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1.  Identification of Rotylenchulus reniformis Resistant Glycine Lines 
Journal of Nematology  2014;46(1):1-7.
Identification of resistance to reniform nematode (Rotylenchulus reniformis) is the first step in developing resistant soybean (Glycine max) cultivars that will benefit growers in the mid-South region of the United States. This study was conducted to identify soybean (G. max and G. soja) lines with resistance to this pathogen. Sixty-one wild and domestic soybean lines were evaluated in replicated growth chamber tests. Six previously untested soybean lines with useful levels of resistance to reniform nematode were identified in both initial screening and subsequent confirmation tests: released germplasm lines DS4-SCN05 (PI 656647) and DS-880 (PI 659348); accession PI 567516 C; and breeding lines DS97-84-1, 02011-126-1-1-2-1 and 02011-126-1-1-5-1. Eleven previously untested moderately susceptible or susceptible lines were also identified: released germplasm lines D68-0099 (PI 573285) and LG01-5087-5; accessions PI 200538, PI 416937, PI 423941, PI 437697, PI 467312, PI 468916, PI 594692, and PI 603751 A; and cultivar Stafford (PI 508269). Results of previously tested lines evaluated in the current study agreed with published reports 69.6% of the time for resistant lines and 87.5% of the time for susceptible lines. Soybean breeders may benefit from incorporating the newly identified resistant lines into their breeding programs.
PMCID: PMC3957566  PMID: 24643425
Glycine; reniform nematode; resistance; Rotylenchulus reniformis; soybean
2.  Characterisation of Host Growth after Infection with a Broad-Range Freshwater Cyanopodophage 
PLoS ONE  2014;9(1):e87339.
Freshwater cyanophages are poorly characterised in comparison to their marine counterparts, however, the level of genetic diversity that exists in freshwater cyanophage communities is likely to exceed that found in marine environments, due to the habitat heterogeneity within freshwater systems. Many cyanophages are specialists, infecting a single host species or strain; however, some are less fastidious and infect a number of different host genotypes within the same species or even hosts from different genera. Few instances of host growth characterisation after infection by broad host-range phages have been described. Here we provide an initial characterisation of interactions between a cyanophage isolated from a freshwater fishing lake in the south of England and its hosts. Designated ΦMHI42, the phage is able to infect isolates from two genera of freshwater cyanobacteria, Planktothrix and Microcystis. Transmission Electron Microscopy and Atomic Force Microscopy indicate that ΦMHI42 is a member of the Podoviridae, albeit with a larger than expected capsid. The kinetics of host growth after infection with ΦMHI42 differed across host genera, species and strains in a way that was not related to the growth rate of the uninfected host. To our knowledge, this is the first characterisation of the growth of cyanobacteria in the presence of a broad host-range freshwater cyanophage.
PMCID: PMC3906167  PMID: 24489900
3.  Functional characterisation of human cells harbouring a novel t(2p;7p) translocation involving TNS3 and EXOC6B genes 
BMC Medical Genetics  2013;14:65.
Tensin3 is an intracellular cytoskeleton-regulating protein, the loss of which is associated with increased cell motility, as has been observed in some human cancers. A novel chromosomal translocation, t(2;7)(p13;p12), present in a patient with a complex syndromic phenotype, directly involves Tensin3 (TNS3) and EXOC6B genes. This translocation could impair the expression of Tensin3 and ExoC6B proteins, and potentially produce two novel fusion transcripts. In the present study, we have investigated the expression and phenotypic features of these potential products in cultured cells from the proband.
Skin fibroblasts isolated from the proband as well as an age-matched control were grown in cell culture. Cells were used for quantitative RT-PCR, western blot and immunofluorescent confocal microscopy, which determined Tensin3 gene and protein expression. Phase-contrast and confocal microscopy additionally revealed cellular phenotype differences. A scratch wound assay monitored by live cell imaging measured cellular migration rates.
The levels of Tensin3 at both mRNA and protein levels were lower in proband cells versus control fibroblasts. Proband cells displayed broader and shorter morphologies versus control fibroblasts, and immunofluorescent staining revealed additional Tensin3 expression along cytoskeletal filaments and the cell periphery only in control fibroblasts. In addition, proband fibroblasts showed a significantly higher migration rate than control cells over 24 h.
The phenotypic changes observed in proband cells may arise from TNS3 haploinsufficiency, causing partial loss of full-length Tensin3 protein. These results further expose a role for Tensin3 in cytoskeletal organisation and cell motility and may also help to explain the syndromic features observed in the patient.
PMCID: PMC3728010  PMID: 23809228
Tensin; Exocyst; Translocation; Chimera; Haploinsufficiency; Cell migration
4.  Responses of nitrogen metabolism and seed nutrition to drought stress in soybean genotypes differing in slow-wilting phenotype1 
Recent advances in soybean breeding have resulted in genotypes that express the slow-wilting phenotype (trait) under drought stress conditions. The physiological mechanisms of this trait remain unknown due to the complexity of trait × environment interactions. The objective of this research was to investigate nitrogen metabolism and leaf and seed nutrients composition of the slow-wilting soybean genotypes under drought stress conditions. A repeated greenhouse experiment was conducted using check genotypes: NC-Roy (fast wilting), Boggs (intermediate in wilting); and NTCPR94-5157 and N04-9646 (slow-wilting, SLW) genotypes. Plants were either well-watered or drought stressed. Results showed that under well-watered conditions, nitrogen fixation (NF), nitrogen assimilation (NA), and leaf and seed composition differed between genotypes. Under drought stress, NF and NA were higher in NTCPR94-5157 and N04-9646 than in NC-Roy and Boggs. Under severe water stress, however, NA was low in all genotypes. Leaf water potential was significantly lower in checks (−2.00 MPa) than in the SLW genotypes (−1.68 MPa). Leaf and seed concentrations of K, P, Ca, Cu, Na, B were higher in SLW genotypes than in the checks under drought stress conditions. Seed protein, oleic acid, and sugars were higher in SLW genotypes, and oil, linoleic and linolenic acids were lower in SLW genotypes. This research demonstrated that K, P, Ca, Cu, Na, and B may be involved in SLW trait by maintaining homeostasis and osmotic regulation. Maintaining higher leaf water potential in NTCPR94-5157 and N04-9646 under drought stress could be a possible water conservation mechanism to maintain leaf turgor pressure. The increase in osmoregulators such as minerals, raffinose, and stachyose, and oleic acid could be beneficial for soybean breeders in selecting for drought stress tolerance.
PMCID: PMC3857554  PMID: 24339829
soybean; seed nutrition; seed composition; slow-wilting; drought tolerance
5.  Receptors for Hyaluronic Acid and Poliovirus: A Combinatorial Role in Glioma Invasion? 
PLoS ONE  2012;7(2):e30691.
CD44 has long been associated with glioma invasion while, more recently, CD155 has been implicated in playing a similar role. Notably, these two receptors have been shown closely positioned on monocytes.
Methods and Findings
In this study, an up-regulation of CD44 and CD155 was demonstrated in established and early-passage cultures of glioblastoma. Total internal reflected fluorescence (TIRF) microscopy revealed close proximity of CD44 and CD155. CD44 antibody blocking and gene silencing (via siRNA) resulted in greater inhibition of invasion than that for CD155. Combined interference resulted in 86% inhibition of invasion, although in these investigations no obvious evidence of synergy between CD44 and CD155 in curbing invasion was shown. Both siRNA-CD44 and siRNA-CD155 treated cells lacked processes and were rounder, while live cell imaging showed reduced motility rate compared to wild type cells. Adhesion assay demonstrated that wild type cells adhered most efficiently to laminin, whereas siRNA-treated cells (p<0.0001 for both CD44 and CD155 expression) showed decreased adhesion on several ECMs investigated. BrdU assay showed a higher proliferation of siRNA-CD44 and siRNA-CD155 cells, inversely correlated with reduced invasion. Confocal microscopy revealed overlapping of CD155 and integrins (β1, αvβ1 and αvβ3) on glioblastoma cell processes whereas siRNA-transfected cells showed consequent reduction in integrin expression with no specific staining patterns. Reduced expression of Rho GTPases, Cdc42, Rac1/2/3, RhoA and RhoB, was seen in siRNA-CD44 and siRNA-CD155 cells. In contrast to CD44-knockdown and ‘double’-knockdown cells, no obvious decrease in RhoC expression was observed in CD155-knockdown cells.
This investigation has enhanced our understanding of cell invasion and confirmed CD44 to play a more significant role in this biological process than CD155. Joint CD44/CD155 approaches may, however, merit further study in therapeutic targeting of infiltrating glioma cells.
PMCID: PMC3281850  PMID: 22363471
6.  Oseltamivir in human avian influenza infection 
Journal of Antimicrobial Chemotherapy  2010;65(Suppl 2):ii25-ii33.
Avian influenza A viruses continue to cause disease outbreaks in humans, and extrapulmonary infection is characteristic. In vitro studies demonstrate the activity of oseltamivir against avian viruses of the H5, H7 and H9 subtypes. In animal models of lethal infection, oseltamivir treatment and prophylaxis limit viral replication and improve survival. Outcomes are influenced by the virulence of the viral strain, dosage regimen and treatment delay; it is also critical for the compound to act systemically. Observational data on oseltamivir treatment in the early stages of disease suggest it is useful for improving survival in patients infected with H5 viruses, and drug-selected resistance has only rarely been reported. The WHO strongly recommends oseltamivir for the treatment of confirmed or suspected cases of human H5 infection and prophylaxis of those at high risk of infection. In addition to oral dosing, nasogastric administration appears to be a viable option for the management of severely ill patients, as is the use of higher doses and prolonged schedules. F. Hoffmann-La Roche Ltd, the manufacturer of oseltamivir, is developing a mathematical model to allow rapid prediction of appropriate dosage regimens for any future pandemic. Roche is also funding the Avian Influenza Registry, an online database that aims to collect information from clinicians worldwide on the course of avian influenza in humans.
PMCID: PMC2835509  PMID: 20215132
H5N1; treatment; prophylaxis; clinical; pre-clinical
7.  A Randomized, Crossover Study to Evaluate the Pharmacokinetics of Amantadine and Oseltamivir Administered Alone and in Combination 
PLoS ONE  2007;2(12):e1305.
The threat of potential pandemic influenza requires a reevaluation of licensed therapies for the prophylaxis or treatment of avian H5N1 infection that may adapt to man. Among the therapies considered for use in pandemic influenza is the co-administration of ion channel and neuraminidase inhibitors, both to potentially increase efficacy as well as to decrease the emergence of resistant isolates. To better understand the potential for drug interactions, a cross-over, randomized, open-label trial was conducted with amantadine, 100 mg po bid, and oseltamivir, 75 mg po bid, given alone or in combination for 5 days. Each subject (N = 17) served as their own control and was administered each drug alone or in combination, with appropriate wash-out. Co-administration with oseltamivir had no clinically significant effect on the pharmacokinetics (PK) of amantadine [mean ratios (90% CI) for AUC0-12 0.93 (0.89, 0.98) and Cmax 0.96 (0.90, 1.02)]. Similarly, amantadine co-administration did not affect oseltamivir PK [AUC0-12 0.92 (0.86, 0.99) and Cmax 0.85 (0.73, 0.99)] or the PK of the metabolite, oseltamivir carboxylate [AUC0-12 0.98 (0.95, 1.02) and Cmax 0.95 (0.89, 1.01)]. In this small trial there was no evidence of an increase in adverse events. Although many more subjects would need to be studied to rule out a synergistic increase in adverse events, the combination in this small human drug-drug interaction trial appears safe and without pharmacokinetic consequences.
Trial Registration NCT00416962
PMCID: PMC2110886  PMID: 18074029
8.  Stockpiling oseltamivir 
BMJ : British Medical Journal  2005;331(7526):1203.
PMCID: PMC1285143  PMID: 16293852
9.  MRG15 Regulates Embryonic Development and Cell Proliferation 
Molecular and Cellular Biology  2005;25(8):2924-2937.
MRG15 is a highly conserved protein, and orthologs exist in organisms from yeast to humans. MRG15 associates with at least two nucleoprotein complexes that include histone acetyltransferases and/or histone deacetylases, suggesting it is involved in chromatin remodeling. To study the role of MRG15 in vivo, we generated knockout mice and determined that the phenotype is embryonic lethal, with embryos and the few stillborn pups exhibiting developmental delay. Immunohistochemical analysis indicates that apoptosis in Mrg15−/− embryos is not increased compared with wild-type littermates. However, the number of proliferating cells is significantly reduced in various tissues of the smaller null embryos compared with control littermates. Cell proliferation defects are also observed in Mrg15−/− mouse embryonic fibroblasts. The hearts of the Mrg15−/− embryos exhibit some features of hypertrophic cardiomyopathy. The increase in size of the cardiomyocytes is most likely a response to decreased growth of the cells. Mrg15−/− embryos appeared pale, and microarray analysis revealed that α-globin gene expression was decreased in null versus wild-type embryos. We determined by chromatin immunoprecipitation that MRG15 was recruited to the α-globin promoter during dimethyl sulfoxide-induced mouse erythroleukemia cell differentiation. These findings demonstrate that MRG15 has an essential role in embryonic development via chromatin remodeling and transcriptional regulation.
PMCID: PMC1069611  PMID: 15798182
10.  Host Suitability of Diverse Lines of Phaseolus vulgaris to Multiple Populations of Heterodera glycines 
Journal of Nematology  2003;35(1):23-28.
The host suitability of diverse races and gene pools of common bean (Phaseolus vulgaris) for multiple isolates of Heterodera glycines was studied. Twenty P. vulgaris genotypes, representing three of the six races within the two major germplasm pools, were tested in greenhouse experiments to determine their host suitability to five H. glycines isolates. Phaseolus vulgaris genotypes differed in their host suitability to different H. glycines isolates. While some common bean lines were excellent hosts for some H. glycines isolates, no common bean line was a good host for all isolates. Some bean lines from races Durango and Mesoamerica, representing the Middle America gene pool, were resistant to all five nematode isolates. Other lines, from both the Andean and Middle America gene pools, had differential responses for host suitability to the different isolates of H. glycines.
PMCID: PMC2620605  PMID: 19265970
common bean; Heterodera glycines; host suitability; Phaseolus vulgaris; race; resistance; soybean cyst nematode
11.  Molecular Basis for Impaired Muscle Differentiation in Myotonic Dystrophy 
Molecular and Cellular Biology  2001;21(20):6927-6938.
Differentiation of skeletal muscle is affected in myotonic dystrophy (DM) patients. Analysis of cultured myoblasts from DM patients shows that DM myoblasts lose the capability to withdraw from the cell cycle during differentiation. Our data demonstrate that the expression and activity of the proteins responsible for cell cycle withdrawal are altered in DM muscle cells. Skeletal muscle cells from DM patients fail to induce cytoplasmic levels of a CUG RNA binding protein, CUGBP1, while normal differentiated cells accumulate CUGBP1 in the cytoplasm. In cells from normal patients, CUGBP1 up-regulates p21 protein during differentiation. Several lines of evidence show that CUGBP1 induces the translation of p21 via binding to a GC-rich sequence located within the 5′ region of p21 mRNA. Failure of DM cells to accumulate CUGBP1 in the cytoplasm leads to a significant reduction of p21 and to alterations of other proteins responsible for the cell cycle withdrawal. The activity of cdk4 declines during differentiation of cells from control patients, while in DM cells cdk4 is highly active during all stages of differentiation. In addition, DM cells do not form Rb/E2F repressor complexes that are abundant in differentiated cells from normal patients. Our data provide evidence for an impaired cell cycle withdrawal in DM muscle cells and suggest that alterations in the activity of CUGBP1 causes disruption of p21-dependent control of cell cycle arrest.
PMCID: PMC99869  PMID: 11564876

Results 1-11 (11)