bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic evidence that culling increases badger movement: implications for the spread of bovine tuberculosis
Authors: POPE LISA C. , BUTLIN ROGER K. , WILSON GAVIN J. , WOODROFFE ROSIE , ERVEN KRISTIEN , CONYERS CHRIS M. , FRANKLIN TANYA , DELAHAY RICHARD J. , CHEESEMAN CHRIS L. , BURKE TERRY 
Published: October 2007

AbstractThe Eurasian badger (Meles meles) has been implicated in the transmission of bovine tuberculosis (TB, caused byMycobacterium bovis) to cattle. However, evidence suggests that attempts to reduce the spread of TB among cattle in Britain by culling badgers have mixed effects. A large‐scale field experiment (the randomized badger culling trial, RBCT) showed that widespread proactive badger culling reduced the incidence of TB in cattle within culled areas but that TB incidence increased in adjoining areas. Additionally, localized reactive badger culling increased the incidence of TB in cattle. It has been suggested that culling‐induced perturbation of badger social structure may increase individual movements and elevate the risk of disease transmission between badgers and cattle. Field studies support this hypothesis, by demonstrating increases in badger group ranges and the prevalence of TB infection in badgers following culling. However, more evidence on the effect of culling on badger movements is needed in order to predict the epidemiological consequences of this control strategy. Here, analysis of the genetic signatures of badger populations in the RBCT revealed increased dispersal following culling. While standard tests provided evidence for greater dispersal after culling, a novel method indicated that this was due to medium‐ and long‐distance dispersal, in addition to previously reported increases in home‐range size. Our results also indicated that, on average, badgers infected withM. bovismoved significantly farther than did uninfected badgers. A disease control strategy that included culling would need to take account of the potentially negative epidemiological consequences of increased badger dispersal.
No relationship between individual genetic diversity and prevalence of avian malaria in a migratory kestrel
Authors: ORTEGO JOAQUÍN , CORDERO PEDRO J. , APARICIO JOSÉ MIGUEL , CALABUIG GUSTAU 
Published: October 2007

AbstractInsight into the genetic basis of malaria resistance is crucial for understanding the consequences of this parasite group on animal populations. Here, we analyse the relationship between genotypic variation at 11 highly variable microsatellite loci and prevalence of three different lineages of avian malaria, two Plasmodium (RTSR1, LK6) and one Haemoproteus (LK2), in a wild population of the endangered lesser kestrel (Falco naumanni). Although we used a large sample size (584 typed individuals), we did not find any significant association between the prevalence of the studied parasite lineages and individual genetic diversity. Although our data set is large, the 11 neutral markers typed may have had low power to detect such association, in part because of the low parasite prevalence observed (less than 5% of infected birds). However, the fact that we have detected previous correlations between genetic diversity and other traits (ectoparasitism risk, fecundity) in the study population using the same panel of neutral markers and lower sample sizes suggests that other factors could underlie the absence of such a similar correlation with avian malaria. Differences in the genetics of the studied traits and in their particular basis of inbreeding depression (dominance vs. overdominance) may have led to malaria prevalence, but not other traits, being uncoupled with individual genetic diversity. Also, we cannot discard the possibility that the absence of association was a consequence of a low pathogenic effect of these particular malaria lineages on our lesser kestrel population, and thus we should not expect the evolution of genetic resistance against these parasites.
Deep genetic divergences in Aoraki denticulata (Arachnida, Opiliones, Cyphophthalmi): a widespread ‘mite harvestman’ defies DNA taxonomy
Authors: BOYER SARAH L. , BAKER JESSICA M. , GIRIBET GONZALO 
Published: October 2007

Abstract Aoraki denticulata (Arachnida, Opiliones, Cyphophthalmi, Pettalidae), a widespread ‘mite harvestman’ endemic to the South Island of New Zealand, is found in leaf littler habitats throughout Nelson and Marlborough, and as far south as Arthur's Pass. We investigated the phylogeography and demographic history of A. denticulata in the first genetic population‐level study within Opiliones. A total of 119 individuals from 17 localities were sequenced for 785 bp of the gene cytochrome c oxidase subunit I; 102 of these individuals were from the Aoraki subspecies A. denticulata denticulata and the remaining 17 were from the subspecies A. denticulata major. An extraordinarily high degree of genetic diversity was discovered in A. denticulata denticulata, with average uncorrected p‐distances between populations as high as 19.2%. amova, average numbers of pairwise differences, and pairwise FST values demonstrated a significant amount of genetic diversity both within and between populations of this subspecies. Phylogenetic analysis of the data set revealed many well‐supported groups within A. denticulata denticulata, generally corresponding to clusters of specimens from single populations with short internal branches, but separated by long branches from individuals from other populations. No haplotypes were shared between populations of the widespread small subspecies, A. denticulata denticulata. These results indicate a subspecies within which very little genetic exchange occurs between populations, a result consistent with the idea that Cyphophthalmi are poor dispersers. The highly structured populations and deep genetic divergences observed in A. denticulata denticulata may indicate the presence of cryptic species. However, we find a highly conserved morphology across sampling localities and large genetic divergences within populations from certain localities, equivalent to those typically found between populations from different localities. Past geological events may have contributed to the deep genetic divergences observed between sampling localities; additionally, the high divergence within populations of A. denticulata denticulata suggests that the rate of COI evolution may be accelerated in this taxon. In contrast, the larger subspecies A. denticulata major shows much less differentiation between and within sampling localities, suggesting that it may disperse more easily than its smaller counterpart. The fact that the remarkable genetic divergences within populations of A. denticulata denticulata from certain localities are equivalent to divergences between localities poses a challenge to the rapidly spreading practice of DNA taxonomy
Patterns of genetic diversity and candidate genes for ecological divergence in a homoploid hybrid sunflower,Helianthus anomalus
Authors: SAPIR YUVAL , MOODY MICHAEL L. , BROUILLETTE LARRY C. , DONOVAN LISA A. , RIESEBERG LOREN H. 
Published: October 2007

AbstractNatural hybridization accompanied by a shift in niche preference by hybrid genotypes can lead to hybrid speciation. Natural selection may cause the fixation of advantageous alleles in the ecologically diverged hybrids, and the loci experiencing selection should exhibit a reduction in allelic diversity relative to neutral loci. Here, we analyzed patterns of genetic diversity at 59 microsatellite loci associated with expressed sequence tags (ESTs) in a homoploid hybrid sunflower species,Helianthus anomalus. We used two indices, ln RVand ln RH, to compare variation and heterozygosity (respectively) at each locus between the hybrid species and its two parental species,H. annuusandH. petiolaris. Mean values of ln RVand ln RHwere significantly lower than zero, which implies thatH. anomalusexperienced a population bottleneck during its recent evolutionary history. After correcting for the apparent bottleneck, we found six loci with a significant reduction in variation or with heterozygosity in the hybrid species, compared to one or both of the parental species. These loci should be viewed as a ranked list of candidate loci, pending further sequencing and functional analyses. Sequence data were generated for two of the candidate loci, but population genetics tests failed to detect deviations from neutral evolution at either locus. Nonetheless, a greater than eight‐fold excess of nonsynonymous substitutions was found near a putative N‐myristoylation motif at the second locus (HT998), and likelihood‐based models indicated that the protein has been under selection inH. anomalusin the past and, perhaps, in one or both parental species. Finally, our data suggest that selective sweeps may have united populations ofH. anomalusisolated by a mountain range, indicating that even low gene‐flow species may be held together by the spread of advantageous alleles.
Trans‐Arctic dispersals and the evolution of a circumpolar marine fish species complex, the capelin (Mallotus villosus)
Authors: DODSON JULIAN J. , TREMBLAY SUZY , COLOMBANI FRANÇOISE , CARSCADDEN JAMES E. , LECOMTE FREDERIC 
Published: October 2007

AbstractTrans‐Arctic dispersals and population and range expansions during the Pleistocene enhanced opportunities for evolutionary diversification and contributed to the process of speciation within the capelin, a northern marine‐fish complex exhibiting a circumpolar distribution. Capelin is composed of four highly divergent and geographically discrete mitochondrial DNA (mtDNA) clades (609 bp; cytochrome b). Two clades occur in the North Atlantic, one associated with Canadian Atlantic waters, including Hudson Bay, and the second distributed from West Greenland to the Barents Sea. Two additional clades occur in the Arctic and northeast Pacific Oceans, representing the most recent divergence within the capelin phylogenetic tree. Judged from mtDNA diversity, capelin populations comprising all clades experienced at least one demographic and spatial reduction–expansion episode during recent Pleistocene glaciations that imprinted their molecular architecture. The large contemporary populations in the northeast Pacific and Arctic Oceans exhibited significant genetic structure whereas no such structure was detected in the equally extensive North Atlantic clades. All clades are characterized by one or two prevalent mtDNA haplotypes distributed over the entire range of the clade. Assuming a Pacific ancestor for capelin, we infer that capelin dispersed on two separate occasions to the North Atlantic. A more recent event resulted in the isolation of eastern Pacific and Arctic clades, with the Arctic clade positioned for a potential third Atlantic invasion, as revealed by the presence of this clade in the Labrador Sea. The Labrador Sea is a potential contact zone for three of the four capelin clades.
Crystal structure of the Leishmania major phosphodiesterase LmjPDEB1 and insight into the design of the parasite‐selective inhibitors
Authors: Wang Huanchen , Yan Zier , Geng Jie , Kunz Stefan , Seebeck Thomas , Ke Hengming 
Published: October 2007

SummaryHuman leishmaniasis is a major public health problem in many countries, but chemotherapy is in an unsatisfactory state. Leishmania major phosphodiesterases (LmjPDEs) have been shown to play important roles in cell proliferation and apoptosis of the parasite. Thus LmjPDE inhibitors may potentially represent a novel class of drugs for the treatment of leishmaniasis. Reported here are the kinetic characterization of the LmjPDEB1 catalytic domain and its crystal structure as a complex with 3‐isobutyl‐1‐methylxanthine (IBMX) at 1.55 Å resolution. The structure of LmjPDEB1 is similar to that of human PDEs. IBMX stacks against the conserved phenylalanine and forms a hydrogen bond with the invariant glutamine, in a pattern common to most inhibitors bound to human PDEs. However, an extensive structural comparison reveals subtle, but significant differences between the active sites of LmjPDEB1 and human PDEs. In addition, a pocket next to the inhibitor binding site is found to be unique to LmjPDEB1. This pocket is isolated by two gating residues in human PDE families, but constitutes a natural expansion of the inhibitor binding pocket in LmjPDEB1. The structure particularity might be useful for the development of parasite‐selective inhibitors for the treatment of leishmaniasis.
IL‐12p40‐independent induction of protective immunity upon multiple Plasmodium berghei irradiated sporozoite immunizations
Authors: ROMERO J. F. , IBRAHIM G. H. , RENGGLI J. , HIMMELRICH H. , GRABER P. , CORRADIN G. 
Published: October 2007

SUMMARY Both IFN‐γ and IL‐12 play critical roles in defence against malaria. In a previous study, using Plasmodium yoelii model, C57BL/6 IFN‐γ receptor deficient mice (IFN‐γR−/–) failed to develop protective immunity after a single immunization with irradiated sporozoites, but were protected after multiple immunizations. In contrast, in another study, BALB/c IFN‐γ gene knockout mice (IFN‐γ−/–) and BALB/c IL‐12‐deficient mice (IL‐12p40−/– and IL‐12p35−/–) were unable to mount protective immune response even after multiple immunizations with the same irradiated parasites. To better define the role of IFN‐γ and IL‐12p40 in sterile protection, we selected the C57BL/6 model. Wild‐type and IL‐12p40−/– mice were immunized with a single or multiple doses of P. berghei irradiated sporozoites. While the wild‐type mice were able to rapidly produce IFN‐γ and mount a protective immune response after a single immunization with irradiated sporozoites, IL‐12p40−/– mice were neither able to produce IFN‐γ nor were protected. However, both strains of mice were able to produce IFN‐γ and were protected after three doses of irradiated sporozoites. Protection was partially and largely mediated by CD4+ T cells and CD8+ T cells, respectively. Thus, IL‐12p40 plays an important role in mediating early protection by irradiated sporozoite immunization but is dispensable for protective immunity induced by several immunizations with irradiated sporozoites. Moreover, treatment of hyperimmune IL‐12p40−/– mice with rhIL‐18 bp‐Fc, an inhibitor of IL‐18 activity, did not abrogate protection indicating that IL‐18 is not required for the effector phase of the immune response; it remains possible, however, that IL‐18 may compensate for the lack of IL‐12p40 in the induction phase of the immune response.
Comparison of immune responses in mice infected with different strains of Strongyloides venezuelensis
Authors: MACHADO E. R. , UETA M. T. , LOURENÇO E. V. , ANIBAL F. F. , ROQUE‐BARREIRA M. C. , FACCIOLI L. H. 
Published: October 2007

SUMMARY In human hosts and in murine models, the immune response to Strongyloides spp. is Th2 type. In addition, the profile of the host immune response follows various symptoms induced by Strongyloides spp. In the present study, we demonstrated that the L2 and L49 strains of Strongyloides venezuelensis obtained from Bolomys lasiurus and Nectomys squamipes induced significant and similar increases in eosinophil/mononuclear cell counts in the blood, peritoneal cavity fluid and bronchoalveolar lavage fluid when compared with uninfected mice. However, in the first 3 days of infection, IL‐4, IL‐5 and IFN‐γ levels were higher in the lungs of mice infected with the L2 strain, which also presented greater production of IgG and IgG1 than did mice infected with the L49 strain. The higher antibody and cytokine levels induced by the L2 strain correlated with a decrease in the number of female parasites recovered in the faeces of mice on post‐infection day 7. The results demonstrate that the L2 strain was a more potent stimulant of the humoral immune response, which can result in more efficient antibody‐dependent cell‐mediated cytotoxicity, a mechanism involved in eosinophil activation and parasite elimination. Further studies are needed in order to elucidate the molecular differences among parasites.
Determinants of memory in experimental filarial infections in mice
Authors: DASH Y. , RAMESH M. , GREINER D. , SHULTZ L. D. , KLEI T. R. , RAJAN T. V. 
Published: October 2007

SUMMARY In this communication, we examine the determinants and duration of memory responses against filarial parasites using an intraperitoneal mouse model of Brugia pahangi infection. We assessed the role of T cells in the memory response against B. pahangi larvae by transferring splenic T cells from wild‐type mice primed with L3 into T‐cell‐deficient mice. We found that mice reconstituted with primed T cells cleared intraperitoneal infections with infective larvae in an accelerated manner. To determine the components that may be responsible for the memory response, we transferred unfractionated T cells or purified CD4+ T cells or CD8+ T cells from BALB/cByJ mice primed a month earlier with L3 into T‐cell‐deficient BALB/c TCRβ−/– mice. Recipients were challenged 10 days after adoptive transfer. Our data demonstrated that while either CD4+ or CD8+ T cells are able to confer some level of protection, both are required for an optimal recall response. To evaluate the longevity of the memory response, we primed several groups of wild‐type mice at different times over a year. These mice were then challenged with a single injection of B. pahangi L3. The gap between the priming and second injections of larvae ranged between 4 and 60 weeks. We found that the memory responses in BALB/cByJ mice lasted over a year whereas those in C57BL/6 mice waned more rapidly.
The role of TNF‐α in Trichuris muris infection I: influence of TNF‐α receptor usage, gender and IL‐13
Authors: HAYES K. S. , BANCROFT A. J. , GRENCIS R. K. 
Published: October 2007

SUMMARY Th1 and Th2 responses to the gut‐dwelling nematode Trichuris muris have been well established in mouse models of infection, with Th2 responses clearly playing an important role in resistance. TNF‐α has previously been shown to play an undefined role in resistance, although it is not a typical Th2 cytokine. However, the relative importance of the two TNF‐α receptors, p55 and p75, has not previously been investigated. We demonstrate that p55 is the dominant TNF‐α receptor during T. muris infection as p55−/– mice are more susceptible to infection than p75−/– mice. Moreover, p75 clearly plays a role in negatively regulating TNF‐α. We also demonstrate that a gender difference influences the immune response of p55−/– and p75−/– mice in response to T. muris infection, with female mice fully expelling by day 35 post‐infection (p.i.) and male mice harbouring chronic infections. Further, this gender difference can be reversed with recombinant IL‐13 (rIL‐13) in male gene‐deficient mice or IL‐13R2.Fc treatment in female gene‐deficient mice.
Chlororespiration is involved in the adaptation of Brassica plants to heat and high light intensity
Authors: DÍAZ MILAGROS , DE HARO VIRGINIA , MUÑOZ ROMUALDO , QUILES MARÍA JOSÉ 
Published: October 2007

ABSTRACTTwo species of Brassica were used to study their acclimation to heat and high illumination during the first stages of development. One, Brassica fruticulosa, is a wild species from south‐east Spain and is adapted to both heat and high light intensity in its natural habitat, while the other, Brassica oleracea, is an agricultural species that is widely cultivated throughout the world. Growing Brassica plants under high irradiance and moderate heat was seen to affect the growth parameters and the functioning of the photosynthetic apparatus. The photosystem II (PSII) quantum yields and the capacity of photosynthetic electron transport, which were lower in B. fruticulosa than in B. oleracea, decreased in B. oleracea plants when grown under stress conditions, indicating inhibition of PSII. However, in B. fruticulosa, the values of these parameters were similar to the values of control plants. Photosystem I (PSI) activity was higher in B. fruticulosa than in B. oleracea, and in both species this activity increased in plants exposed to heat and high illumination. Immunoblot analysis of thylakoid membranes using specific antibodies raised against the NDH–K subunit of the thylakoidal NADH dehydrogenase complex (NADH DH) and against plastid terminal oxidase (PTOX) revealed a higher amount of both proteins in B. fruticulosa than in B. oleracea. In addition, PTOX activity in plastoquinone oxidation, and NADH DH activity in thylakoid membranes were higher in the wild species (B. fruticulosa) than in the agricultural species (B. oleracea). The results indicate that tolerance to high illumination and heat of the photosynthetic activity was higher in the wild species than in the agricultural species, suggesting that plant adaptation to these stresses in natural conditions favours subsequent acclimation, and that the chlororespiration process is involved in adaptation to heat and high illumination in Brassica.
Manipulation of light and CO2 environments of the primary leaves of bean (Phaseolus vulgaris L.) affects photosynthesis in both the primary and the first trifoliate leaves: involvement of systemic regulation
Authors: ARAYA TAKAO , NOGUCHI KO , TERASHIMA ICHIRO 
Published: October 2007

ABSTRACTPossible involvement of systemic regulation of the photosynthetic properties of young leaves by the local environments and/or photosynthate production of the mature leaves were examined using Phaseolus vulgaris plants. When primary leaves (PLs) were treated with air containing 150 µL CO2 L−1 with the other plant parts in ambient air at a photosynthetic photon flux density (PPFD) of 300 µmol photon m−2 s−1, decreases in the photosynthetic rate measured at 360 µL CO2 L−1 and a PPFD of 300 µmol photon m−2 s−1 (A360) were markedly retarded in both PLs and the first trifoliate leaves (TLs) as compared to plants treated with 400 µL CO2 L−1. Conversely, when PLs were treated with 1000 µL CO2 L−1, decreases in A360 were accelerated in both PLs and TLs. Shading of PLs accelerated the decrease in PL A360, and delayed the decrease in TLs. In the CO2 treatments, changes in A360 in TLs were mainly attributed to the changes in ribulose bisphosphate (RuBP) carboxylation rate, while the shading of PLs caused increases in both the RuBP carboxylation and regeneration rates in TLs. The ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco) activity on chlorophyll basis, an indicator of sun/shade acclimation, differed both among PLs and among TLs in accordance with the redox state of photosystem II (PSII) in PLs. Although carbohydrate contents of TLs were not affected by any manipulation of PLs, changes in the photosynthetic capacities of TLs acted to compensate for changes in PL photosynthesis. These results clearly indicate that the CO2 and shade treatments of PLs not only affect photosynthetic properties of the PLs themselves, but also systemically affected the photosynthetic properties of TLs. Possible roles of the redox state and photosynthate concentration in PLs in regulation of photosynthesis in PLs and TLs are discussed.