The Chironomid Species Collected with Light Traps at the Side of Shibayamagata Lake, Ishikawa Prefecture

Collection of adult midges of the family Chironomidae with a light trap were carried out by Sumita on the shore of Lake Shibayamagata, Ishikawa Prefecture, 4 times in 1998, on June 9, July 15, August 11 and September 10. The specimens were preserved in 70% ethanol, sent to Suzuki for screening of species and mounting a part of them on slides in gum-chloral medium, and were sent to Sasa for species identification. A total of 62 adult male specimens among them were examined, and were classified into 24 species belonging to 15 genera, among which 6 are described here as new species. Several among them are rare or poorly known species, and are additionally described. At least two species, Tanytarsus oyamai and Polypedilum kyotoense, which were confirmed as important allergens causing bronchial asthma, were also included in the collections

Unstable Chromosome Aberrations Do Not Accumulate in Normal Human Fibroblast after Fractionated X-Irradiation

We determined the frequencies of dicentric chromosomes per cell in non-dividing confluent normal human fibroblasts (MRC-5) irradiated with a single 1 Gy dose or a fractionated 1 Gy dose (10X0.1 Gy, 5X0.2 Gy, and 2X0.5 Gy). The interval between fractions was between 1 min to 1440 min. After the completion of X-irradiation, the cells were incubated for 24 hours before re-plating at a low density. Then, demecolcine was administrated at 6 hours, and the first mitotic cells were collected for 42 hours. Our study demonstrated that frequencies of dicentric chromosomes in cells irradiated with a 1 Gy dose at different fractions were significantly reduced if the fraction interval was increased from 1 min to 5 min (p<0.05, χ2- test). Further increasing the fraction interval from 5 up to 1440 min did not significantly affect the frequency of dicentric chromosomes. Since misrejoining of two independent chromosome breaks introduced in close proximity gives rise to dicentric chromosome, our results indicated that such circumstances might be quite infrequent in cells exposed to fractionated X-irradiation with prolonged fraction intervals. Our findings should contribute to improve current estimation of cancer risk from chronic low-dose-rate exposure, or intermittent exposure of low-dose radiation by medical exposure

Interplay of a non-conjugative integrative element and a conjugative plasmid in the spread of antibiotic resistance via suicidal plasmid transfer from an aquaculture Vibrio isolate

The capture of antimicrobial resistance genes (ARGs) by mobile genetic elements (MGEs) plays a critical role in resistance acquisition for human-associated bacteria. Although aquaculture environments are recognized as important reservoirs of ARGs, intra- and intercellular mobility of MGEs discovered in marine organisms is poorly characterized. Here, we show a new pattern of interspecies ARGs transfer involving a ‘non-conjugative’ integrative element. To identify active MGEs in a Vibrio ponticus isolate, we conducted whole-genome sequencing of a transconjugant obtained by mating between Escherichia coli and Vibrio ponticus. This revealed integration of a plasmid (designated pSEA1) into the chromosome, consisting of a self-transmissible plasmid backbone of the MOBH group, ARGs, and a 13.8-kb integrative element Tn6283. Molecular genetics analysis suggested a two-step gene transfer model. First, Tn6283 integrates into the recipient chromosome during suicidal plasmid transfer, followed by homologous recombination between the Tn6283 copy in the chromosome and that in the newly transferred pSEA1. Tn6283 is unusual among integrative elements in that it apparently does not encode transfer function and its excision barely generates unoccupied donor sites. Thus, its movement is analogous to the transposition of insertion sequences rather than to that of canonical integrative and conjugative elements. Overall, this study reveals the presence of a previously unrecognized type of MGE in a marine organism, highlighting diversity in the mode of interspecies gene transfer

Anti-glycopeptide mAb LpMab-21 against Podoplanin

Human podoplanin (hPDPN), which binds to C‐type lectin‐like receptor‐2 (CLEC‐2), is involved in platelet aggregation and cancer metastasis. The expression of hPDPN in cancer cells or cancer‐associated fibroblasts indicates poor prognosis. Human lymphatic endothelial cells, lung‐type I alveolar cells, and renal glomerular epithelial cells express hPDPN. Although numerous monoclonal antibodies (mA bs) against hPDPN are available, they recognize peptide epitopes of hPDPN. Here, we generated a novel anti‐hPDPN mA b, LpMab‐21. To characterize the hPDPN epitope recognized by the LpMab‐21, we established glycan‐deficient CHO‐S and HEK‐293T cell lines, using the CRISPR/Cas9 or TALEN. Flow cytometric analysis revealed that the minimum hPDPN epitope, in which sialic acid is linked to Thr76, recognized by LpMab‐21 is Thr76–Arg79. LpMab‐21 detected hPDPN expression in glioblastoma, oral squamous carcinoma, and seminoma cells as well as in normal lymphatic endothelial cells. However, LpMab‐21 did not react with renal glomerular epithelial cells or lung type I alveolar cells, indicating that sialylation of hPDPN Thr76 is cell‐type‐specific. LpMab‐21 combined with other anti‐hPDPN antibodies that recognize different epitopes may therefore be useful for determining the physiological function of sialylated hPDPN

Interplay of a non-conjugative integrative element and a conjugative plasmid in the spread of antibiotic resistance via suicidal plasmid transfer from an aquaculture Vibrio isolate

<div><p>The capture of antimicrobial resistance genes (ARGs) by mobile genetic elements (MGEs) plays a critical role in resistance acquisition for human-associated bacteria. Although aquaculture environments are recognized as important reservoirs of ARGs, intra- and intercellular mobility of MGEs discovered in marine organisms is poorly characterized. Here, we show a new pattern of interspecies ARGs transfer involving a ‘non-conjugative’ integrative element. To identify active MGEs in a <i>Vibrio ponticus</i> isolate, we conducted whole-genome sequencing of a transconjugant obtained by mating between <i>Escherichia coli</i> and <i>Vibrio ponticus</i>. This revealed integration of a plasmid (designated pSEA1) into the chromosome, consisting of a self-transmissible plasmid backbone of the MOB_H group, ARGs, and a 13.8-kb integrative element Tn<i>6283</i>. Molecular genetics analysis suggested a two-step gene transfer model. First, Tn<i>6283</i> integrates into the recipient chromosome during suicidal plasmid transfer, followed by homologous recombination between the Tn<i>6283</i> copy in the chromosome and that in the newly transferred pSEA1. Tn<i>6283</i> is unusual among integrative elements in that it apparently does not encode transfer function and its excision barely generates unoccupied donor sites. Thus, its movement is analogous to the transposition of insertion sequences rather than to that of canonical integrative and conjugative elements. Overall, this study reveals the presence of a previously unrecognized type of MGE in a marine organism, highlighting diversity in the mode of interspecies gene transfer.</p></div