Abundance of biting midge species (Diptera: Ceratopogonidae,Culicoides spp.) on cattle farms in Korea

Culicoides biting midges were collected on three cattle farms weekly using light traps overnight from May to October between 2010 and 2011 in the southern part of Korea. The seasonal and geographical abundance of Culicodes spp. were measured. A total of 16,538 biting midges were collected from 2010 to 2011, including seven species of Culicoides, four of which represented 98.42% of the collected specimens. These four species were Culicodes (C.) punctatus (n = 14,413), C. arakawae (n = 1,120), C. oxystoma (n = 427), and C. maculatus (n = 318). C. punctatus was the predominant species (87.15%).     

Protective effect of butylated hydroxylanisole against hydrogen peroxide-induced apoptosis in primary cultured mouse hepatocytes

Butylated hydroxyanisole (BHA) is a synthetic phenolic compound consisting of a mixture of two isomeric organic compounds: 2-tert-butyl-4-hydroxyanisole and 3-tert-butyl-4-hydroxyanisole. We examined the effect of BHA against hydrogen peroxide (H₂O₂)-induced apoptosis in primary cultured mouse hepatocytes. Cell viability was significantly decreased by H₂O₂ in a dose-dependent manner. Additionally, H₂O₂ treatment increased Bax, decreased Bcl-2, and promoted PARP-1 cleavage in a dose-dependent manner. Pretreatment with BHA before exposure to H₂O₂ significantly attenuated the H₂O₂-induced decrease of cell viability. H₂O₂ exposure resulted in an increase of intracellular reactive oxygen species (ROS) generation that was significantly inhibited by pretreatment with BHA or N-acetyl-cysteine (NAC, an ROS scavenger). H₂O₂-induced decrease of cell viability was also attenuated by pretreatment with BHA and NAC. Furthermore, H₂O₂-induced increase of Bax, decrease of Bcl-2, and PARP-1 cleavage was also inhibited by BHA. Taken together, results of this investigation demonstrated that BHA protects primary cultured mouse hepatocytes against H₂O₂-induced apoptosis by inhibiting ROS generation.     

Quantification of the transmission of classical swine fever virus between herds during the 1997-1998 epidemic in The Netherlands

In this study, we describe a method to quantify the transmission of Classical Swine Fever Virus (CSFV) between herds from data collected during the 1997–1998 epidemic in the Netherlands. From the contacts between infected herds and the serological findings shortly before depopulation, we estimated the week of virus introduction and the length of the period over which the herd emitted virus for each CSFV-infected herd. From these data, we estimated the infection-rate parameter β (the average number of herds infected by one infectious herd during one week) and the herd reproduction ratio, R_h (the average total number of secondary outbreaks caused by one infectious herd, i.e. in its entire infectious period), using a SIR-model for different sets of CSF control measures. When R_h > 1, an epidemic continues to grow. On the other hand, when R_h < 1 an epidemic will fade out.

During the phase before the first outbreak was diagnosed and no specific measures had been implemented, β was estimated at 1.09 and R_h at 6.8. In the subsequent phase infected herds were depopulated, movement restrictions were implemented, infected herds were traced forward and backward and the herds in the protection and surveillance zones were clinically inspected by the veterinary authorities (regional screening). This set of measures significantly reduced β to 0.38. However, R_h was 1.3 and thus still >1. Consequently, the number of outbreaks continued to grow. After a number of additional measures were implemented, the value of R_h was reduced to 0.5 and the epidemic came to an end. These measures included pre-emptive slaughter of herds that had been in contact with infected herds or were located near an infected herd, increased hygienic procedures, replacement of transports of pigs for welfare reasons by killing of young piglets and a breeding ban, and regional screening for CSF-infected herds by local veterinary practitioners.     

Evidence of a pluripotent human embryonic stem cell line derived from a cloned blastocyst

Somatic cell nuclear transfer (SCNT) technology has recently been used to generate animals with a common genetic composition. In this study, we report the derivation of a pluripotent embryonic stem (ES) cell line (SCNT-hES-1) from a cloned human blastocyst. The SCNT-hES-1 cells displayed typical ES cell morphology and cell surface markers and were capable of differentiating into embryoid bodies in vitro and of forming teratomas in vivo containing cell derivatives from all three embryonic germ layers in severe combined immunodeficient mice. After continuous proliferation for more than 70 passages, SCNT-hES-1 cells maintained normal karyotypes and were genetically identical to the somatic nuclear donor cells. Although we cannot completely exclude the possibility that the cells had a parthenogenetic origin, imprinting analyses support a SCNT origin of the derived human ES cells.     

Application of the rpoS gene for the detection of Vibrio anguillarum in flounder and prawn by polymerase chain reaction

Vibrio anguillarum , an opportunistic fish pathogen, is the main species responsible for vibriosis, a disease that affects feral and farmed fish and shellfish, and causes considerable economic losses in marine aquaculture. In this study, we used polymerase chain reaction (PCR) to detect V. anguillarum . PCR specificity was evaluated by amplifying the rpoS gene, a general stress regulator, in six strains of V. anguillarum and 36 other bacterial species. PCR amplified a species-specific fragment (689 bp) from V. anguillarum . Furthermore, the PCR assay was sensitive enough to detect rpoS expression from 3 pg of genomic DNA , or from six colony-forming units (CFU) mL⁻¹ of cultured V. anguillarum . However, the assay was less sensitive when genomic DNA from the infected flounder and prawn was used (limit of detection, 50 ng and 10 ng g⁻¹ tissue, respectively). These data demonstrate that PCR amplification of the rpoS gene is a sensitive and species-specific method to detect V. anguillarum in practical situations.     

Characterization of 12 Novel Microsatellite Markers of Sogatella furcifera (Hemiptera: Delphacidae) Identified From Next-Generation Sequence Data

The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is a major pest of rice and has long-range migratory behavior in Asia. Microsatellite markers (simple sequence repeats) have been widely used to determine the origins and genetic diversity of insect pests. We identified novel microsatellite loci for S. furcifera samples collected from Laos, Vietnam, and three localities in Bangladesh from next-generation Roche 454 pyrosequencing data. Size polymorphism at 12 microsatellite loci was verified for 40 adult individuals collected from Shinan, South Korea. The average number of alleles per locus was 7.92. The mean values of observed (H_o) and expected heterozygosities (H_E) were 0.615 and 0.757, respectively. These new microsatellite markers will be a resource for future ecological genetic studies of S. furcifera samples across more broad geographic regions in Asia and may assist in estimations of genetic differentiation and gene flow among populations for implementation of more effective management strategies to control this serious rice pest.     

苏云金芽胞杆菌新菌株的研究

为筛选对昆虫有高力的苏云金芽胞杆菌特异性菌株,从韩国不同地区土壤中筛选出两株对鳞翅目和双翅目昆虫具有杀虫活性的苏云金芽胞杆菌菌株K9805和K9903,它们分属于苏云金芽胞杆菌库斯塔克亚种和鲇泽亚种,形成典型的双金字塔型伴胞晶体,两菌株不但对小菜蛾、甜菜夜蛾具有较高的生命活性,而且对双翅目昆虫致倦库蚊有毒。K9805含有cry IAa,cy IAb,cry IC,cry ID和cry I基因,K9903含有cry IAa,cry IAb,cry IAc,cry IE和cry Ⅱ基因。     

韩国土壤中苏云金芽孢杆菌菌株的分离和鉴定

从韩国不同地区采集的６２０个土壤样品中分离出６７株苏云金芽孢杆菌,分属于１０种不同的血清型,毒力测定结果表明,在６７株分离株中,３５．８２％的菌株对鳞翅目昆虫具有生物活性,２２．３９％的菌株对双翅目昆虫有毒,３２．８４％的菌株对鳞翅目和双翅目昆虫都具有杀虫活性,８．９５％的菌株为没有杀虫活性的无毒菌株,其中对鳞翅目昆虫有毒的菌株产生典型双金字塔形伴孢晶体对双翅目昆虫有毒的菌株和无毒菌株都产生球形伴     

Limit of colour vision in dim light in larvae of the giant freshwater prawn <Emphasis Type="Italic">Macrobrachium rosenbergii</Emphasis>

Colour vision depends on sufficient ambient light and becomes ineffective at a particular low light intensity. It is not known how decapod crustaceans see colour in dim light. In the present study we investigated the colour vision threshold in larvae of the giant freshwater prawn Macrobrachium rosenbergii in a tank under natural illumination. Plastic beads of different colours (blue, red, yellow and white) in various combinations were suspended in the tank. The larvae swam straight toward the beads and gathered around them. The number of larvae was highest on the blue and white beads. The luminance in the tank was then gradually decreased by covering it with different numbers of layers of black cloth, and the response of the larvae to the beads was video-recorded under infrared illumination. The preference for blue and white beads remained manifest as the luminance was reduced from 418 to 0.07 cd/m², but not at 0.02 cd/m², indicating a colour vision threshold between 0.07 and 0.02 cd/m². The larvae have apposition compound eyes with large optical parameters, comparable to those of apposition eyes of nocturnal insects, which presumably capture more light and show enhanced sensitivity, enabling the larvae to see colour in dim light.