Procedure for the efficient acquisition of progeny seeds from crossed potato plants grafted onto tomato

Potato, Solanum tuberosum L. is an important crop. However, it is difficult to breed potato cultivars by applying conventional crossing methods because potato has a tetraploid genome and is vegetatively propagated. Flower formation and tuber development occur simultaneously. Many potato cultivars hardly produce any fruits after crossing and fail to produce seeds. We report an improved procedure for obtaining progeny seeds by grafting potatoes onto tomatoes. The rate of fruit formation was more than 19% when the grafted potatoes were used for the crossing experiments, whereas crossing using the ungrafted plants showed a rate of 1.1%. This result suggests that our procedure results in the easy acquisition of null-segregant progenies by crossing mutant lines. It is also expected to improve conventional potato breeding.     

Identification of asymptomatic Entamoeba histolytica infection by a serological screening test: A cross-sectional study of an HIV-negative men who have sex with men cohort in Japan

BackgroundAmebiasis, caused by Entamoeba histolytica, is spreading in developing countries and in many developed countries as a sexually transmitted infection. Here, we evaluated the efficacy of serological screening to identify asymptomatic E. histolytica infection as a potential epidemiological control measure to limit its spread.Methodology/Principal findingsThis cross-sectional study was carried out between January and March 2021 in an HIV-negative men who have sex with men (MSM) cohort at the National Center for Global Health and Medicine. Serological screening was performed using a commercially available ELISA kit. For seropositive individuals, we performed stool polymerase chain reaction (PCR) to determine current E. histolytica infection. We performed E. histolytica serological screening of 312 participants. None had a history of E. histolytica infection prior to the study. The overall E. histolytica seropositivity was 6.7% (21/312), which was similar to that found by the rapid plasma reagin test (17/312). We identified current infection in 8 of 20 seropositive participants (40.0%) by stool PCR.Conclusions/SignificanceOur serological screening approach constitutes a potentially practical epidemiological strategy. Active epidemiological surveys, in combination with an effective screening strategy for asymptomatically infected individuals, should be applied to help reduce sexually transmitted E. histolytica infections.     

Cell surface modulation of CD26 by anti-1F7 monoclonal antibody. Analysis of surface expression and human T cell activation

In this paper, we examined in detail the ability of anti-1F7 to modulate 1F7 (CD26) surface expression as well as analyzed the functional relationship between the surface expression of CD3, CD2, and CD26 and human T cell activation. We showed that anti-1F7-induced modulation is an energy-dependent process that occurs via capping and internalization of the Ag-antibody complex. Although the recovery rate for Ag reexpression of 1F7 following optimal modulation is relatively delayed, reexpression of 1F7 is greatly accelerated following phorbol ester treatment. Most importantly, we demonstrated that modulation of the CD26 Ag leads to an enhancement in the proliferative activity of modulated human T cells treated with anti-CD3 or anti-CD2, which is preceded by an enhancement in Ca2+ mobilization. CD26 modulation also led to an increase in anti-CD3- or anti-CD2-mediated T cell clone proliferation. Finally, whereas modulation of the CD26 Ag has an effect on CD3- or CD2-induced T cell activation, modulation of the CD3/TCR complex inhibits the proliferative response of T cells incubated with anti-CD3 plus anti-1F7 or anti-CD2 plus anti-1F7. However, modulation of the CD2 structure does not affect anti-CD3- plus anti-1F7-induced human T cell activation. The above results thus provide additional evidence that the CD26 Ag plays an integral role in the regulation of human T cell activation.     

Fusion of bone marrow-derived cells with renal tubules contributes to renal dysfunction in diabetic nephropathy

Although diabetic nephropathy (DN) is a major cause of end-stage renal disease, the mechanism of dysfunction has not yet been clarified. We previously reported that in diabetes proinsulin-producing bone marrow-derived cells (BMDCs) fuse with hepatocytes and neurons. Fusion cells are polyploidy and produce tumor necrosis factor (TNF)-α, ultimately causing diabetic complications. In this study, we assessed whether the same mechanism is involved in DN. We performed bone marrow transplantation from male GFP-Tg mice to female C57BL/6J mice and produced diabetes by streptozotocin (STZ) or a high-fat diet. In diabetic kidneys, massive infiltration of BMDCs and tubulointerstitial injury were prominent. BMDCs and damaged tubular epithelial cells were positively stained with proinsulin and TNF-α. Cell fusion between BMDCs and renal tubules was confirmed by the presence of Y chromosome. Of tubular epithelial cells, 15.4% contain Y chromosomes in STZ-diabetic mice, 8.6% in HFD-diabetic mice, but only 1.5% in nondiabetic mice. Fusion cells primarily expressed TNF-α and caspase-3 in diabetic kidney. These in vivo findings were confirmed by in vitro coculture experiments between isolated renal tubular cells and BMDCs. It was concluded that cell fusion between BMDCs and renal tubular epithelial cells plays a crucial role in DN.     

Availability of Energy in Ester and Ether Derivatives of Glycols by Growing Chicks

Biological availability of 33 esters, 17 ethers and 2 acetals of ethanediol, 1,2-propanediol, 1,3-butanediol and 1,4-butanediol was compared by mini-test with chicks. Chicks can utilize esters of ethanediol, 1,2-propanediol and 1,3-butanediol with acetic acid and fatty acids of carbon chain length from 5 to 12 with more improved palatability than that of free acids, while availability of esters of these glycols with propionic and butyric acids was low. Esters of 1,4-butanediol and ether derivatives of these glycols was not available, except ethyl ether of di-ethanediol which was partially available. Acetacetal of ethanediol was partially available but n-butyracetal was not.     

Toll-like Receptors as a Target of Food-derived Anti-inflammatory Compounds

Toll-like receptors (TLRs) play a key role in linking pathogen recognition with the induction of innate immunity. They have been implicated in the pathogenesis of chronic inflammatory diseases, representing potential targets for prevention/treatment. Vegetable-rich diets are associated with the reduced risk of several inflammatory disorders. In the present study, based on an extensive screening of vegetable extracts for TLR-inhibiting activity in HEK293 cells co-expressing TLR with the NF-κB reporter gene, we found cabbage and onion extracts to be the richest sources of a TLR signaling inhibitor. To identify the active substances, we performed activity-guiding separation of the principal inhibitors and identified 3-methylsulfinylpropyl isothiocyanate (iberin) from the cabbage and quercetin and quercetin 4′-O-β-glucoside from the onion, among which iberin showed the most potent inhibitory effect. It was revealed that iberin specifically acted on the dimerization step of TLRs in the TLR signaling pathway. To gain insight into the inhibitory mechanism of TLR dimerization, we developed a novel probe combining an isothiocyanate-reactive group and an alkyne functionality for click chemistry and detected the probe bound to the TLRs in living cells, suggesting that iberin disrupts dimerization of the TLRs via covalent binding. Furthermore, we designed a variety of iberin analogues and found that the inhibition potency was influenced by the oxidation state of the sulfur. Modeling studies of the iberin analogues showed that the oxidation state of sulfur might influence the global shape of the isothiocyanates. These findings establish the TLR dimerization step as a target of food-derived anti-inflammatory compounds.     

Effects of acorn masting on population dynamics of three forest-dwelling rodent species in Hokkaido,Japan

The effects of the abundance of acorns of the oak, Quercus crispula, on the population dynamics of three rodent species (Apodemus speciosus, A. argenteus, and Clethrionomys rufocanus) were analyzed using time series data (1992–2006). The data were obtained in a forest in northern Hokkaido, Japan, by live trapping rodents and directly counting acorns on the ground. Apodemus speciosus generally increased in abundance following acorn masting. However, the clear effect of acorn abundance was not detected for the other two rodent species. Acorns of Q. crispula contain tannins, which potentially have detrimental effects on herbivores. Apodemus speciosus may reduce the damage caused by acorn tannins with tannin-binding salivary proteins and tannase-producing bacteria, whereas such physiological tolerance to tannins is not known in the other two rodent species. The differences in the effects of acorns between the three species may be due to differences in their physiological tolerance to tannins.     

Molecular bases for human complement C7 polymorphisms,C7*3 and C7*4

Complement C7 is one of the components of membrane attack complex (MAC) generated by the terminal complement cascade. C7 protein is polymorphic and most of its polymorphisms have been identified using isoelectric focusing (IEF), which detects protein charge differences. To date, the molecular bases of the polymorphisms detected by IEF have not been determined. In this paper, we describe the structural bases of two C7 IEF-detected polymorphisms, C7*3 and C7*4, both of which are common in Asian populations. C7*3 resulted from substitution of cysteine (Cys) at amino acid residue 106 by charged arginine (Arg; C106R), while charged lysine (Lys) at amino acid residue 398 was replaced by neutral glutamine (Gln; K398Q) in C7*4. As C7*3 is hypomorphic, it is important to study its possible associations with diseases such as immunological disorders and infections. We present genetic bases for this C7 polymorphism, which we determined using polymerase chain reaction (PCR)-based genotyping, a simple and accurate method suitable for large-scale studies.