225 research outputs found

    Molecular insights into the biogeography and species status of New Zealand's endemic Latrodectus spider species; L. katipo and L. atritus (Araneae, Theridiidae)

    Get PDF
    New Zealand's endemic sand dune Latrodectus widow spider species, L. katipo and L. atritus, possess behavioral and physiological attributes likely to promote dispersal over large distances. Morphological, physiological and behavioural similarities between L. katipo and L. hasselti, an Australian endemic, suggest gene flow may occur across the Tasman Sea. In this study we examine intraspecific and interspecific genetic relationships within the ND1 gene region between L. katipo, L. atritus, L. hasselti and L. hesperus to assess whether the genetic evidence supports current taxonomic species designations. We found low interspecific pairwise distances among L. katipo and L. atritus populations, suggesting either introgression, incomplete lineage sorting, or that the current taxonomic distinction between the two species may be invalid. Parsimony and maximum likelihood analyses were inconclusive as to the relationships between the New Zealand Latrodectus species and the Australian L. hasselti. Low pairwise distances between L. hasselti and the New Zealand widow fauna indicated that L. katipo and L. atritus were not present in New Zealand before the fragmentation of Gondwana

    Ovarian reserve and anti-Mullerian hormone (AMH) in mothers of dizygotic twins

    Get PDF
    This study aimed to explore if natural dizygotic (DZ) twinning is associated with earlier menopause and lower anti-Mullerian hormone (AMH) values. We investigated if advanced biological reproductive aging, which can be responsible for the multiple follicle growth in familial twinning, is similar to mechanisms that occur in normal ovarian aging, reflected by earlier menopause in mothers of DZ twins and lower levels of AMH. A total of 16 mothers of DZ twins enrolled with the Netherlands Twin Register (average age at first assessment: 35.9 +/- 3.0 years) and 14 control mothers (35.1 +/- 3 years) took part in a prospective study. Fifteen years after entry into the study, which included follicle-stimulating hormone (FSH) assessment, AMH was measured in stored serum samples and menopause status was evaluated. Average AMH levels were not significantly different between DZ twin mothers and controls (2.1 +/- 2.4 mu g/L vs. 1.9 +/- 1.9 mu g/L). Among the 16 mothers of twins, 7 had an elevated (FSH) value over 10 U/L at first assessment. Their AMH levels were lower than the nine twin mothers with normal FSH values: 0.6 +/- 0.4 versus 3.4 +/- 2.6 mu g/L (p = .01). Of the mothers of twins, eight mothers had entered menopause at the second assessment compared with only one control mother (p = .07). Thus, slightly more DZ mothers were in menopause than the control mothers, although this difference was not significant. The subgroup of DZ twin mothers who had an increased FSH concentration 15 years ago had a limited ovarian reserve as reflected by lower AMH levels. These data indicate that advanced ovarian aging can be a feature in familial DZ twinning, particularly with elevated early follicular phase FSH

    The Mycoplasma pneumoniae MPN229 gene encodes a protein that selectively binds single-stranded DNA and stimulates Recombinase A-mediated DNA strand exchange

    Get PDF
    Background. Mycoplasma pneumoniae has previously been characterized as a micro-organism that is genetically highly stable. In spite of this genetic stability, homologous DNA recombination has been hypothesized to lie at the basis of antigenic variation of the major surface protein, P1, of M. pneumoniae. In order to identify the proteins that may be involved in homologous DNA recombination in M. pneumoniae, we set out to characterize the MPN229 open reading frame (ORF), which bears sequence similarity to the gene encoding the single-stranded DNA-binding (SSB) protein of other micro-organisms. Results. The MPN229 ORF has the capacity to encode a 166-amino acid protein with a calculated molecular mass of 18.4 kDa. The amino acid sequence of this protein (Mpn SSB) is most closely related to that of the protein predicted to be encoded by the MG091 gene from Mycoplasma genitalium (61% identity). The MPN229 ORF was cloned, and different versions of Mpn SSB were expressed in E. coli and purified to > 95% homogeneity. The purified protein was found to exist primarily as a homo-tetramer in solution, and to strongly and selectively bind single-stranded DNA (ssDNA) in a divalent cation- and DNA substrate sequence-independent manner. Mpn SSB was found to bind with a higher affinity to ssDNA substrates larger than 20 nucleotides than to smaller substrates. In addition, the protein strongly stimulated E. coli Recombinase A (RecA)-promoted DNA strand exchange, which indicated that Mpn SSB may play an important role in DNA recombination processes in M. pneumoniae. Conclusion. The M. pneumoniae MPN229 gene encodes a protein, Mpn SSB, which selectively and efficiently binds ssDNA, and stimulates E. coli RecA-promoted homologous DNA recombination. Consequently, the Mpn SSB protein may play a crucial role in DNA recombinatorial pathways in M. pneumoniae. The results from this study will pave the way for unraveling these pathways and assess their role in antigenic variation of M. pneumoniae

    Liquefaction Characteristics of Sand as Studied by Cyclic Torsional Testing Using Hollow Cylinder Apparatus

    Get PDF
    The DNA recombination and repair machineries of Mycoplasma genitalium and Mycoplasma pneumoniae differ considerably from those of gram-positive and gram-negative bacteria. Most notably, M. pneumoniae is unable to express a functional RecU Holliday junction (HJ) resolvase. In addition, the RuvB homologues from both M. pneumoniae and M. genitalium only exhibit DNA helicase activity but not HJ branch migration activity in vitro. To identify a putative role of the RuvA homologues of these mycoplasmas in DNA recombination, both proteins (RuvA(Mpn) and RuvA(Mge), respectively) were studied for their ability to bind DNA and to interact with RuvB and RecU. In spite of a high level of sequence conservation between RuvA(Mpn) and RuvA(Mge) (68.8% identity), substantial differences were found between these proteins in their activities. First, RuvA(Mge) was found to preferentially bind to HJs, whereas RuvA(Mpn) displayed similar affinities for both HJs and single-stranded DNA. Second, while RuvA(Mpn) is able to form two distinct complexes with HJs, RuvA(Mge) only produced a single HJ complex. Third, RuvA(Mge) stimulated the DNA helicase and ATPase activities of RuvB(Mge), whereas RuvA(Mpn) did not augment RuvB activity. Finally, while both RuvA(Mge) and RecU(Mge) efficiently bind to HJs, they did not compete with each other for HJ binding, but formed stable complexes with HJs over a wide protein concentration range. This interaction, however, resulted in inhibition of the HJ resolution activity of RecU(Mge)

    Review of the Australian and New Zealand orb-weaving spider genus Novakiella (Araneae, Araneidae)

    Get PDF
    The orb-weaving spider genus Novakiella Court & Forster, 1993 (family Araneidae Clerck, 1757) is reviewed to include two species, N. trituberculosa (Roewer, 1942) (type species, Australia and New Zealand) and N. boletus sp. nov. (Australia). Novakiella belongs to the informal, largely Australian ‘backobourkiine’ clade and shares with the other genera of the clade a single macroseta on the male pedipalp patella and a median apophysis of the male pedipalp that forms an arch over the radix. The proposed genus synapomorphies are the presence of a large basal conductor lobe expanding apically over the radix and the shape of the median apophysis, which extends into a basally directed, pointy projection. Males have an apico-prolateral spur on the tibia of the second leg that carries a distinct spine. Females have an epigyne with triangular base plate bearing transverse ridges and an elongate triangular scape, which is almost always broken off. The humeral humps of the abdomen are distinct. Novakiella trituberculosa build characteristic dome-shaped webs; however, the foraging behaviour and web-shape of N. boletus sp. nov., currently only known from museum specimens, are not known

    Infection with and carriage of Mycoplasma pneumoniae in children

    Get PDF
    "Atypical" pneumonia was described as a distinct and mild form of community-acquired pneumonia (CAP) already before Mycoplasma pneumoniae had been discovered and recognized as its cause. M. pneumoniae is detected in CAP patients most frequently among school-aged children from 5 to 15 years of age, with a decline after adolescence and tapering off in adulthood. Detection rates by polymerase chain reaction (PCR) or serology in children with CAP admitted to the hospital amount 4-39%. Although the infection is generally mild and self-limiting, patients of every age can develo

    Spider and harvestmen biodiversity in New Zealand horticultural ecosystems

    Get PDF
    Spiders contribute to pest suppression in agroecosystems by direct and non-direct consumption. They provide an ecosystem service which provides economic gains to horticultural growing systems, such as apples, wine grapes, and kiwifruit. Very few studies on spider biodiversity in cropping systems have been completed in New Zealand, and no studies have been published for New Zealand orchard systems. In this study, spiders and harvestmen were sampled from vineyards, apple orchards, and kiwifruit orchards in three New Zealand locations, Waipara, Motueka, and Kerikeri. Spiders were sampled using pitfall traps, sweep netting, active day sampling, and active night sampling. A total of 1359 spiders and 87 Opiliones were caught in this study, from 17 families and 31 species. Sixteen of the 31 (51.6%) species found were introduced, 9 (29%) endemic to New Zealand, two species (6.4%) native to New Zealand, and four (12.9%) unknown. There were five dominant spider families caught (Araneidae, Lycosidae, Theridiidae, Linyphiidae, and Desidae), and of the adults, there were five dominant species: Anoteropsis hilaris, Tenuiphantes tenuis, Cryptachaea veruculata, Cryptachaea blattea, and Steatoda capensis. This study provides the first important step in describing the spider families and species found in three economically important New Zealand horticultural systems

    Molecular characterization of methicillin-resistant Staphylococcus aureus bloodstream isolates from

    Get PDF
    Objectives: The objectives of this study were (i) to investigate the genetic background of methicillinresistant Staphylococcus aureus (MRSA) bloodstream isolates from Croatia and (ii) to monitor the prevalence of Panton-Valentine leucocidin (PVL) and toxic shock syndrome toxin-1 (TSST-1) among these isolates. Methods: Eighty-two hospital-acquired MRSA bloodstream isolates, collected in 2001 and 2002 in Croatia, were characterized by PFGE, staphylococcal cassette chromosome mec (SCCmec) typing and multilocus sequence typing (MLST). The presence of genes encoding PVL and TSST-1 was investigated by realtime PCR. Results: All strains were multiresistant and were distributed among 16 different similarity groups as determined by PFGE. Two of the groups, groups H and K, harboured the majority of the MRSA strains with 52 and 12%, respectively. The predominant SCCmec type found among the isolates was type I (89%). Eleven per cent of the strains harboured a modified SCCmec type III, which contained, in contrast to the regular type III, an additional dcs region. One strain harboured a novel SCCmec type, containing the ccrC gene in combination with the mecI gene, the dcs region, the locus between pI258 and Tn554 (locus E) and the locus between Tn554 and orfX (locus F). MLST showed the presence of ST111-MRSA-I and ST247-MRSA-I among Croatian MRSA isolates. All isolates were negative for both PVL and TSST-1. Conclusions: These results indicate the emergence of ST111-MRSA-I and ST247-MRSA-I in Croatia among MRSA bloodstream isolates. The virulence factors PVL and TSST-1 were not present among these isolates

    Conservation status of New Zealand Araneae (spiders), 2020

    Get PDF
    The conservation status of 1156 New Zealand Araneae (spider) taxa was assessed using the New Zealand Threat Classification System (NZTCS). A list of these taxa is presented, along with a statistical summary and brief notes on the most important changes. This list replaces all previous NZTCS lists for Araneae. Of the Araneae taxa assessed in this review, 4 are Threatened, 182 are At Risk and 428 are Not Threatened; 49 are Introduced and Naturalised and 493 Data Deficient because insufficient information is available to assess their conservation status. In addition, 24 ‘taxa’ are listed as taxonomically unresolved. These include 7 ‘taxa’ that are believed to be multiple species. Of these 7 ‘taxa’, 3 are listed as formally described and named species

    Prevalence of Polycystic Ovary Syndrome in Women from Opposite-Sex Twin Pairs

    Get PDF
    Introduction: Intrauterine androgens of a male fetus may influence the female fetus in opposite-sex twin pairs. Because female intrauterine overexposure to androgens could lead to polycystic ovary syndrome (PCOS), the prevalence of PCOS should be higher in women from opposite-sex twin pairs. Therefore, the aim of the current study was to evaluate the prevalence of PCOS in women from opposite-sex twin pairs compared to women from same-sex twin pairs, sisters, and female spouses of twins. Subjects and Methods: Data from 1325 monozygotic twins, 1191 dizygotic twins (711 women from same-sex twin pairs and 480 women from opposite-sex twin pairs), 745 sisters of twins, and 218 spouses of male twins were evaluated. PCOS was defined as less than nine natural menstrual cycles a year combined with either hirsutism or acne. The prevalence of PCOS was compared using a ±2 test. Binary logistic regression analyses were conducted to test for confounding effects of smoking, age, and body mass index. Results: No significant differences in PCOS prevalence were found between women from same-sex twin pairs (either monozygotic or dizygotic), opposite-sex twin pairs, sisters, and spouses. Conclusion: The prevalence of PCOS is not different in women from opposite-sex and same-sex twin pairs, singleton sisters, or spouses. This indicates that possible androgen exposure of the female fetus, caused by a shared intrauterine environment with a male fetus, does not result in PCOS-like traits. Copyright © 2009 by The Endocrine Society
    corecore