Resistance levels of sulfonylurea‐resistant Schoenoplectus juncoides (Roxb.) Palla with various Pro197 mutations in acetolactate synthase to imazosulfuron,bensulfuron‐methyl,metsulfuron‐methyl and imazaquin‐ammonium

An investigation, using herbicidal pot tests in a greenhouse condition, was conducted to determine the whole‐plant dose–response relationships to several acetolactate synthase (ALS)‐inhibiting herbicides of sulfonylurea (SU)‐resistant Schoenoplectus juncoides with various Pro₁₉₇ mutations in ALS that was collected from Japanese rice paddy fields. All the tested SU‐resistant accessions with a Pro₁₉₇ mutation were highly resistant to two commonly used SU herbicides (imazosulfuron and bensulfuron‐methyl), but were much less resistant to another SU herbicide, metsulfuron‐methyl, and were substantially not resistant to imazaquin‐ammonium. These cross‐resistance patterns have been known previously in fragments of S. juncoides and other weed species and were comprehensively confirmed in this study with a whole set of Pro₁₉₇ mutations. The analyses of resistance levels, based on ED₉₀ values, newly showed that different accessions with a common amino acid substitution in ALS1 showed similar responses to these herbicides (confirmed with four amino acid substitutions), that the rankings of resistance levels that were conferred by various Pro₁₉₇ mutations in ALS1 differed among the SU herbicides and that the resistance levels of the ALS2‐mutated accessions were higher than, lower than or similar to those of the corresponding ALS1‐mutated accessions, depending on the compared pair, but the deviation patterns were generally similar among the SU herbicides in each compared pair. The final finding might suggest that the abundance of ALS2 is not as stable as that of ALS1. In addition, as a result of these new findings, together with expected further research, a suggested possibility is that substituting amino acids at Pro₁₉₇ generally could be estimated by plotting each accession's ED₉₀ values of imazosulfuron and bensulfuron‐methyl in a two‐dimensional graph.     

Development of a multiplex allele‐specific primer PCR assay for simultaneous detection of QoI and CAA fungicide resistance alleles in Plasmopara viticola populations

BACKGROUND: DNA‐based diagnosis has become a common tool for the evaluation of fungicide resistance in obligate phytopathogenic fungus Plasmopara viticola. RESULTS: A multiplex allele‐specific primer PCR assay has been developed for the rapid detection of fungicide resistance in P. viticola populations. With this assay, a glycine‐to‐alanine substitution at codon 143 of the P. viticola cytochrome b gene, which conferred QoI fungicide resistance, and a glycine‐to‐serine substitution at codon 1105 of the P. viticola cellulose synthase gene PvCesA3, which conferred CAA fungicide resistance, were detected simultaneously. CONCLUSION: It is suggested that the present assay is a reliable tool for the rapid and simultaneous detection of QoI and CAA fungicide resistance alleles in P. viticola populations. The assay required only 2 h from the sampling of symptoms to the detection of resistance alleles to both fungicides. Copyright © 2012 Society of Chemical Industry     

Embryo implantation is blocked by intraperitoneal injection with anti-LIF antibody in mice

Leukemia inhibitory factor (LIF) is essential for embryo implantation in mice and plays an important role in other mammals including humans. Intraperitoneal (i.p.) injections with anti-LIF antibody (7.5 μg/g body weight, 3 times) between D3 (D1 = day of vaginal plug detection) and D4 effectively blocked embryo implantation; complete inhibition was achieved in C57BL/6J mice, and implantation was dramatically reduced in ICR mice (reduced to 27%). Normal rabbit IgG used as the control did not disturb embryo implantation. Anti-LIF antibody was localized not only in the stroma, but also in the luminal epithelium and the glandular lumen after i.p. injections. Growth-arrested blastocysts were recovered from the uterus without any implantation sites in both strains. Blastocysts made contact with the LE on the antimesometrial side; however, uterine stromal cells did not undergo secondary decidual reaction, and the uterine lumen was open, even at D7. Several regions of decidualization in ICR mice treated with anti-LIF antibody were smaller than those of the control, and development of blastocysts was delayed. The expression of LIF-regulated genes, such as immune-responsive gene-1 and insulin-like growth factor binding protein-3, was significantly decreased in C57BL/6J mice treated with anti-LIF antibody compared with the control, but not in ICR mice. The present study demonstrated that simple ip injections of an antibody are sufficient to block one of the important factors involved in embryo implantation in mice, and this method should also be easily applicable to the investigation of other factors involved in implantation.     

A multiplex polymerase chain reaction for discriminating Erysipelothrix rhusiopathiae from Erysipelothrix tonsillarum.

Erysipelothrix rhusiopathiae is the causative agent of swine erysipelas, and it causes great economic losses in Japan and worldwide. In meat inspection, it is very important to distinguish E. rhusiopathiae from other bacteria showing similar clinical signs of disease or similar bacterial characteristics. To distinguish E. rhusiopathiae from Erysipelothrix tonsillarum, 2 polymerase chain reaction (PCR) systems were combined. The primer sets ERY-1F and ERY-2R were designed to amplify 2210 base pairs (bp) of nucleotide sequence specific for E. rhusiopathiae chromosomal DNA, and the primer sets MO101 and ERS-1R were designed to amplify 719 bp of nucleotide sequence including a highly conserved region of genus Erysipelothrix 16S rRNA. Two fragments were amplified when E. rhusiopathiae was used as the PCR template using the primer sets, whereas a single fragment was amplified when E. tonsillarum was used as the template. No fragments were amplified when nucleic acid from other bacteria that cause clinical signs similar to swine erysipelas were used as the template. Moreover, 5 specimens collected from postinspected swine carcasses were diagnosed as E. rhusiopathiae using the PCR described in this study, in agreement with results of microbiological tests for the genus Erysipelothrix, whereas negative samples were negative both in conventional bacterial tests and by PCR. The detection limit of multiplex PCR ranged from 10(2) to 10(4) colony forming units per reaction tube for positive samples. These results suggest that this method is useful for screening of swine erysipelas in meat inspection centers.     

Control of the collagen fibril diameter in the equine superficial digital flexor tendon in horses by decorin

The distribution pattern of collagen fibril diameter in the equine superficial digital flexor tendon (SDFT) is known to differ in central and peripheral areas of some regions. This study reports the essence of collagen fibril differences among different regions of the equine SDFT by transmission electron microscopic (TEM) and high-voltage electron microscopic observations and biochemical analysis. The distribution of large collagen fibrils increased but the density of collagen fibrils decreased from the proximal metacarpal region to the distal metacarpal region. Large collagen fibrils with an irregular cross-sectional profile were found more frequently in the middle metacarpal region than in other regions. Three-dimensional reconstruction of images of irregularly shaped collagen fibrils revealed that these fibrils are formed through fusion of small collagen fibrils with large ones. The amount of decorin, which reportedly inhibits the lateral fusion of collagen fibrils, decreased in the direction of the distal metacarpal region. On the other hand, the size of decorin gradually increased in the direction of the distal metacarpal region. These results suggest that regional differences in collagen fibril distribution and density of collagen fibrils in the SDFT are due, at least in part, to fusion of collagen fibrils and the concomitant regional differences in the amount and size of decorin.     

Focal fatty liver in a heifer: utility of ultrasonography in diagnosis

A 30-month-old Holstein heifer presented with a history of decreased appetite and respiratory signs. Sonographic examination of the liver incidentally revealed an area of increased echogenicity between the portal vein and the gallbladder. The lesion was nonspherical and had no mass effect or displacement of the adjacent vessels. Its boundaries, to the liver, were geographic. The liver specimen was histologically compatible with a diagnosis of focal fatty liver change (FFLC). The sonographic features of focal fatty infiltration of the liver are characteristic. Recognition of the ultrasonographic data is important to differentiate FFLC from other lesions.