sequences supported the view that the isolates were genotypically different from these reference species. The isolates were named Thermotoga petrophila sp. nov., with type strain RKU-1T (= DSM 13995T = JCM 10881T), and Thermotoga naphthophila sp. nov., with type strain RKU-10T (= DSM 13996T = JCM 10882T).

Interleukin-18 in human milk

We analyzed IL-18 levels of human milk. Colostrum contained significantly higher levels of IL-18 compared with early milk and mature milk. By stepwise multiple linear regression analysis, preterm delivery and pregnancy complications of mothers significantly correlated with high levels of IL-18 in human milk (p = 0.0007 and 0.0018, respectively). There was a significant correlation between the levels of IL-18 and soluble Fas ligand in colostrum (p = 0.0003). IL-18 was detected in actively secreting epithelial cells in lactating mammary gland by immunohistochemical staining. These results suggest that IL-18 in colostrum plays an important role in host defense of high-risk neonates.

Epstein-Barr virus (EBV) load and cytokine gene expression in activated T cells of chronic active EBV infection

To identify the role of T cells in chronic active Epstein-Barr virus (EBV) infection, EBV and cytokine gene expression was quantified by use of real-time polymerase chain reaction (PCR) among 6 patients who fulfilled the diagnostic criteria for chronic active EBV infection. Four of these patients showed clonal expansion of EBV-infected T cells. Quantitative PCR for EBV DNA in peripheral blood of patients with symptomatic chronic active EBV infection showed higher copy numbers of virus (mean, 1.45 x 10(5) copies/mL) than were seen in blood from patients with infectious mononucleosis (3.08 x 10(3) copies/mL) or with EBV-associated hemophagocytosis (2.95 x 10(4) copies/mL). Fractionated CD3(+) HLA-DR(+) cells from patients with chronic active EBV infection contained higher copy numbers than did CD3(+) HLA-DR(-) cells. Quantitative PCR for cytokines revealed that interferon-gamma, interleukin (IL)-2, IL-10, and transforming growth factor-beta genes were expressed at higher levels in HLA-DR(+) than in HLA-DR(-) T cells. These results suggest that activated T cells in chronic active EBV infection expressed high levels of EBV DNA and both Th1 and Th2 cytokines. EBV-infected T cells may contribute to the unbalanced cytokine profiles of chronic mononucleosis.

Immunophenotypic and functional characterization of CD33(+)CD34(+) cells in human cord blood of preterm neonates

OBJECTIVE

To characterize CD33(+)CD34(+) cells, a major population in human cord blood (CB) CD34(+) cells of preterm neonates.

MATERIALS

The proportion of CD33(+) cells was analyzed on CB CD34(+) cells from preterm and full-term neonates. CD33(+)CD34(+) cells were purified by cell sorting and analyzed on their clonogenic activity, proliferative activity in short-time liquid suspension culture, and GATA-2 mRNA expression by RT-PCR and Southern blot.

RESULTS

The absolute numbers and proportion of CD34(+) cells in mononuclear cells inversely correlated with gestational age. CD33 was expressed on a majority of CB CD34(+) cells of preterm neonates but on only a minor population of them in full-term neonates. In addition, CD33 was dominantly expressed on CD38(-)CD34(+) cells or CD117(low)CD34(+) cells in CB of preterm neonates. CD33(+)CD34(+) cells of preterm cord blood had high proliferative and reproducible potentials compared with CD33(-)CD34(+) cells. CD33(+)CD34(+) cells as well as CD33(-)CD34(+) cells from preterm CB highly expressed GATA-2, in contrast to those from BM.

CONCLUSIONS

These results suggest that CD33(+)CD34(+) cells, which are a major population in CB CD34(+) cells of preterm neonates, do not simply represent relatively mature myeloid lineage hematopoietic progenitor cells as those in adult BM CD34(+) cells, and may contain hematopoietic stem cells or primitive progenitor cells as in fetal liver.

Analysis of expressed sequence tags of flower buds in Lotus japonicus

In order to study gene expression in a reproductive organ, we constructed a cDNA library of mature flower buds in Lotus japonicus, and characterized expressed sequence tags (ESTs) of 842 clones randomly selected. The EST sequences were clustered into 718 non-redundant groups. From BLAST and FASTA search analyses of both protein and DNA databases, 58.5% of the EST groups showed significant sequence similarities to known genes. Several genes encoding these EST clones were identified as pollen-specific genes, such as pectin methylesterase, ascorbate oxidase, and polygalacturonase, and as homologous genes involved in pollen-pistil interaction. Comparison of these EST sequences with those derived from the whole plant of L. japonicus, revealed that 64.8% of EST sequences from the flower buds were not found in EST sequences of the whole plant. Taken together, the EST data from flower buds generated in this study is useful in dissecting gene expression in floral organ of L. japonicus.

Highly divergent sequences of the pollen self-incompatibility (S) gene in class-I S haplotypes of Brassica campestris (syn. rapa) L

Self-incompatibility (SI) enables flowering plants to discriminate between self- and non-self-pollen. In Brassica, SI is controlled by the highly polymorphic S locus. The recently identified male determinant, termed SP11 or SCR, is thought to be the ligand of S receptor kinase, the female determinant. To examine functional and evolutionary properties of SP11, we cloned 14 alleles from class-I S haplotypes of Brassica campestris and carried out sequence analyses. The sequences of mature SP11 proteins are highly divergent, except for the presence of conserved cysteines. The phylogenetic trees suggest possible co-evolution of the genes encoding the male and female determinants.

Agrobacterium-mediated transformation of cotyledonary explants of Chinese cabbage (Brassica campestris L. ssp. pekinensis)

 A procedure for producing transgenic Chinese cabbage plants by inoculating cotyledonary explants with Agrobacterium tumefaciens strain EHA101 carrying a binary vector pIG121Hm, which contains kanamycin-resistance and hygromycin-resistance genes and the GUS reporter gene, is described. Infection was most effective (highest infection frequency) when explants were infected with Agrobacterium for 15 min and co-cultivated for 3 days in co-cultivation medium at pH 5.2 supplemented with 10 mg/l acetosyringone. Transgenic plants of all three cultivars used were obtained with frequencies of 1.6-2.7% when the explants were regenerated in shoot regeneration medium solidified with 1.6% agar. A histochemical GUS assay and PCR and Southern blot analyses confirmed that transformation had occurred. Genetic analysis of T1 progeny showed that the transgenes were inherited in a Mendelian fashion.

Impact of elevated cytosolic and apoplastic invertase activity on carbon metabolism during potato tuber development

During tuberization in Solanum tuberosum var. Desirée maximal catalytic activities of invertase(s) and sucrose synthase are inversely correlated. During the early stages, invertase activity is high and declines during maturation. The decrease in invertase activity is accompanied by a decrease in the hexose to sucrose ratio and an increase in sucrose synthase activity. This switch is paralleled by the onset of the storage phase as shown by the accumulation of starch and storage proteins. Biochemical and genetic evidence suggests that sucrose synthase activity is positively correlated with sink strength. To explore the possibility of enhancing sink strength in potato tubers by elevating the sucrolytic capacity, transgenic potato plants expressing either cytosolic or apoplastic yeast invertase in their tubers were made. Surprisingly, cytosolic invertase led to a decrease and apoplastic invertase to an increase in tuber yield. To understand the causes of the observed phenotypes, carbon metabolism in tubers of transgenic and control plants was analysed during different stages of tuber development. Both cytosolic and apoplastic invertase resulted in decreased sucrose and elevated glucose contents, indicating that sucrose is accessible in both compartments. Metabolic perturbation, however, was found to be compartment specific. Elevated cytosolic invertase activity led to increased carbon flux towards glycolysis and accumulation of phosphorylated intermediates. The phosphorylated intermediates were not used to build up starch. In contrast, apoplastic invertase does not lead to a significant increase in hexose phosphates compared to untransformed controls. Thus, hexoses originating in the apoplast are not efficiently phosphorylated during potato tuber development, which might be explained by an endocytotic uptake of sucrose and/or hexoses from the apoplast into the vacuole bypassing the cytosolic compartment.

QSAR and molecular graphics analysis of N2-phenylguanines as inhibitors of herpes simplex virus thymidine kinases

A quantitative structure-activity relationship study of N2-(substituted)-phenylguanines (PHG) as inhibitors of herpes simplex virus thymidine kinase (HSV TK) was performed. The activity of a set of PHG derivatives were analyzed against the thymidine kinase of herpes simplex virus types 1 (HSV1 TK) and 2 (HSV2 TK). Classic and calculated physicochemical parameters were included in the analysis. The results showed that there is an important difference in the activity of the meta substituted PHG derivatives against HSV1 TK and HSV2 TK. The activity of the meta derivatives against HSV2 TK is influenced by a steric effect, which is not observed against HSV1 TK. The superposition of the three-dimensional structures of the active sites of HSV1 TK (crystal structure) and HSV2 TK (homology model) revealed that the amino acid Ile97 is located near the meta position in the HSV1 TK active site, whereas the amino acid Leu97 is located near the meta position in the HSV2 TK active site. This single difference in the active sites of both enzymes can explain the source of the steric effect and serves as an indication that our previously proposed binding mode for the PHG derivatives is plausible. However, another observed mutation in the active site region, Ala168 by Ser168, suggests that an alternative binding mode, similar to that of ganciclovir, could be possible.

Distribution and physiological characteristics of hyperthermophiles in the Kubiki oil reservoir in Niigata, Japan

The distribution of culturable hyperthermophiles was studied in relation to environmental conditions in the Kubiki oil reservoir in Japan, where the temperature was between 50 and 58 degrees C. Dominant hyperthermophilic cocci and rods were isolated and shown to belong to the genera Thermococcus and Thermotoga, respectively, by 16S rDNA analyses. Using the most-probable-number method, we found that hyperthermophilic cocci were widely distributed in several unconnected fault blocks in the Kubiki oil reservoir. In 1996 to 1997, their populations in the production waters from oil wells were 9.2 x 10(3) to 4.6 x 10(4) cells/ml, or 10 to 42% of total cocci. On the other hand, hyperthermophilic rods were found in only one fault block of the reservoir with populations less than 10 cells/ml. Dominant Thermococcus and Thermotoga spp. grew at reservoir temperatures and utilized amino acids and sugars, respectively, as sole carbon sources. While organic carbon was plentiful in the environment, these hyperthermophiles were unable to grow in the formation water due to lack of essential nutrients. Concentrations of some organic and inorganic substances differed among fault blocks, indicating that the movement of formation water between fault blocks was restricted. This finding suggests that the supply of nutrients via fluid current is limited in this subterranean environment and that the organisms are starved in the oil reservoir. Under starved conditions at 50 degrees C, culturable cells of Thermococcus sp. remained around the initial cell density for about 200 days, while those of Thermotoga sp. decreased exponentially to 0. 01% of the initial cell density after incubation for the same period. The difference in survivability between these two hyperthermophiles seems to reflect their populations in the fault blocks. These results indicate that hyperthermophilic cocci and rods adapt to the subterranean environment of the Kubiki oil reservoir by developing an ability to survive under starved conditions.

Regulation of carbohydrate partitioning during the interaction of potato virus Y with tobacco

Abstract To test whether carbohydrates may play a signalling function during plant pathogenesis, we investigated the interaction between tobacco and potato virus Y (PVY(N)). Four days after PVY(N) infection, leaves started to accumulate soluble sugars and leaf photosynthesis decreased. The accumulation of soluble sugars was accompanied by an induction of cell wall invertase and a gradual decrease in the sucrose-to-hexose ratio. In parallel to changes in carbohydrate metabolism and photosynthesis, transcripts encoding PR-proteins accumulated. Based on this coincidence, it was hypothesized that elevated hexose levels may enhance the expression of defence-related functions and might possibly explain the phenomenon of high sugar resistance in plants. This notion has been supported by the fact that cell wall invertase-expressing transgenic tobacco plants were found to be resistant against PVY(N) (Herbers et al., 1996b). To exclude the possibility that salicylate, which accumulates in plants expressing invertase, may be responsible for the observed resistance, these transgenic plants were crossed with salicylate hydroxylase-expressing plants (nahG). The progeny were selected for high levels of sugar and low levels of salicylate. Necrotic lesions also developed, typically formed on the leaves of plants expressing invertase, and transcripts encoding PR-Q accumulated in the absence of salicylate. On the other hand, accumulation of PR-1b transcripts decreased, indicating that sugars are not sufficient for PR-1b induction. Infection experiments using these plants as hosts revealed resistance towards PVY(N). Thus, the mechanism of apoplastic invertase induced virus resistance is salicylate independent and most likely sugar mediated.

Structure-activity relationship studies of carcinogenic activity of polycyclic aromatic hydrocarbons using calculated molecular descriptors with principal component analysis and neural network methods

Recently a new methodology based on local density of state (LDOS) calculations using topological and semiempirical methods was proposed to identify the carcinogenic activity of polycyclic aromatic hydrocarbons (PAHs). In this work we perform a comparative study of this methodology with principal component analysis (PCA) and neural networks (NN). The PCA and NN results show that LDOS quantum chemical descriptors are relevant descriptors to identify the carcinogenic activity of methylated and non-methylated PAHs. Also, we show that the combination of these distinct methodologies can be an efficient and powerful tool in the structure-activity studies of PAHs compounds. We have studied 81 methylated and non-methylated PAHs, and our study shows that with the use of these methods it is possible to correctly predict the carcinogenic activity of PAHs with accuracy higher than 80%.