Population genetic diversity and structure of the pecan scab pathogen,Venturia effusa,on cv. Desirable and native seedlings,and the impact of marker number

Scab (Venturia effusa) is the major cause of economic loss in pecan in the south-eastern USA. We explored population genetic diversity and structure among orchards of cv. Desirable and native seedlings, and within-orchard variability among trees of all cultivars sampled. We compared the ability of 30, 15 and 7 previously developed microsatellites to characterize the population genetic diversity and structure of V. effusa. Analyses of molecular variance (AMOVA) provided little evidence of structure dependent on cultivar, but there was some evidence of structure between orchards of a cultivar based on distance. Individual orchard AMOVA showed that three of 11 orchards had between-tree population structure. Among six populations from cv. Desirable, a Mantel test showed that geographic distance was related to the pairwise genetic divergence (R² = 0.84). Among 11 orchards of various cultivars there was little difference in diversity using 30, 15 or 7 markers, or population structure based on AMOVA. Some minor differences in population structure were seen based on discriminant analysis of principal components, or dendrograms. Thus, depending on the objectives, future studies may use as few as 15 or 7 markers without losing ability to discern population genetic diversity or structure. More populations exhibited linkage disequilibrium when using 15 or 30 markers compared to when using seven markers. Knowledge of population genetics of V. effusa in relation to host genotype is needed to understand pathogen population interactions and gene flow, knowledge that will help underpin future breeding efforts to develop durable resistance in this long-lived orchard tree.     

Carlton: A new early tablestock potato variety

Carlton, an early sizing, oval, white-skinned potato variety was released by Agriculture Canada in 1982. Its tubers size as early as Warba making it suitable for the first early market, while its eyes are much shallower. Its yielding pattern was very similar to that of Warba when harvested at 75, 89 and 103 days from planting and to those of Norland and Norchip at maincrop harvest at a wide range of locations on the Canadian prairies. Boiling quality was similar to Warba while early chipping quality was better. No serious problem has been encountered in nearly twenty years of testing.     

3,4-Dihydroxyflavone acts as an antioxidant and antiapoptotic agent to support bovine embryo development in vitro

The effects of two antioxidants, superoxide dismutase (SOD) and the flavonoid 3,4-dihydroxyflavone (DHF), on bovine embryo development in vitro were examined. Blastocyst development, total cell and inner cell mass (ICM) numbers, intracellular levels of reactive oxygen species (ROS), apoptotic indices and gene expression levels were examined before and after treatment of day 2 bovine embryos (≥2-4 cells) with various concentrations of 3,4-DHF or SOD for 6 days. Statistical analysis was performed using analysis of variance, with significance defined at the P<0.05 level. SOD had no significant effect on bovine embryo development at any tested concentration (control, 32.8%; 300 U/ml, 33.9%; 600 U/ml, 24.2%). In contrast, 10 μM 3,4-DHF promoted higher blastocyst development (39.3%) than any other concentration (control, 26.7%; 1 μM, 30.3%; 50 μM, 29.5%; 100 μM, 20.5%). Compared with 300 U/ml SOD, 10 μM 3,4-DHF resulted in significantly higher blastocyst development (44.2%) (control, 31.5%; SOD 300 U/ml, 33.6%). Treatment with 3,4-DHF increased the ICM cell number and reduced intracellular ROS production and apoptotic cell numbers. When O(2) tension was decreased from 20% (high tension) to 5% (low tension), embryo development rates were doubled regardless of 3,4-DHF treatment. Under high O(2) tension, 10 μM 3,4-DHF treatment may render bovine embryo development similar to a low O(2) tension environment. The best blastocyst development was obtained under low O(2) tension plus 10 μM 3,4-DHF treatment. The relative expression levels of antioxidant (MnSOD), antiapoptotic (Survivin, Bax inhibitor) and growth-related genes (IFN-τ, Glut-5) were significantly increased after 3,4-DHF treatment, while the expression levels of oxidant (Sox) and apoptotic genes (Caspase-3 and Bax) were reduced. These results suggest that 3,4-DHF may promote the in vitro development of bovine embryos through its antioxidant and antiapoptotic effects.     

The use of embryonic stem cell derived bioactive material as a new protein supplement for the in vitro culture of bovine embryos

Embryonic stem (ES) cells are expanded versions of the inner cell mass cells that compose the early mammalian blastocyst. Components derived from ES cells may contain various bioactive materials (BM) helpful for early preimplantation embryo growth. In this study, we examined the effect of human ES cell derived BM (hES-BM) on in vitro culture of bovine embryos. When bovine parthenogenetic day 2 embryos were cultured in 10% hES-BM, a significantly higher embryo development rate (44.3%) and increased cell numbers were observed relative to control medium containing 3 mg/ml BSA (19.5%; P<0.01). Among the various concentrations (5, 10 and 15%) and days of treatment (2 or 4 days) tested, 10% hES-BM treatment for 4 days provided the best culture environment to support the growth of bovine embryos in vitro (P<0.05). Little difference was observed between 10% hES-BM and 10% FBS treatment in the examined parthenogenetic or in vitro fertilized embryos, although the hES-BM group developed at a slightly better rate. However, the ICM cell numbers were significantly higher in the hES-BM group in irrespective of embryo origin (P<0.05). In addition, the relative levels of pluripotency (Oct4, × 1.8 fold; Nanog. × 3.3 fold), embryogenesis (Stat3, × 2.8 fold; FGF4, × 18.8 fold; E-cad, × 2.0 fold) and growth (Glut5, × 2.6 fold) genes were significantly higher in the 10% hES-BM group than in the 10% FBS group (P<0.05), while the levels of other genes (Bax, Bcl2, MnSOD and Connexin43) were not different. This is the first report examining the positive effects of hES-BM on bovine embryo development in vitro. Based on our results, we conclude that hES-BM can be used as a new protein supplement for bovine preimplantation embryo development.     

Induction of inflammatory cytokines and toll-like receptors in chickens infected with avian H9N2 influenza virus

ABSTRACT: H9N2 influenza virus is endemic in many Asian countries and is regarded as a candidate for the next human pandemic. Knowledge of the induction of inflammatory responses and toll-like receptors (TLRs) in chickens infected with H9N2 is limited. Here, we show that H9N2 induces pro-inflammatory cytokines such as transforming growth factor-beta 3; tumor necrosis factor-alpha; interferon-alpha, -beta, and gamma; and TLR 1, 2, 3, 4, 5, 7, and 15 in trachea, lung, and intestine of infected chickens. In the lung, TLR-15 was dominantly induced. Taken together, it seems that H9N2 infections efficiently induce inflammatory cytokines and TLRs in trachea, lung and intestine of chickens.     

N-acetylserotonin increases cell proliferation and differentiating neuroblasts with tertiary dendrites through upregulation of brain-derived neurotrophic factor in the mouse dentate gyrus

In this study, we investigated the effects of N-acetylserotonin (NAS) on cell proliferation and neuroblast differentiation in the mouse dentate gyrus using anti-Ki67 and anti-doublecortin (DCX) antibodies. Ki67 is expressed in the nucleus or on the surface of chromosomes during all of the active phases of the cell cycle, and DCX is expressed in neuronal precursor cells as well as in immature neurons. At 17 weeks of age, 20 mg/kg of NAS or the same volume of vehicle was intraperitoneally administered once a day for 3 weeks. The animals were sacrificed 2 hr after the last vehicle or NAS treatment. NAS treatment significantly increased the number of Ki67-positive nuclei and DCX-immunoreactive neuroblasts with well-developed dendrites (tertiary dendrites) compared to the vehicle-treated group. However, the number of DCX-immunoreactive neuroblasts without tertiary dendrites was not changed. The administration of NAS also significantly increased the protein levels of brain-derived neurotrophic factor (BDNF) in the dentate gyrus. This result suggests that NAS significantly promotes cell proliferation and the number of differentiating neuroblasts with tertiary dendrites through an increase in BDNF levels in the mouse dentate gyrus.     

The ability of a topical novel combination of fipronil, amitraz and (S)-methoprene to protect dogs from Borrelia burgdorferi and Anaplasma phagocytophilum infections transmitted by Ixodes scapularis

Healthy, purpose-bred laboratory beagle dogs that had not been exposed to ticks and were seronegative for Borrelia burgdorferi and Anaplasma phagocytophilum were randomly assigned to four groups of eight dogs each. Control group 1 was not treated. Groups 2, 3 and 4 were treated with a single topical application of a new formulation of fipronil, amitraz and (S)-methoprene (CERTIFECT?, Merial Limited, GA, USA) at 28, 21 or 14 days prior to tick infestation, respectively. Each dog was infested with 25 female and 25 male field-collected adult Ixodes scapularis ticks that had infection rates of 66% for B. burgdorferi sensu stricto and 23% for A. phagocytophilum, as determined by polymerase chain reaction. Two and five days after tick infestation, control dogs had an average of 9.5 and 13.9 attached adult female ticks, respectively, whilst the 24 treated dogs remained tick-free aside from a single tick on the 2nd day after infestation. Serial serological tests demonstrated that the ticks successfully infected 8/8 control dogs with B. burgdorferi and co-infected 6/8 with A. phagocytophilum. B. burgdorferi infection also was confirmed in most control dogs by culture (6/8) and PCR (7/8) of skin biopsies. In contrast, CERTIFECT protected all 24 treated dogs against infection by both B. burgdorferi and A. phagocytophilum, as demonstrated by their negative serological tests throughout the study and the absence of any positive skin biopsy culture or PCR in these dogs.     

Seroprevalence of equine piroplasms in the Republic of Korea

Equine piroplasms include two tick-borne protozoan parasites, Babesia caballi and Theileria equi. Although no clinical equine piroplasmosis has been reported in the Republic of Korea, the possible existence of the disease has been proposed due to a nationwide distribution of the vector ticks. To determine if the antibodies against B. caballi and T. equi were present, 184 sera of horses (Equus caballus) raised in the Republic of Korea from 2007 to 2010 were assessed using cELISA kits. Two (1.1%) out of 184 sera were positive for T. equi, but none were seropositive for B. caballi. Both samples tested positive came from one region (Gyeonggi province). The accuracy of the cELISA was confirmed by PCR using primers specific to the 18S rRNA of T. equi. This study presents for the first time horses infected by T. equi in the Republic of Korea. Since the infection of T. equi occurred in horses raised in the Republic of Korea, further studies with continuous monitoring of the vector ticks for equine piroplasms and appropriate control programs need to be established.     

Evaluation of efficacy of a new live Salmonella Typhimurium vaccine candidate in a murine model

Efficacy of a new live Salmonella Typhimurium vaccine candidate attenuated by two virulence gene deletions was evaluated in this study. Live form of the vaccine was orally administered and formalin-inactivated form was intramuscularly (IM) administered. 105 female BALB/c mice were used and divided into 5 groups, A to E, containing 21 mice per group. Serum IgG and secretory IgA titers and levels of serum IFN-γ, IL-4, TNF-α, IL-12 of the immunized groups, especially group C (oral prime-oral booster) significantly increased. In addition, all animals in groups C showed no clinical symptoms and survived the virulent challenges, whereas all or some of mice from the other groups died of the challenge. These indicate that the vaccine candidate can be an effective tool for prevention of Salmonella infections by inducing robustly protective immune responses and leading to the production of inflammatory cytokines. Booster immunization, especially via oral administration, is necessary to optimize its protection.