Combined use of a synthetic trail pheromone and insecticidal bait provides effective control of an invasive ant

BACKGROUND: Except for sex pheromones, use of pheromones in pest management has been largely unexplored. A high concentration of trail pheromone disrupts ant trail following and foraging, and thus synthetic trail pheromone can be a novel control agent for pest ants. In this study, a year‐long treatment of small areas (100 m² plots of urban house gardens) with synthetic trail pheromone, insecticidal bait or both was conducted to develop a novel control method of the invasive Argentine ant Linepithema humile (Mayr). RESULTS: The ant population could be maintained lower than or similar to the initial level only by combined treatment with synthetic trail pheromone and insecticidal bait. Actually, the ant population was nearly always lowest in combination treatment plots. Throughout the study period, the ant population in plots treated with either one of synthetic trail pheromone or insecticidal bait remained similar to no‐treatment plots. CONCLUSIONS: Combination treatment may be a more effective and environmentally friendly method for controlling invasive ants than conventional methods. Extermination of ants by insecticidal bait and inhibition of re‐infestation by pheromone may be the mechanism of the combination effect. This is the first study to show a significant effect of synthetic trail pheromone on ant population. Copyright © 2011 Society of Chemical Industry     

Identification of novel genetic markers and evaluation of genetic structure in a population of Japanese crested ibis

Japanese population of the Japanese crested ibis Nipponia nippon was founded by five individuals gifted from the People's Republic of China. In order to exactly evaluate genetic structure, we first performed development of novel genetic makers using 89 microsatellite primer pairs of related species for cross‐amplification. Of these, only three primer pairs were useful for the genetic markers. Additionally, we sequenced allelic PCR products of these three markers together with 10 markers previously identified. Most markers showed typical microsatellite repeat units, but two markers were not simple microsatellites. Moreover, over half of the markers did not have the same repeat units as those of the original species. These results suggested that development of novel genetic markers in this population by cross‐amplification is not efficient, partly because of low genetic diversity. Furthermore, the cluster analysis by STRUCTURE program using 17 markers showed that the five founders were divided into two clusters. However, the genetic relationships among the founders indicated by the clustering seemed to be questionable, because the analysis relied largely on a small number of triallelic markers, in spite of the addition of the three useful markers. Therefore, more efficient methods for identifying large numbers of single nucleotide polymorphisms are desirable.     

Origin of host-specificity resistance genes of common wheat against non-adapted pathotypes of Pyricularia oryzae inferred from D-genome diversity in synthetic hexaploid wheat lines

Journal of General Plant Pathology - Wheat resistance genes Rwt3 and Rwt4 constitute a host-specificity barrier against non-wheat pathotypes of the blast fungus, Pyricularia oryzae. To understand...     

Brainstem Auditory Evoked Responses Elicited by Tone-Burst Stimuli in Clinically Normal Dogs

Brainstem auditory evoked responses (BAERs) to click and tone-burst stimuli (0.5, 1, 2, 4, and 8 kHz) were recorded from 32 ears in 16 adult Beagles. BAERs were used to establish a normative database and describe response thresholds and latencies (wave I-IV) for the different stimuli. The frequencies of sound used were 8, 4, 2, 1, and 0.5 kHz. Sound stimuli were delivered by a closed headphone and masking stimuli were not applied. The BAER waveforms obtained were similar to those reported previously, except for a frequency-following response evoked by 1-kHz tone-bursts. The threshold was lowest when clicks and 4-kHz tone-bursts were used. Significant differences were observed between the mean values of the peak latencies for clicks and 4-and 8-kHz tone-bursts. The tone-burst stimulation used in our experiment was shown to be an appropriate method for detecting the BAERs. Thus, for investigating the frequency-specificity of the auditory sense, BAER data obtained using tone-burst sound in dogs may be meaningful.     

Meiotic resumption of porcine immature oocytes is prevented by ooplasmic Gsalpha functions

A high cyclic adenosine monophosphate (cAMP) level in fully-grown immature oocytes prevents meiotic resumption. In Xenopus, inhibitory cAMP is synthesized within oocytes depending on a stimulatory alpha-subunit of G-protein (Gsalpha). In the present study, we examined whether ooplasmic Gsalpha is involved in meiotic arrest of porcine oocytes. First, we studied the presence of Gsalpha molecules in porcine oocytes by immunoblotting, and this suggested the presence of reported isoforms (45 and 48 kDa) not only in cumulus cells but also in porcine oocytes. Then we injected an anti-Gsalpha antibody into porcine immature oocytes and found that inhibition of ooplasmic Gsalpha functions significantly promoted germinal vesicle breakdown of the oocytes, whose spontaneous meiotic resumption was prevented by 3-isobutyl-l-methylxanthine (IBMX) treatment. Although cyclin B synthesis and M-phase promoting factor (MPF) activation were largely prevented until 30 h of culture in IBMX-treated oocytes, injection of anti-Gsalpha antibody into these oocytes partially recovered cyclin B synthesis and activated MPF activity at 30 h. These results suggest that meiotic resumption of porcine oocytes is prevented by ooplasmic Gsalpha, which may stimulate cAMP synthesis within porcine oocytes, and that synthesized cAMP prevents meiotic resumption of oocytes through the signaling pathways involved in MPF activation.     

Rwt4 , a wheat gene for resistance to Avena isolates of Magnaporthe oryzae , functions as a gene for resistance to Panicum isolates in Japan

Rwt4 (synonym of Rmg1), a temperature-insensitive gene for resistance to Avena isolates of Magnaporthe oryzae, was identified in wheat cultivar Norin 4 in a seedling assay. The significance of Rwt4 was evaluated using flag leaves of wheat cultivars. At high temperature, Norin 4 was completely resistant to Avena isolate Br58, while Chinese Spring, a noncarrier of Rwt4, was susceptible. Genetic analysis of F₂ plants derived from Norin 4 × Chinese Spring indicated that the resistance of flag leaves of Norin 4 to the Avena isolate is conditioned by a single major gene. Segregation analysis of F₃ seedlings derived from the F₂ plants showed that the major gene is actually Rwt4. These results suggest that Rwt4 is effective against Avena isolates throughout the growth stages. Furthermore, screening of Pyricularia isolates from various hosts suggested that Panicum isolates are possible carriers of the corresponding avirulence gene, PWT4. Segregation analyses of F₂ and F₃ seedlings showed that Panicum isolates actually carry PWT4, and, therefore, that Rwt4 is also effective against Panicum isolates. On the other hand, none of the Oryza, Setaria, Triticum, and Lolium isolates tested was a carrier of PWT4. The significance of this finding is discussed from the viewpoint of epidemics of blast disease on wheat.     

Measurement of polynuclear aromatic hydrocarbons in canine lung after alkaline decomposition

An alkaline decomposition method employing a KOH/alcohol solution was studied, and polynuclear aromatic hydrocarbons (PAHs) contained in particles remaining in canine lung were measured. As a result, BaA, BkF, BaP, and BghiP were found. By this method, PAHs extracted from the lungs of 32 dogs were 13.0-166.0 ng (mean, 63.0 ng) for BaA, 6.6-90.2 ng (mean, 27.4 ng) for BkF, 9.8-167.4 ng (mean 47.2 ng) for BaP, and 10.8-206.0 ng (mean, 61.8 ng) for BghiP. The results showed no correlation between the age and the concentration of PAHs in the lung, but some correlation was found between the age and the lung weight (p<0.01). There were significant correlations among the concentrations of the compounds in the lung (p<0.01). These results suggest that dogs, like humans, are affected by automobile exhaust and other common generation sources of such substances.     

Comparison of Pathogenicity and Nucleotide Sequences of 3′-terminal Regions of Bean yellow mosaic virus Isolates from Gladiolus

Sixty-four isolates of Bean yellow mosaic virus (BYMV) from cultivated and naturalized gladioli were divided into two pathogenic groups, necrotic spot (NS) and chlorotic spot (CS) groups on Chenopodium quinoa. NS-type isolates (S-22N and E-24N), CS-type isolates (S-22C and E-92C), and broad bean isolates (Sb-50C and Sb-12C) differed in their pathogenicity on Antirrhinum majus, Nicotiana benthamiana, Phaseolus vulgaris, Spinacia oleracea and Vigna unguiculata. The four gladiolus isolates were different from BYMV-B, -P, -O and C1YVV-N in their pathogenicity on these plants, while the two broad bean isolates were similar to BYMV-B, originally from broad bean. The nucleotide (nt) sequences of the 3′-terminal region of the BYMV RNA genome of the two NS-type isolates, the two CS-type isolates, the two broad bean isolates and BYMV-B, -P and -O were determined. In a phylogenetic tree based on the CP amino acid (aa) sequences, the two NS-type isolates clustered together (identity 98.4% and 98.2% at the nt and aa level, respectively). The two CS-type isolates clustered with BYMV-O (93.2 to 99.3% nt identity and 95.6 to 98.5% aa identity). The two broad bean isolates clustered with BYMV-B (99.0 to 99.5% nt identity and 98.9 to 99.6% aa identity). BYMV-P clustered with BYMV-CS (identity 97.7% and 99.3% at the nt and aa level, respectively). The obtained sequences were compared with those of the 3′-terminal regions of seven published BYMV isolates. In a phylogenetic tree based on deduced aa sequences, BYMV isolates were divided into four clusters. Received 1 July 1999/ Accepted in revised form 22 May 2000     

Effect of L‐carnitine on proliferative response and mRNA expression of some of its associated factors in splenic mononuclear cells of male broiler chicks

The effect of L‐carnitine supplementation on mitogen (concanavalin A, Con A) induced proliferation of mononuclear cells (MNC) in the spleen was investigated in broiler chickens at different ages. Day‐old chickens were fed a diet supplemented with or without L‐carnitine (100 ppm) for 24 days. The carnitine‐supplemented group showed greater proliferation of MNC in the spleen in response to Con A than that of the control group at 24 days of age. In addition, at 24 days of age the carnitine‐supplemented group showed higher expression of interleukin (IL)‐2 and interferon (IFN)‐γ mRNA, but lower expression of inducible nitric oxide synthase (iNOS) in the Con A‐stimulated splenic MNC than the control group. The enhancement effect of L‐carnitine on MNC proliferation and IL‐2 mRNA expression was not found in chicks at 14 days of age. Addition of L‐carnitine (50 nmol/mL) to the culture medium enhanced proliferation and IL‐2 mRNA expression of splenic MNC obtained from 24‐day‐old but not from 14‐day‐old broiler chickens. The results suggest that L‐carnitine is capable of enhancing MNC proliferation in broiler chickens at 24 days of age partly through increasing IL‐2 and IFN‐γ production and decreasing NO production.     

Effect of dietary supplementation of astaxanthin from Phaffia rhodozyma on lipopolysaccharide‐induced early inflammatory responses in male broiler chickens (Gallus gallus) fed a corn‐enriched diet

Effect of dietary supplementation of astaxanthin (Ax) from Phaffia rhodozyma on lipopolysaccharide‐induced inflammatory responses was investigated in male broiler chickens fed a corn‐based diet. Birds (1 week of age) were fed a corn‐enriched diet containing either 0 or 100 ppm Ax for 2 weeks and were intraperitoneally injected with lipopolysaccharide (LPS, 1 mg/kg body weight). Inflammatory responses were evaluated by determining changes in expression of messenger RNA (mRNA) in cytokines and mediators related to inflammatory responses (interleukin (IL)‐1 beta and ‐6, inducible nitrite synthase (iNOS), interferon (IFN)‐ γ and cyclooxygenase (Cox)‐2 in the liver and spleen after 2 h of LPS injection and plasma ceruloplasmin concentration as an acute phase protein. Birds fed Ax showed significantly higher iNOS mRNA expression in the liver and spleen compared to that of control birds. Ax‐fed birds also showed greater increase in mRNA expression in the liver of IL‐1, IL‐6 and IFN‐γ compared to that of control birds. The enhancing effect of Ax was further progressed when LPS was injected. No difference was found in plasma ceruloplasmin concentration between the Ax‐fed group and control group. The results suggest that feeding supplementation of Ax (100 ppm) to a corn‐enriched diet possibly does not have anti‐inflammatory effect in male broiler chickens.