Timing and distance of natal dispersal in Asian black bears

Dispersal has important implications for population ecology and genetics of a species through redistribution of individuals. In most mammals, males leave their natal area before they reach sexual maturity, whereas females are commonly philopatric. Here, we investigate the patterns of natal dispersal in the Asian black bear (Ursus thibetanus) based on data from 550 bears (378 males, 172 females) captured or removed in Gunma and Tochigi prefectures on central Honshu Island, Japan in 2003–2018. We used genetic data and parentage analysis to investigate sex-biased differences in the distance of natal dispersal. We further investigated the age of dispersal using spatial autocorrelation analysis, that is, the change in the correlation between genetic and geographic distances in each sex and age group. Our results revealed that male dispersal distances (mean ± SE = 17.4 ± 3.5 km) were significantly farther than female distances (4.8 ± 1.7 km), and the results were not affected by years of mast failures, a prominent forage source for this population. Based on an average adult female home range radius of 1.8 km, 96% of the males and 50% of the females dispersed. In the spatial autocorrelation analysis, the changes in the relationship between genetic and geographic distances were more pronounced in males compared to females. Males seem to mostly disperse at age 3 regardless of mast productivity, and they gradually disperse far from their home range, but young and inexperienced males may return to their natal home range in years with poor food conditions. The results suggest that factors driving the dispersal process seem to be population structure-based instead of forage availability-based. In females, a significant genetic relationship was observed among all individuals in the group with a minimum age of 6 years within a distance of 2 km, which resulted in the formation of matrilineal assemblages.

Comparing information derived on food habits of a terrestrial carnivore between animal-borne video systems and fecal analyses methods

In recent years, animal-borne video cameras have been used to identify the food habits of many species. However, the usefulness and difficulties of identifying food habits from animal-borne video cameras have not been sufficiently discussed in terrestrial mammals, especially large omnivores. The aim of this study is to compare the video analysis of foraging behavior by Asian black bears (Ursus thibetanus) acquired by camera collars with estimates from fecal analysis. We attached GPS collars equipped with video cameras to four adult Asian black bears in the Okutama mountains in central Japan from May to July 2018 and analyzed video clips for foraging behavior. Simultaneously, we collected bear feces in the same area to determine food habits. We found that using video analyses was advantageous to recognize foods, such as leaves or mammals, that were physically crushed or destroyed while bears chewed and digested foods, which are difficult to identify to species using fecal analyses. On the other hand, we found that camera collars are less likely to record food items that are infrequently or quickly ingested. Additionally, food items with a low frequency of occurrence and short foraging time per feeding were less likely to be detected when we increased the time between recorded clips. As one of the first applications of the video analysis method for bears, our study shows that video analysis can be an important method for revealing individual differences in diet. Although video analysis may have limitations for understanding the general foraging behavior of Asian black bears at the present stage, the accuracy of food habit data from camera collars can be improved by using it in combination with established techniques such as microscale behavior analyses.

Functional traits driving species role in the structure of terrestrial vertebrate scavenger networks

Species assemblages often have a non-random nested organization, which in vertebrate scavenger (carrion-consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and others are facultative, scavenging opportunistically. We used a database with 177 vertebrate scavenger species from 53 assemblages in 22 countries across five continents to identify which functional traits of scavenger species are key to maintaining the scavenging network structure. We used network analyses to relate ten traits hypothesized to affect assemblage structure with the "role" of each species in the scavenging assemblage in which it appeared. We characterized the role of a species in terms of both the proportion of monitored carcasses on which that species scavenged, or scavenging breadth (i.e., the species "normalized degree"), and the role of that species in the nested structure of the assemblage (i.e., the species "paired nested degree"), therefore identifying possible facilitative interactions among species. We found that species with high olfactory acuity, social foragers, and obligate scavengers had the widest scavenging breadth. We also found that social foragers had a large paired nested degree in scavenger assemblages, probably because their presence is easier to detect by other species to signal carcass occurrence. Our study highlights differences in the functional roles of scavenger species and can be used to identify key species for targeted conservation to maintain the ecological function of scavenger assemblages.

Animal-borne video systems provide insight into the reproductive behavior of the Asian black bear

Previous studies on the mating system of the Asian black bear (Ursus thibetanus) have been limited to observations of captive populations and estimations of multiple paternities. Hence, the mating system of wild bears remains poorly understood. Animal-borne camera systems (i.e., cameras mounted on animals) provide novel tools to study the behavior of elusive animals. Here, we used an animal-borne video system to record the activities of wild bears during the mating season. Video camera collars were attached to four adult Asian black bears (male "A" and "B," and female "A" and "B") captured in Tokyo, central Japan, in May and June 2018. The collars were retrieved in July 2018, after which the video data were downloaded and analyzed in terms of bear activity and mating behavior. All the bears were found to interact with other uniquely identifiable bears for some of the time (range 9-22 days) during the deployment period (range 36-45 days), and multiple mating in males was documented. Both males and females exhibited different behaviors on social days (i.e., days when the bear interacted with conspecifics) compared with solitary days (i.e., days with no observed interactions with conspecifics). Compared with solitary days, the bears spent a lower proportion of time on foraging activities and higher proportion of time on resting activities on social days. Our results suggest that Asian black bears have a polygamous mating system, as both sexes consort and potentially mate with multiple partners during a given mating season. Furthermore, bears appeared to reduce their foraging activities on social days and engaged more in social interactions.

Vertebrate scavenger guild composition and utilization of carrion in an East Asian temperate forest

Scavenging is a common feeding behavior by many species that plays an important role in ecosystem stability and function while also providing ecosystem services. Despite its importance, facultative scavenging on large animal carcasses has generally been overlooked in Asian temperate forest ecosystems. The aim of this study was to determine the composition and feeding behavior of the facultative scavenger guild as it relates to sika deer (Cervus nippon) carcasses in Japanese forests. There are no obligate scavengers or large predators that kill adult ungulates, but humans fill the role of large predators by culling deer for population management. We documented nine vertebrate species scavenging on deer carcasses and found that mammals were more frequent scavengers than birds and also fed for longer durations. This result suggests that there is a facultative scavenger guild composed mainly of mammals in our forest ecosystem and that carcass utilization by birds was restricted to only forest species. Raccoon dogs (Nyctereutes procyonoides) and Asian black bears (Ursus thibetanus) were the most frequent scavenger species and also fed for longer durations than other scavengers. There were significant seasonal differences in scavenging by Asian black bear, Japanese marten (Martes melampus), and mountain hawk-eagle (Nisaetus nipalensis), suggesting the availability of other food resources may alter facultative scavenging by each species. Our results support that scavenging is widespread in this system and likely has important functions including building links in the food web.

Does hard mast production affect patterns of cementum annuli formation in premolar teeth of Asian black bears (Ursus thibetanus)?

Cementum annuli widths in mammals are is influenced by the nutrition of mammals. Reproductive stress has been is suggested to reduce the width of lead to narrower cementum annuli widths in female Asian black bears (Ursus thibetanus); however, food availability in autumn strongly impacts bear nutrition and likely impacts cementum widths as well. This study aimed to test how cementum annuli widths and the formation of false annuli were influenced by hard mast production. We established two hypotheses: (1) cementum annuli widths become narrower in poor mast years owing to inadequate nutritional conditions and (2) false annuli occur more frequently in poor mast years. We used teeth samples from male bears to avoid reproductive influences and separated width data into "adult" and "subadult" groups. We calculated the proportional width index (PWI) and used linear mixed models to estimate the masting effects on PWI. Generalized linear mixed models estimated the masting effects on false annuli frequency. True annuli widths and false annuli formation showed no significant relationship with mast production in adults. In subadults, poor mast production weak negative influence on false annuli formation. These new data resolve previous questions, allowing us to deduce that cementum annuli widths are a reliable index of reproductive success in female bears.

The influence of collagen III expression on the efficiency of cell isolation with the use of collagenase H

OBJECTIVE

We previously demonstrated that collagenase H (ColH) plays a crucial role in rat islet isolation, whereas collagenase G (ColG) plays only a supporting role. We also showed that collagen III appears to be one of the key targets of ColH based on a mass spectrometry analysis. In the present study, we investigated whether our novel findings in an islet isolation model are universally applicable for other types of cell isolation, such as a hepatocyte isolation, with the use of enzyme blends of recombinant collagenases.

METHODS

As the first step, the expression of one of the main matrix components, collagen III, on rat pancreatic and hepatic tissues was assessed with the use of immunohistochemical staining. ColG and ColH were expressed in recombinant E. coli carrying expression plasmids for each collagenase. Then the efficiency of the collagenase subtype on rat hepatocyte isolation was evaluated in terms of cell yield with the use of thermolysin combined with either ColG or ColH (n = 3, respectively).

RESULTS

The expression of collagen III on rat hepatic tissues was dramatically lower than that of rat pancreatic tissues. In the rat hepatocyte isolation, a substantial amount of hepatocytes (0.81 ± 0.11 × 10(6)) were obtained in the ColG group, whereas almost no hepatocytes were retrieved in the ColH group, indicating that the influence of the collagenase subtypes in rat hepatocyte isolation are completely opposite to that observed in rat islet isolation.

CONCLUSIONS

Considering that the expression of collagen III on hepatic tissues was relatively low and that almost no hepatocytes were retrieved when ColH and thermolysin were used, the present study supports our novel finding that collagen III appears to be one of the key targets of ColH in hepatocyte isolation. Therefore, the semiquantification of collagen III on the target tissues not only may positively contribute to efficient islet isolation, but also may affect other types of cell isolation by optimizing the ColH amount.

Visible-light-controlled homo- and copolymerization of styrenes by a bichromophoric Ir–Pd catalyst

Visible-light-controlled polymerization was achieved by a bichromophoric organopalladium catalyst which possesses a naphthyl-substituted cyclometallated Ir(iii) light-absorbing moiety.

Contribution of fetal ANXA5 gene promoter polymorphisms to the onset of pre-eclampsia

OBJECTIVE

A common haplotype M2 consisting of minor SNP alleles located in the ANXA5 gene promoter region has been described as a risk factor for various obstetric complications such as recurrent pregnancy loss, pre-eclampsia and pregnancy-related thrombophilic disorder. However, the question of whether it is the maternal or fetal genotype that contributes to the onset of these disorders remains to be resolved.

METHODS

We analyzed ANXA5 gene variants in the blood and placental tissues from pre-eclampsia patients and normotensive controls. ANXA5 expression was examined by qRT-PCR, Western blotting and immunostaining. Results were compared between M2 and non-M2 carriers.

RESULTS

The M2 haplotype was found to be significantly frequent in placentas from pre-eclamptic patients relative to the controls (25.5% versus 10%, P = 0.044), In contrast, no significant differences were observed in maternal blood (13.0% versus 11.3%, P = 0.597). The placental expression of ANXA5 mRNA was found to be lower in M2 carriers. When examined by Western blot and immunostaining, the ANXA5 protein levels were found to be affected more by the placental than the maternal genotype. Histological examination of the placentas from the pre-eclamptic patients demonstrated that a placental M2 haplotype correlated more closely than maternal M2 with the severity of perivillous fibrin deposition.

CONCLUSIONS

Although preliminary, these results suggest that hypomorphic M2 alleles in the in placental ANXA5 promoter, whether transmitted maternally or paternally, might be an essential determinant of an increased risk of pre-eclampsia via local thrombophilia at the feto-maternal interface.

Upregulation of HtrA4 in the placentas of patients with severe pre-eclampsia

High temperature requirement A (HtrA) family proteins are serine proteases that may serve in the quality control of misfolded or mislocalized proteins. Recently, possible involvements of HtrA1 in the normal development of the placenta and in the pathogenesis of pre-eclampsia were reported. In this study, we characterized HtrA4, a previously uncharacterized HtrA protein family member, in pre-eclampsia. Elevated expression levels of placental HtrA4 in pre-eclampsia patients were observed by qRT-PCR. Western blotting also showed an increased production of HtrA4 at the protein level in pre-eclamptic placentas. In normal chorionic villi, HtrA4 protein was more abundant in the cytoplasm of cytotrophoblasts than in syncytiotrophoblasts. In contrast, the amount of HtrA4 protein in syncytiotrophoblasts was dramatically increased in pre-eclamptic placentas. Circulating HtrA4 was detected at higher levels in sera from women with pre-eclampsia than from those with normotensive pregnancies. Serum HtrA4 levels were higher in patients with early onset and inversely correlated with the weights of the newborn and placenta. Furthermore, serum levels correlated with serum PAPP-A and PAPP-A2 levels, indicating a functional role for HtrA4 in the common pathway. These data suggest that increased HtrA4 may be involved in the onset of pre-eclampsia, and elevated levels in sera imply a potential application as a biomarker for this disorder.

The impact of ischemic stress on the quality of isolated pancreatic islets

BACKGROUND

Although the ischemic stress of donated organs has been shown to have strong negative effects on islet recovery, the impact on islet quality remains uncertain. In the present study, therefore, we examined the influence of ischemic stress on the expression of inflammatory mediators among isolated islets.

MATERIALS AND METHODS

Islets were isolated from adult porcine pancreata subjected to 16-hour cold ischemia time (CIT) in addition to 40-minute warm ischemia time (WIT). We evaluated the islet yield, islet loss during the first 24 hours in culture, adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio, ATP/DNA ratio, glucose-stimulated respiratory activity, in vivo bioassay, and the expression of inflammatory mediators (tissue factor [TF], [MCP-1], macrophage migration inhibitory factor) on the isolated islets. We also analyzed ATP/DNA ratios of the exocrine tissues during isolation procedures.

RESULTS

The islet yield, survival rate during culture, and glucose-stimulated respiratory activity were significantly lower in cases of 16-hour CIT plus 40-minute WIT compared with the control group (P < .0001, .0006, and .002, respectively). In contrast, ADP/ATP ratio as well as TF and MCP-1 expressions on the isolated islets were higher among the ischemic group (P = .005, .16, and .005, respectively). During isolation procedures, the ATP/DNA of the exocrine tissues was extremely lower in the ischemic compared to the control group (P < .0001). Notably, however, both ATP/DNA and ADP/ATP ratio of isolated islets were well preserved even in the ischemic group (P = .45 and .40).

DISCUSSION

These data suggest that ischemic stress during the preservation period negatively affects the energy status of exocrine tissues. Destruction of the exocrine tissues, in combination with warm ischemic stress during the isolation procedures, subsequently decreases isolated islet activity, inducing the expression of inflammatory mediators.

Bortezomib-resistant myeloma cell lines: a role for mutated PSMB5 in preventing the accumulation of unfolded proteins and fatal ER stress

Bortezomib is an effective agent for treating multiple myeloma (MM). To investigate the underlying mechanisms associated with acquired resistance to this agent, we established two bortezomib-resistant MM cell lines, KMS-11/BTZ and OPM-2/BTZ, the 50% inhibitory concentration values of which were respectively 24.7- and 16.6-fold higher than their parental cell lines. No activation of caspase and BH3-only proteins such as Noxa was noted in bortezomib-resistant cells after exposure to the drug. The accumulation of polyubiquitinated proteins was reduced in bortezomib-resistant cells compared with the parental cells, associated with avoidance of catastrophic ER stress as assessed by downregulation of CHOP expression. These resistant MM cells have a unique point mutation, G322A, in the gene encoding the proteasome beta5 subunit (PSMB5), likely resulting in conformational changes to the bortezomib-binding pocket of this subunit. KMS-11 parental cells transfected to express mutated PSMB5 also showed reduced bortezomib-induced apoptosis compared with those expressing wild-type PSMB5 or the parental cells. Expression of mutated PSMB5 was associated with the prevention of the accumulation of unfolded proteins. Thus, a fraction of MM cells may acquire bortezomib resistance by suppressing apoptotic signals through the inhibition of unfolded protein accumulation and subsequent excessive ER stress by a mutation of the PSMB5 gene.

The CCR4 as a novel-specific molecular target for immunotherapy in Hodgkin lymphoma

Here, we report that tumor cells from some patients (23.8%) with Hodgkin lymphoma (HL) are positive for CC chemokine receptor 4 (CCR4). We therefore tested the chimeric anti-CCR4 monoclonal antibody (mAb), KM2760, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity (ADCC), as a novel immunotherapy for refractory HL. KM2760 demonstrated a promising antitumor activity in the CCR4-positive HL-bearing mouse model in the therapeutic setting. Although KM2760 did not induce any ADCC mediated by mouse natural killer (NK) cells, it significantly enhanced phagocytosis mediated by mouse monocytes/macrophages against the CCR4-positive HL cell line in vitro. Together with the findings that KM2760 did not exhibit any complement-dependent cytotoxicity or direct antiproliferation activity in vitro, these data indicated that KM2760 exerted its robust in vivo antitumor activity via monocytes/macrophages in mice. In the human system, KM2760 enhanced phagocytic activity mediated by monocytes/macrophages. Furthermore, it induced robust ADCC mediated by NK cells against the CCR4-positive HL cell line in vitro. Thus, it is conceivable that KM2760 would have much more potent antitumor activity in humans than in mice. Collectively, this study strongly indicates that anti-CCR4 mAb could be a novel treatment modality for patients with CCR4-positive HL.

The CCR4 as a novel-specific molecular target for immunotherapy in Hodgkin lymphoma

Here, we report that tumor cells from some patients (23.8%) with Hodgkin lymphoma (HL) are positive for CC chemokine receptor 4 (CCR4). We therefore tested the chimeric anti-CCR4 monoclonal antibody (mAb), KM2760, the Fc region of which is defucosylated to enhance antibody-dependent cellular cytotoxicity (ADCC), as a novel immunotherapy for refractory HL. KM2760 demonstrated a promising antitumor activity in the CCR4-positive HL-bearing mouse model in the therapeutic setting. Although KM2760 did not induce any ADCC mediated by mouse natural killer (NK) cells, it significantly enhanced phagocytosis mediated by mouse monocytes/macrophages against the CCR4-positive HL cell line in vitro. Together with the findings that KM2760 did not exhibit any complement-dependent cytotoxicity or direct antiproliferation activity in vitro, these data indicated that KM2760 exerted its robust in vivo antitumor activity via monocytes/macrophages in mice. In the human system, KM2760 enhanced phagocytic activity mediated by monocytes/macrophages. Furthermore, it induced robust ADCC mediated by NK cells against the CCR4-positive HL cell line in vitro. Thus, it is conceivable that KM2760 would have much more potent antitumor activity in humans than in mice. Collectively, this study strongly indicates that anti-CCR4 mAb could be a novel treatment modality for patients with CCR4-positive HL.

Positron emission tomography and magnetic resonance imaging in spinocerebellar ataxia type 2: a study of symptomatic and asymptomatic individuals

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant neurodegenerative disorder characterized as an expanded CAG trinucleotide repeats in SCA2 gene resulting in abnormal polyglutamine sequence. We used positron emission tomography (PET) and magnetic resonance imaging (MRI) to clarify metabolic and atrophic changes of the brain in two symptomatic and three asymptomatic individuals who were genetically confirmed for SCA2. PET revealed decreased glucose metabolism in both patients and two of the three asymptomatic carriers in the cerebellum, pons, or both. No PET abnormality was found in the remaining one carrier who had only a very mildly expanded CAG repeat. MRI showed cerebellar and/or pontine atrophic changes in both patients and one of three carriers. The present study suggest that hypometabolism and atrophy of the cerebellum and pons may occur years before the clinical onset of SCA2. PET and MRI may be useful in the early detection of subclinical brain changes associated with SCA2.

Detecting Human CD34 + and CD34 - Hematopoietic Stem and Progenitor Cells Using a Sysmex Automated Hematology Analyzer

In clinical medicine, particularly in the newly developing stem cell therapies required to support the practice of regenerative medicine, the measurement of both CD34+ and CD34- hematopoietic stem cells (HSC)/hematopoietic progenitor cells (HPC) is important in obtaining more accurate information about the total HSC/HPC content in various stem/progenitor cell sources. We report the results of an investigation into methods of detecting CD34+ and CD34- HSC/HPC using the immature information (IMI) channel incorporated into the Sysmex XE-2100 and SE-9000 automated hematology analyzers. In this study, CD34+ and CD34- HSC/HPC were separated by immunologic methods and quantified by flow cytometry (FACScan) and IMI channel analysis. In addition, CD34-/CD133+ HSC were prepared by a sequential antibody-based positive selection strategy. These cells appeared in the same area as CD34+ cells in the IMI channel of the automated hematology analyzer. These findings confirmed that an automated hematology analyzer can be used to measure both CD34+ and CD34- HSC. These results may explain the difference in HSC/HPC counts sometimes observed between the automated hematology analyzer and flow cytometric methods for CD34+ measurement. The results of this study demonstrated the potential of automated cell counting methods for measuring HSC content in cellular products for both research and clinical applications.

Positional cloning of the rice Rf-1 gene, a restorer of BT-type cytoplasmic male sterility that encodes a mitochondria-targeting PPR protein

The combination of cytoplasmic male sterility (CMS) in one parent and a restorer gene ( Rf) to restore fertility in another are indispensable for the development of hybrid varieties. We have found a rice Rf-1 gene that restores BT-type CMS by applying a positional cloning strategy. Using linkage analysis in combination with 6,104 BC(1)F(3) progeny derived from a cross between two near-isogenic lines (NILs) differing only at the Rf-1 locus, we delimited the Rf-1 gene to a 22.4-kb region in the rice genome. Duplicate open reading frames ( Rf-1A and Rf-1B) with a pentatricopeptide (PPR) motif were found in this region. Since several insertions and/or deletions were found in the regions corresponding to both the Rf-1A and Rf-1B genes in the maintainer's allele, they may have lost their function. Rf-1A protein had a mitochondria-targeting signal, whereas Rf-1B did not. The Rf-1B gene encoded a shorter polypeptide that was determined by a premature stop codon. Based on the function of the Rf-1 gene, its product is expected to target mitochondria and may process the transcript from an atp6/orf79 region in the mitochondrial genome. Since the Rf-1A gene encodes a 791-amino acid protein with a signal targeting mitochondria and has 16 repeats of the PPR motif, we concluded that Rf-1A is the Rf-1 gene. Nine duplications of Rf-1A homologs were found around the Rf-1 locus in the Nipponbare genome. However, while some of them encoded proteins with the PPR motif, they do not restore BT-type CMS based on the lack of co-segregation with the restoration phenotype. These duplicates may have played diversified roles in RNA processing and/or recombination in mitochondria during the co-evolution of these genes and the mitochondrial genome.

Amiloride-sensitive epithelial Na+channel currents in surface cells of rat rectal colon

Surface cells of the mammalian distal colon are shown to molecularly express the amiloride-sensitive epithelial Na+channel composed of three homologous subunits (α-, β-, and γ-ENaC). However, because basic electrophysiological properties of amiloride-sensitive Na+channels expressed in these cells are largely unknown at the cellular level, functional evidence for the involvement of the subunits in the native channels is incomplete. Using electrophysiological techniques, we have now characterized functional properties of native ENaC in surface cells of rectal colon (RC) of rats fed a normal Na+diet. Ussing chamber experiments showed that apical amiloride inhibited a basal short-circuit current in mucosal preparation of RC with an apparent half-inhibition constant ( Ki) value of 0.20 μM. RT-PCR analysis confirmed the presence of transcripts of α-, β-, and γ-rENaC in rectal mucosa. Whole cell patch-clamp experiments in surface cells of intact crypts acutely isolated from rectal mucosa identified an inward cationic current, which was inhibited by amiloride with a Kivalue of 0.12 μM at a membrane potential of –64 mV, the inhibition being weakly voltage dependent. Conductance ratios of the currents were Li+(1.8) > Na+(1) >> K+(≈0), respectively. Amiloride-sensitive current amplitude was almost the same at 15 or 150 mM extracellular Na+, suggesting a high Na+affinity for current activation. These results are consistent with the hypothesis that a heterooligomer composed of α-, β-, and γ-ENaC may be the molecular basis of the native channels, which are responsible for amiloride-sensitive electrogenic Na+absorption in rat rectal colon.

Age of onset possibly associated with the degree of heteroplasmy in two male siblings with diabetes mellitus having an A to G transition at 3243 of mitochondrial DNA

We describe two male siblings with diabetes mellitus caused by mitochondrial 3243 mutation. The level of heteroplasmy in peripheral blood leucocytes was determined by a last-cycle hot PCR method. The younger brother, who had 39% heteroplasmy, developed diabetes at age of 25, and demonstrated a lean body habitus and blunted insulin secretion. The elder brother, who had 22% heteroplasmy, was diagnosed at the age of 42. The younger brother showed a higher increment of serum lactate after exercise. In these siblings the level of heteroplasmy in their peripheral blood leucocytes appeared to be associated with age of onset of diabetes.

Clonality assay of hematopoietic disorders: significance of the buccal epithelium as non-hematopoietic control and of 95% rejection limit as a novel criterion for monoclonality

In clonality assays using X chromosome inactivation patterns (XCIPs), several factors such as constitutive and acquired XCIP skewing, lack of appropriate controls for hematopoietic diseases including multilineage disorders, and ambiguous criteria for monoclonality, have complicated determination of clonality. To address these issues, we studied the significance of the buccal epithelium as a non-hematopoietic control and the usefulness of the 95% rejection limit as a criterion for monoclonality. Sixty-nine females informative for human androgen receptor gene (HUMARA) were divided into "young," "middle-aged" and "elderly" groups. When XCIP correlation between the buccal epithelium, peripheral granulocytes, and peripheral lymphocytes was analyzed, the buccal epithelium showed a good correlation with granulocytes and lymphocytes in "young" and "middle-aged" groups, whereas the correlation was poor for the "elderly" group. For all age groups, there was an excellent correlation between granulocytes and lymphocytes. When we performed clonality assay for seven "young" and "middle-aged" patients with various leukemic phases using buccal epithelium as a non-hematopoietic control, all cases were accurately evaluated with the aid of a novel criterion, the 95% rejection limit. Our findings suggest that the buccal epithelium may constitute an effective control, especially when a non-hematopoietic control is required, and that the 95% rejection limit may serve as a statistically-defined criterion for monoclonality.

Micron, a microsatellite-targeting transposable element in the rice genome

We have isolated a new family of mobile elements, Micron, which occur within microsatellites dispersed throughout the rice (Oryza sativa) genome. The first of these segments, Micron 001, was found in a microsatellite consisting of a (TA)n sequence upstream of the rice phytochrome A (phyA) gene. PCR analysis of related rice species suggests that Micron 001 integrated into this microsatellite locus prior to the divergence of the two wild species O. rufipogon and O. barthii from a common ancestor. Micron elements are short (393-bp), possess subterminal inverted repeats and the single strands have the potential to form stable secondary structures via several internal repeats. Aside from the absence of terminal inverted repeats, these characteristics resemble those of MITEs (Miniature Inverted-Repeat Transposable Elements). We estimate that 100-200 copies of Micron-related sequences are present in the rice nuclear genome, while the chloroplast and mitochondrial genomes lack this sequence. Nineteen homologs of Micron 001 exhibited extremely high nucleotide sequence conservation (greater than 90%), suggesting a recent spread of Micron elements within the genus Oryza. Surprisingly, nucleotide sequence alignments showed that all of the Micron elements are flanked on both sides by microsatellite sequence consisting mainly of (TA)n. Twenty-three elements were mapped to seven separate chromosomes. Therefore Micron elements form a family of dispersed, highly conserved repeats. This is the first report of a transposable element that targets microsatellite loci.

A novel mutation causing complete thyroxine-binding globulin deficiency (TBG-CD-Negev) among the Bedouins in southern Israel

T4-binding globulin (TBG) is the major thyroid hormone transport protein in human serum. Inherited TBG abnormalities do not usually alter the metabolic status and are transmitted in X-linked inheritance. A high prevalence of complete TBG deficiency (TBG-CD) has been reported among the Bedouin population in the Negev (southern Israel). In this study we report a novel single mutation causing complete TBG deficiency due to a deletion of the last base of codon 38 (exon 1), which led to a frame shift resulting in a premature stop at codon 51 and a presumed truncated peptide of 50 residues. This new variant of TBG (TBG-CD-Negev) was found among all of the patients studied. We conclude that a single mutation may account for TBG deficiency among the Bedouins in the Negev. This report is the first to describe a mutation in a population with an unusually high prevalence of TBG-CD.

Construction of an equalized cDNA library from Colletotrichum lagenarium and its application to the isolation of differentially expressed genes

To establish an efficient screening system for differentially expressed genes of a phytopathogenic fungus Colletotrichum lagenarium, we constructed an equalized (normalized) cDNA library from C. lagenarium and used this library for differential screening. For the isolation of genes involved in infection-related developments of conidia, conidia undergoing appressorium differentiation were selected as the source of materials for construction of the cDNA library. The equalization of cDNA was performed twice using a kinetic method, and the products were cloned into a plasmid vector. Colony hybridization with nine probes of different abundance showed a reduction in abundance variation from at least 276-fold in the original library to 10-fold in the equalized cDNA library, which demonstrated that the cDNA was successfully equalized. By differential hybridization of 1900 cDNA clones in the equalized cDNA library and RNA blot analysis of candidate clones, we identified 11 independent cDNA clones, designated CAD1 through CAD11, that were expressed in appressorium-differentiating conidia, but not in vegetative mycelia. The transcripts of CAD1 and CAD2 hardly accumulated in preincubated conidia, whereas those of CAD3 and CAD4 accumulated highly and slightly, respectively. The amount of the four CAD transcripts increased at the early stage of the appressorium formation process. Sequence analysis of CAD1 revealed that CAD1 would encode for 101 amino acid polypeptides, which showed homology to metallothioneins. Deduced amino acid sequence of CAD2 would encode 278 amino acid polypeptides, and showed high homology to genes in aflatoxin, and sterigmatocystin gene clusters of Aspergillus parasiticus and A. nidulans, respectively.

Intermolecular Activation of n-Alkanes by a Trinuclear Ruthenium Pentahydride Complex-Formation of closo-Ruthenacyclopentadiene Complexes

The successive activation of alkane C-H bonds on a trinuclear ruthenium cluster enables cleavage of six C-H bonds and the formation of a closo-ruthenacyclopentadiene complex (the structure of the complex obtained with hexane is shown).

Probiotic bacteria stimulate gut epithelial cell proliferation in rat

Probiotics are used for various intestinal diseases. However, their effects on gut epithelial cell proliferation have not been investigated. We administered 10(7) colony-forming units of Lactobacillus casei or Clostridium butyricum, or no probiotics (control) by gastric intubation once a day for seven days to rats fed an elemental diet. We estimated the crypt cell production rate of the jejunum, ileum, cecum, and distal colon. We also quantified cecal bacteria. Both probiotics increased the crypt cell production rate of the jejunum and ileum by 25-40%, of the cecum by 70%, and of the distal colon by more than 200% compared with control. Only minor variance in the cecal bacterial composition existed among the three groups. Probiotics enhanced gut epithelial cell proliferation in rats fed an elemental diet.

Origin and evolution of twin microsatellites in the genus Oryza

An ancestral sequence of twin microsatellites of rice was found in a wild species. Twin microsatellite loci, RM20A and RM20B, were located on separate regions of chromosomes 11 and 12, which had been duplicated during rice evolution. These twin microsatellites showed different allele diversities in A genome species of the genus Oryza. This difference was caused by repetition of a simple sequence consisting of (TAA)n. Oryza longistaminata contains a short poly(A) sequence in this region instead of the poly(TAA) found in other species. A sequence comparison of RM20-related amplicons suggested that the poly(A)-containing sequence is the ancestral sequence of the RM20A and RM20B microsatellites. A simple base substitution in the poly(A) sequence may have produced the longer microsatellite motif (TAA). This mutation may have occurred on one of the chromosomes of a hypothetical ancestor of the A genome species before duplication of the chromosome segments.

Age-associated decrease in response of rat aquaporin-2 gene expression to dehydration

It is well known that urine-concentrating ability decreases with aging and that this decreasing ability results from a reduced sensitivity of the renal collecting duct to arginine vasopressin (AVP). AVP regulates the water channel (aquaporin-2:AQP2) through V2 receptors and increases the water permeability of the collecting duct. To elucidate the mechanism of change with aging in urine-concentrating ability, we investigated the change of V2 receptor and AQP2 mRNA expression in young (8-week-old) and older (7-month-old) rats after dehydration for 2 days. After dehydration, plasma AVP levels in older rats were higher than young rats, and urinary osmolality in older rats was lower than young rats. By Northern blot analysis, there was no significant difference between young and older rats in both V2 receptor and AQP2 mRNA expression before dehydration. After dehydration, V2 receptor mRNA expression in young and older rats decreased in the same degree, suggesting the downregulation of V2 receptors may occur in the mRNA level. Northern blot analysis and in situ hybridization histochemistry showed that AQP2 mRNA expression increased and the increased expression in older rats was less than in young rats. The present study suggests the reduced response of AQP2 mRNA expression to dehydration, observed in 7-month-old rats, might be partially responsible for the decreasing urine-concentrating ability with aging.