Current Status of Taeniasis in Thailand

Taeniasis is prevalent in all regions of Thailand, except the South. Infections were more frequently found in males than females of any age from 7-83 years. Taenia saginata is the most common species throughout the country. Taenia asiatica was reported only in the province of Kanchanaburi in the Central region. Co-infections, with Taenia solium and T. asiatica or T. solium and T. saginata, were found. Hybridization between T. asiatica and T. saginata is evidence that co-infection is never found between these 2 species. Finding more than 1 worm in a single patient was not entirely rare. Genetic variation was found without correlation to its geographic distribution in T. saginata, whereas no variation was found in T. asiatica.     

ABO Genetic Variation in Neanderthals and Denisovans

Variation at the ABO locus was one of the earliest sources of data in the study of human population identity and history, and to this day remains widely genotyped due to its importance in blood and tissue transfusions. Here, we look at ABO blood type variants in our archaic relatives: Neanderthals and Denisovans. Our goal is to understand the genetic landscape of the ABO gene in archaic humans, and how it relates to modern human ABO variation. We found two Neanderthal variants of the O allele in the Siberian Neanderthals (O1 and O2), one of these variants is shared with an European Neanderthal, who is a heterozygote for this O1 variant and a rare cis-AB variant. The Denisovan individual is heterozygous for two variants of the O1 allele, functionally similar to variants found widely in modern humans. Perhaps more surprisingly, the O2 allele variant found in Siberian Neanderthals can be found at low frequencies in modern Europeans and Southeast Asians, and the O1 allele variant found in Siberian and European Neanderthal is also found at very low frequency in modern East Asians. Our genetic distance analyses suggest both alleles survive in modern humans due to inbreeding with Neanderthals. We find that the sequence backgrounds of the surviving Neanderthal-like O alleles in modern humans retain a higher sequence divergence than other surviving Neanderthal genome fragments, supporting a view of balancing selection operating in the Neanderthal ABO alleles by retaining highly diverse haplotypes compared with portions of the genome evolving neutrally.     

The Bifunctional Cell Wall Hydrolase CwlT Is Needed for Conjugation of the Integrative and Conjugative Element ICEBs1 in Bacillus subtilis and B. anthracis

The mobile genetic element ICEBs1 is an integrative and conjugative element (ICE) found in Bacillus subtilis. One of the ICEBs1 genes, cwlT, encodes a cell wall hydrolase with two catalytic domains, a muramidase and a peptidase. We found that cwlT is required for ICEBs1 conjugation. We examined the role of each of the two catalytic domains and found that the muramidase is essential, whereas the peptidase is partially dispensable for transfer of ICEBs1. We also found that the putative signal peptide in CwlT is required for CwlT to function in conjugation, consistent with the notion that CwlT is normally secreted from the cytoplasm. We found that alteration of the putative lipid attachment site on CwlT had no effect on its role in conjugation, indicating that if CwlT is a lipoprotein, the lipid attachment is not required for conjugation. Finally, we found conditions supporting efficient transfer of ICEBs1 into and out of Bacillus anthracis and that cwlT was needed for ICEBs1 to function in B. anthracis. The mature cell wall of B. anthracis is resistant to digestion by CwlT, indicating that CwlT might act during cell wall synthesis, before modifications of the peptidoglycan are complete.     

Nuclear interactions in a heterokaryon: insight from the model Neurospora tetrasperma

A heterokaryon is a tissue type composed of cells containing genetically different nuclei. Although heterokaryosis is commonly found in nature, an understanding of the evolutionary implications of this phenomenon is largely lacking. Here, we use the filamentous ascomycete Neurospora tetrasperma to study the interplay between nuclei in heterokaryons across vegetative and sexual developmental stages. This fungus harbours nuclei of two opposite mating types (mat A and mat a) in the same cell and is thereby self-fertile. We used pyrosequencing of mat-linked SNPs of three heterokaryons to demonstrate that the nuclear ratio is consistently biased for mat A-nuclei during mycelial growth (mean mat A/mat a ratio 87%), but evens out during sexual development (ratio ranging from 40 to 57%). Furthermore, we investigated the association between nuclear ratio and expression of alleles of mat-linked genes and found that expression is coregulated to obtain a tissue-specific bias in expression ratio: during mycelial extension, we found a strong bias in expression for mat A-linked genes, that was independent of nuclear ratio, whereas at the sexual stage we found an expression bias for genes of the mat a nuclei. Taken together, our data indicate that nuclei cooperate to optimize the fitness of the heterokaryon, via both altering their nuclear ratios and coregulation genes expressed in the different nuclei.     

Chromosomal Location of Pleiotropic Negative Sporulation Mutations in BACILLUS SUBTILIS

Genetic analysis by PBS-1 transduction and transformation of a large group of pleiotropic negative sporulation mutants has shown that mutations of this phenotype may be located in five genetically distinct regions. The first group of mutant sites, spoA mutations, is located in the terminal region of the chromosome and linked to the lys-1 marker by PBS-1 transduction. The second group, spoB mutations, is located between phe-1 and the attachment site for the lysogenic bacteriophage ϕ 105. Fine structure analysis of the mutant sites within the spoB locus has been accomplished. A third location for mutants of this phenotype, spoE mutants, was found between the metC3 and ura-1 markers. Two mutants were found at this site and both were capable of sporulation, in contrast to the rest of the pleiotropic sporulation mutants. A fourth chromosomal site, spoH mutations, was found near the ribosomal and RNA polymerase loci. A large group of mutant sites, spoF mutations, was found to be linked to each other by recombination index analysis in transformation but unlinked to any of the known auxotrophic mutations comprising the chromosomal map. All mutants analyzed showing a pleiotropic negative phenotype were found to map within one of these five regions. Interspecific transformation with Bacillus amyloliquefaciens as donor has shown that all of the pleiotropic negative sporulation mutations are conserved relative to a selected group of auxotrophic markers. The degree of conservation in decreasing order is: spoH > spoF = spoB > spoA.     

Hybridization in Annual Plants: Patterns and DynamicsDuring a Four-Year Study in Mixed Rhinanthus Populations

Hybridization in annual plants is rare, but their short life cycle provides an excellent opportunity to study the dynamics of hybridization. Hybridization occurs between the annual hemiparasites Rhinanthus minor and Rhinanthus angustifolius (Orobanchaceae). Using flower morphology, Kwak (1980) found a prevalence of hybrids close to R. angustifolius in a single population. We aim to find whether this pattern is also found using genetic markers, whether it is generally occurring in mixed populations, and whether these populations are stable over time. We used species-specific genetic markers to determine the number of individuals in a range of hybrid classes in three mixed populations of different ages during four consecutive years. In the young population, F₁ hybrids were found in the first year and mostly hybrids between R. minor and these F₁s in the second year, but in the years after that, hybrids close to R. angustifolius became more abundant. We also found this in the two older populations, where hybrids close to R. angustifolius always occurred in higher frequencies than hybrids close to R. minor. Over time, R. angustifolius strongly increased in frequency in two populations. Patterns of marker presence and absence suggested that advanced-generation hybrids are mainly formed by backcrossing with one of the parents, predominantly R. angustifolius whenever its frequency in the population is higher than 15%. The dynamics of mixed populations depend on the ecological conditions that regulate the presence of the two parental species, and introgression into R. angustifolius seems prevalent.     

Amphibian Pathogens in Southeast Asian Frog Trade

Amphibian trade is known to facilitate the geographic spread of pathogens. Here we assess the health of amphibians traded in Southeast Asia for food or as pets, focusing on Batrachochytrium dendrobatidis (Bd), ranavirus and general clinical condition. Samples were collected from 2,389 individual animals at 51 sites in Lao PDR, Cambodia, Vietnam and Singapore for Bd screening, and 74 animals in Cambodia and Vietnam for ranavirus screening. Bd was found in one frog (n = 347) in Cambodia and 13 in Singapore (n = 419). No Bd was found in Lao PDR (n = 1,126) or Vietnam (n = 497), and no ranavirus was found in Cambodia (n = 70) or Vietnam (n = 4). Mild to severe dermatological lesions were observed in all East Asian bullfrogs Hoplobatrachus rugolosus (n = 497) sampled in farms in Vietnam. Histologic lesions consistent with sepsis were found within the lesions of three frogs and bacterial sepsis in two (n = 4); one had Gram-negative bacilli and one had acid-fast organisms consistent with mycobacterium sp. These results confirm that Bd is currently rare in amphibian trade in Southeast Asia. The presence of Mycobacterium-associated disease in farmed H. rugolosus is a cause for concern, as it may have public health implications and indicates the need for improved biosecurity in amphibian farming and trade.     

Mutations in genes encoding complement inhibitors CD46 and CFH affect the age at nephritis onset in patients with systemic lupus erythematosus

Introduction

Inherited deficiencies of several complement components strongly predispose to systemic lupus erythematosus (SLE) while deficiencies of complement inhibitors are found in kidney diseases such as atypical hemolytic uremic syndrome (aHUS).

Methods

The exons of complement inhibitor genes CD46 and CFH (factor H) were fully sequenced using the Sanger method in SLE patients with nephritis originating from two cohorts from southern and mid Sweden (n = 196). All identified mutations and polymorphisms were then analyzed in SLE patients without nephritis (n = 326) and in healthy controls (n = 523).

Results

We found nonsynonymous, heterozygous mutations in CFH in 6.1% patients with nephritis, in comparison with 4.0% and 5.4% in patients without nephritis and controls, respectively. No associations of SLE or nephritis with common variants in CFH (V62I/Y402H/E936D) were found. Furthermore, we found two nonsynonymous heterozygous mutations in CD46 in SLE patients but not in controls. The A353V polymorphism, known to affect function of CD46, was found in 6.6% of nephritis patients versus 4.9% and 6.1% of the non-nephritis SLE patients and controls. The presence of mutations in CD46 and CFH did not predispose to SLE or nephritis but was associated with earlier onset of nephritis. Furthermore, we found weak indications that there is one protective and one risk haplotype predisposing to nephritis composed of several polymorphisms in noncoding regions of CD46, which were previously implicated in aHUS.

Conclusions

SLE nephritis is not associated with frequent mutations in CFH and CD46 as found in aHUS but these may be modifying factors causing earlier onset of nephritis.     

New Mechanisms of Flucytosine Resistance in C. glabrata Unveiled by a Chemogenomics Analysis in S. cerevisiae

5-Flucytosine is currently used as an antifungal drug in combination therapy, but fungal pathogens are rapidly able to develop resistance against this drug, compromising its therapeutic action. The understanding of the underlying resistance mechanisms is crucial to deal with this problem. In this work, the S. cerevisiae deletion mutant collection was screened for increased resistance to flucytosine. Through this chemogenomics analysis, 183 genes were found to confer resistance to this antifungal agent. Consistent with its known effect in DNA, RNA and protein synthesis, the most significant Gene Ontology terms over-represented in the list of 5-flucytosine resistance determinants are related to DNA repair, RNA and protein metabolism. Additional functional classes include carbohydrate and nitrogen—particularly arginine—metabolism, lipid metabolism and cell wall remodeling. Based on the results obtained for S. cerevisiae as a model system, further studies were conducted in the pathogenic yeast Candida glabrata. Arginine supplementation was found to relieve the inhibitory effect exerted by 5-flucytosine in C. glabrata. Lyticase susceptibility was found to increase within the first 30min of 5-flucytosine exposure, suggesting this antifungal drug to act as a cell wall damaging agent. Upon exponential growth resumption in the presence of 5-flucytosine, the cell wall exhibited higher resistance to lyticase, suggesting that cell wall remodeling occurs in response to 5-flucytosine. Additionally, the aquaglyceroporin encoding genes CgFPS1 and CgFPS2, from C. glabrata, were identified as determinants of 5-flucytosine resistance. CgFPS1 and CgFPS2 were found to mediate 5-flucytosine resistance, by decreasing 5-flucytosine accumulation in C. glabrata cells.     

A novel Fomitiporia species associated with esca on grapevine in South Africa

Esca disease of grapevine is a complex trunk disease consisting of several symptoms, one of which, white rot, has been found to be caused by various basidiomycetes within the order Hymenochaetales. During recent surveys of esca-related pathogens in South African vineyards, several unidentified basidiomycetes were isolated from white rot occurring in diseased vines. A new Fomitiporia species, F. capensis, is described based on fruit body morphology and combined internal transcribed spacer (ITS) and large-subunit (LSU) phylogeny, where it forms a clearly delineated and well-supported clade. Morphologically, F. capensis is similar to F. punctata in that both species essentially lack setae. Fomitiporia capensis, F. punctata and F. aethiopica produce similarly sized basidiospores but differ in terms of host range, pore size and, possibly, fruit body shape. Phylogenetically, F. capensis appears to be related to F. tenuis, though morphologically, the species differ significantly in that F. tenuis has smaller pores and smaller basidiospores. Fomitiporia capensis was found to occur widely as vegetative mycelium throughout the Western Cape Province, though fruit bodies were scarce in comparison. A vineyard with fruit bodies was also found in Limpopo in the north east of the country. Fruit bodies were found growing on the underside of the cordon of living vines displaying external symptoms typically associated with esca, or general decline and dieback symptoms together with internal white rot.     

A Tn7-Like Transposon Is Present in the glmUS Region of the Obligately Chemoautolithotrophic Bacterium Thiobacillus ferrooxidans

The region downstream of the Thiobacillus ferrooxidans ATCC 33020 atp operon was examined, and the genes encoding N-acetylglucosamine-1-uridyltransferase (glmU) and glucosamine synthetase (glmS) were found. This atpEFHAGDC-glmUS gene order is identical to that of Escherichia coli. The T. ferrooxidans glmS gene was shown to complement E. coli glmS mutants for growth on minimal medium lacking glucosamine. A Tn7-like transposon, Tn5468, was found inserted into the region immediately downstream of the glmS gene in a manner similar to the site-specific insertion of transposon Tn7 within the termination region of the E. coli glmS gene. Tn5468 was sequenced, and Tn7-like terminal repeat sequences as well as several open reading frames which are related to the Tn7 transposition genes tnsA, tnsB, tnsC, and tnsD were found. Tn5468 is the closest relative of Tn7 to have been characterized to date. Southern blot hybridization indicated that a similar or identical transposon was present in three T. ferrooxidans strains isolated from different parts of the world but not in two Thiobacillus thiooxidans strains or a Leptospirillum ferrooxidans strain. Since T. ferrooxidans is an obligately acidophilic autotroph and E. coli is a heterotroph, ancestors of the Tn7-like transposons must have been active in a variety of physiologically different bacteria so that their descendants are now found in bacteria that occupy very different ecological niches.     

The diversity,recombination and horizontal transmission of Wolbachia in spiders in China

Wolbachia are maternally inherited endosymbiotic bacteria. These intracellular bacteria are common in arthropods and could manipulate host reproduction in diverse ways, such as feminization, parthenogenesis, male killing and cytoplasmic incompatibility. In spiders, infection by Wolbachia has been found in a total of 99 species belonging to 62 genera and 17 families. Furthermore, recent studies analyzed the phylogeny of Wolbachia in Hylyphantes graminicola, 2 cave spiders and Agelenopsis species using multilocus sequence typing (MLST) approach. However, the diversity of Wolbachia strains determined by MLST in spiders from China is still largely unknown.In this study, we collected 1153 spider individuals from Mangshan in China and screened for Wolbachia in 975 individuals representing 68 spider species belonging to 45 genera of 16 families. We analyzed the phylogenetic relationship between Wolbachia and their host spiders by MLST approach. We found novel infections of Wolbachia in 1 family, 9 genera and 20 species of spiders. We found 13 new Wolbachia strains and suggest that group A is more common than group B in Wolbachia that infect spiders. Our results revealed three recombination events of the concatenated multilocus sequences in Wolbachia that infect spiders. Furthermore, our results demonstrated the phylogenetic incongruence between Wolbachia and spiders, suggesting the horizontal transmission of Wolbachia in spiders.We suggest that recombination and horizontal transmission may play an important role in the diversity and evolution of Wolbachia in spiders.     

Role of Trehalose Synthesis in Ralstonia syzygii subsp. indonesiensis PW1001 in Inducing Hypersensitive Response on Eggplant (Solanum melongena cv. Senryo-nigou)

Ralstonia syzygii subsp. indonesiensis (Rsi, former name: Ralstonia solanacearum phylotype IV) PW1001, a causal agent of potato wilt disease, induces hypersensitive response (HR) on its non-host eggplant (Solanum melongena cv. Senryo-nigou). The disaccharide trehalose is involved in abiotic and biotic stress tolerance in many organisms. We found that trehalose is required for eliciting HR on eggplant by plant pathogen Rsi PW1001. In R. solanacearum, it is known that the OtsA/ OtsB pathway is the dominant trehalose synthesis pathway, and otsA and otsB encode trehalose-6-phosphate (T6P) synthase and T6P phosphatase, respectively. We generated otsA and otsB mutant strains and found that these mutant strains reduced the bacterial trehalose concentration and HR induction on eggplant leaves compared to wild-type. Trehalose functions intracellularly in Rsi PW1001 because addition of exogenous trehalose did not affect the HR level and ion leakage. Requirement of trehalose in HR induction is not common in R. solanacearum species complex because mutation of otsA in Ralstonia pseudosolanacearum (former name: Ralstonia solanacearum phylotype I) RS1002 did not affect HR on the leaves of its non-host tobacco and wild eggplant Solanum torvum. Further, we also found that each otsA and otsB mutant had reduced ability to grow in a medium containing NaCl and sucrose, indicating that trehalose also has an important role in osmotic stress tolerance.     

New Flagellin-Specifying Genes in Some Escherichia coli Strains

Data for further development of the flagellar antigen genetics of the species Escherichia coli are reported. Two new flagellin genes named fllA and flmA were found in E. coli 781-55, E2987-73, and E223-69, the test strains for E. coli flagellar antigens H44, H55, and H54, respectively (collection of the International Escherichia and Klebsiella Centre of the World Health Organization, Copenhagen, Denmark). Two alleles of fllA were identified that encode flagellar antigens H44 (fllA₄₄) and H55 (fllA₅₅), and the only flmA allele found (flmA₅₄) encodes antigen H54. The sites of their integration in the E. coli K-12 chromosome after P1-mediated transduction were approximately determined and found to be separate from each other and from the known regions of flagellar genes of E. coli and salmonellae. The region of flm₅₄ was found to repress the expression of some alleles of the flagellin gene fliC. In addition, cryptic genes encoding antigens H4 and H38 were found in phenotypically monophasic test strains 781-55 and E2987-73, respectively.     

Cytogenetics of the South American DROSOPHILA MULLERI Complex: The MARTENSIS Cluster. More Interspecific Sharing of Inversions

Three Drosophila mulleri complex species have been found to be endemic to the cactus regions of northern South America. The three species are morphologically distinct, and no hybridization between species has been found in either the laboratory or nature. An analysis of their salivary gland chromosomes revealed that they evolved from a single cytological population, subspecies F of the ancestor of the D. mulleri complex, and comprise a cluster of sister species that are homozygous for inversions not found elsewhere. Within the martensis cluster are also found several inversions that are unique for these species, but have segregated out among the three species. Thus 2f² is found in martensis and starmeri, but not in uniseta, while 2t⁶, 3v and 3w are found in starmeri and uniseta, but not in martensis. This is analogous to the situation found within the remainder of the mulleri complex species, all the members of which share homozygosity for six other inversions. An interpretation of the cytological evolution of the martensis cluster is proposed.     

Benzoxazinoid biosynthesis in dicot plants

Benzoxazinoids are common defence compounds of the grasses and are sporadically found in single species of two unrelated orders of the dicots. In the three dicotyledonous species Aphelandra squarrosa, Consolida orientalis and Lamium galeobdolon the main benzoxazinoid aglucon is 2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one (DIBOA). While benzoxazinoids in Aphelandra squarrosa are restricted to the root, in Consolida orientalis and Lamium galeobdolon DIBOA is found in all above ground organs of the adult plant in concentrations as high as in the seedling of maize. The initial biosynthetic steps in dicots and monocots seem to be identical. Indole is most probably the first specific intermediate that is oxygenated to indolin-2-one by a cytochrome P450 enzyme. C. orientalis has an active indole-3-glycerolphosphate lyase for indole formation that evolved independently from its orthologous function in maize. The properties and evolution of plant indole-3-glycerolphosphate lyases are discussed.     

Characterization of a Mutation in Yeast Causing Nonrandom Chromosome Loss during Mitosis

Diploid strains of the yeast Saccharomyces cerevisiae homozygous for a recessive chromosome loss mutation (chl) exhibit a high degree of mitotic instability. Cells become monosomic for chromosome III at a frequency of approximately one percent of all cell divisions. Chromosome loss at this high frequency is also found for chromosome I, and at lesser frequencies for chromosomes VIII and XVI. In contrast, little or no chromosome loss is found for six other linkage groups tested (II, V, VI, VII, XI and XVII). The chl mutation also induces a ten-fold increase in both intergenic and intragenic mitotic recombination on all ten linkage groups tested. The chl mutation does not cause an increase in spontaneous mutations, nor are mutant strains sensitive to UV or γ irradiation. The effects of chl during meiosis are observed primarily in reduced spore viability. A decrease in chromosome III linkage relationships is also found.     

Centipede (Chilopoda) richness and diversity in the Bug River valley (Eastern Poland)

The main aim of the survey was to describe the diversity and richness of Chilopoda in the selected area of the Bug River valley. The study sites were located in two regions differing in the shape of the valley, the presence of thermophilous habitats and the size of riparian forests. Pitfall traps were used as a sampling method. As a result, 444 specimens belonging to 12 centipede species of two orders – Geophilomorpha (four species) and Lithobiomorpha (eight species) were caught. Lithobius (Monotarsobius) curtipes C.L.Koch, 1847, Pachymerium ferrugineum (C.L.Koch, 1835), Lamyctes (Lamyctes) emarginatus (Newport, 1844) and Lithobius (Monotarsobius) dudichi Loksa, 1947 were the most common and the most numerous species. Of particular note is Lithobius dudichi found in Poland for the first time and previously known based on a single specimen. Two to 10 Chilopoda species were found in each habitat under investigation. The greatest species richness was found in thermophilous thickets (10 species), sandy grasslands (eight), xerothermic grasslands (eight) and mesic meadows (six). The fewest number of species (two) was found in rushes at oxbows and in wet meadows. We found differences in the species composition and the number of Chilopoda between the lower (102 specimens, six species) and the middle (324 specimens, 11 species) section of the river valley. Our results confirm the need to protect xerothermic habitats, unique almost throughout entire Central Europe, which due to their distribution and their small area covered are fairly easily subject to the process of destruction.