An Integrated High-density Linkage Map of Soybean with RFLP, SSR, STS, and AFLP Markers Using A Single F2 Population

Soybean [Glycine max (L.) Merrill] is the most important leguminouscrop in the world due to its high contents of high-quality proteinand oil for human and animal consumption as well as for industrialuses. An accurate and saturated genetic linkage map of soybeanis an essential tool for studies on modern soybean genomics.In order to update the linkage map of a F₂ population derivedfrom a cross between Misuzudaizu and Moshidou Gong 503 and tomake it more informative and useful to the soybean genome researchcommunity, a total of 318 AFLP, 121 SSR, 108 RFLP, and 126 STSmarkers were newly developed and integrated into the frameworkof the previously described linkage map. The updated geneticmap is composed of 509 RFLP, 318 SSR, 318 AFLP, 97 AFLP-derivedSTS, 29 BAC-end or EST-derived STS, 1 RAPD, and five morphologicalmarkers, covering a map distance of 3080 cM (Kosambi function)in 20 linkage groups (LGs). To our knowledge, this is presentlythe densest linkage map developed from a single F₂ populationin soybean. The average intermarker distance was reduced to2.41 from 5.78 cM in the earlier version of the linkage map.Most SSR and RFLP markers were relatively evenly distributedamong different LGs in contrast to the moderately clusteredAFLP markers. The number of gaps of more than 25 cM was reducedto 6 from 19 in the earlier version of the linkage map. Thecoverage of the linkage map was extended since 17 markers weremapped beyond the distal ends of the previous linkage map. Inparticular, 17 markers were tagged in a 5.7 cM interval betweenCE47M5a and Satt100 on LG C2, where several important QTLs wereclustered. This newly updated soybean linkage map will enableto streamline positional cloning of agronomically importanttrait locus genes, and promote the development of physical maps,genome sequencing, and other genomic research activities.     

Menaquinone biosynthesis potentiates haem toxicity in Staphylococcus aureus

Staphylococcus aureus is a pathogen that infects multiple anatomical sites leading to a diverse array of diseases. Although vertebrates can restrict the growth of invading pathogens by sequestering iron within haem, S. aureus surmounts this challenge by employing high‐affinity haem uptake systems. However, the presence of excess haem is highly toxic, necessitating tight regulation of haem levels. To overcome haem stress, S. aureus expresses the detoxification system HrtAB. In this work, a transposon screen was performed in the background of a haem‐susceptible, HrtAB‐deficient S. aureus strain to identify the substrate transported by this putative pump and the source of haem toxicity. While a recent report indicates that HrtAB exports haem itself, the haem‐resistant mutants uncovered by the transposon selection enabled us to elucidate the cellular factors contributing to haem toxicity. All mutants identified in this screen inactivated the menaquinone (MK) biosynthesis pathway. Deletion of the final steps of this pathway revealed that quinone molecules localizing to the cell membrane potentiate haem‐associated superoxide production and subsequent oxidative damage. These data suggest a model in which membrane‐associated haem and quinone molecules form a redox cycle that continuously generates semiquinones and reduced haem, both of which react with atmospheric oxygen to produce superoxide.     

Lipid Peroxidation and Antioxidant System in the Tumor and in the Blood of Patients with Nasopharyngeal Carcinoma

Reactive oxygen species play a key role in cancer development by inducing and maintaining the oncogenic phenotypes of cancer cells. In this study, we examined lipid peroxidation and antioxidant enzymes activities in the blood and in the tumor of nasopharyngeal carcinoma patients. Plasma malondialdehyde, conjugated dienes, erythrocytes catalase, and superoxide dismutase activities have been measured in 30 untreated nasopharyngeal carcinoma patients and 30 controls on one hand. On the other hand, tumor malondialdehyde level, catalase, and superoxide dismutase activities have been measured in five nasopharyngeal carcinoma patients and compared with four controls. The lipid peroxidation was confirmed in the plasma by the high levels of malondialdehyde and conjugated dienes (p?<?0.001, respectively). Additionally, significantly higher concentrations of malondialdehyde were found in biopsies compared to the control group (p?<?0.001). In erythrocytes, superoxide dismutase activity was higher in patients than in controls (p?<?0.05), while it was unchanged in the tumor (p?>?0.05). Both erythrocytes and tumor catalase activities were significantly lower in patients than in controls (p?<?0.001, respectively). Statistical studies have shown a positive correlation between malondialdehyde level and IgA antibodies level against Epstein–Barr virus capsid antigen (p?<?0.05). In conclusion, we reported the presence of an oxidative stress in the blood and in the biopsies of nasopharyngeal carcinoma patients where Epstein–Barr virus seems to play a role.     

Whole inedible date in the grower-finisher broiler diets and the impact on productive performance, nutrient digestibility and meat quality

The growth performance, carcass characteristics and meat quality measurements were evaluated on broiler chicks fed different dietary levels of whole inedible dates (WID). WID used in this study were consisted of date fruits (～850 g/kg) and date pits (～150 g/kg). Three hundred unsexed Lohman broiler chicks were randomly and equally distributed into six groups. Each was formed of 50 chicks (five replicates, 10 chicks per replicate), and was assigned to a dietary treatment. Six dietary treatments of WID (0, 30, 60, 90, 120 and 150 g/kg feed) were included in the formation of isocaloric (metabolizable energy of ～3060 kcal/kg feed) and isonitrogenous (CP of ～192 g/kg feed) broiler rations. The treated rations were fed to the group chicks between 15 and 42 days of age (the experimental period). A straight-run design was considered. At 42 days of age, five males from each treatment were randomly chosen and slaughtered to determine carcass characteristics, internal organs and meat quality measurements. Digestibility of nutrients was measured at the end of the experimental period using five caged-individual males per treatment. The inclusion of broiler rations on WID for up to 150 g/kg feed, over the experimental period, did not significantly influence body weight gain (1452 to 1521 g/chick), feed intake (3268 to 3621 g/chick), feed conversion ratio (2.26 to 2.36 kg/kg) and dressed carcass (63.4% to 67.3%). In addition, levels of WID for up to 150 g/kg feed did not significantly influence the digestibility of nutrients and meat quality measurements. Such results suggest the possible inclusion of broiler rations on WID for up to 150 g/kg feed, during the period of 15 to 42 days of age without adverse effects on growth performance and meat quality.     

Circadian rhythms in toxic effects of the serotonin antagonist ondansetron in mice

The aim of the study was to learn whether the lethal and the motor incoordination (ataxia) side effect of ondansetron (Zophren) administration is dosing-time dependent. Ondansetron is a serotonin 5-HT3 receptor antagonist used primarily to control nausea and vomiting arising from cytotoxic chemo- and radiotherapy. A total of 210 male Swiss mice 10 to 12 weeks of age were synchronized for 3 weeks by 12 h light (rest span)/12 h dark (activity span). Different doses of ondansetron were injected intraperitoneally (i.p.) at fixed times during the day to determine both the sublethal (TD50) and lethal (LD50) doses, which were, respectively, 3.7 +/- 0.6 mg/kg and 4.6 +/- 0.5 mg/kg. In the chronotoxicologic study a single dose of ondansetron (3.5 mg/kg, i.p.) was administered to different and comparable groups of animals at four different circadian stages [1, 7, 13, and 19 h after light onset (HALO)]. The lethal toxicity was statistically significantly dosing time-dependent (chi2 = 21.51, p < 0.0001). Drug dosing at 1 HALO resulted in 100% survival rate whereas drug dosing at 19 HALO was only one-half that (52%). Similarly, lowest and highest ataxia occurred when ondansetron was injected at 1 and 19 HALO, respectively (chi2 = 22.24, p < 0.0001). Effects on rectal temperature were also dosing-time related (Cosinor analysis, p < 0.0001). The characteristics of the waveform describing the temporal patterns differed between the studied variables, e.g., lethal toxicity and survival rate showing two peaks and rectal temperature showing one peak in the 24 h time series waveform pattern. Cosinor analysis also revealed a statistically significant ultradian (tau = 8 h) rhythmic component in the considered variables. Differences in curve patterns in toxicity elicited by ondansetron on a per end point basis are hypothesized to represent the phase relations between the identified 24 h and 8 h periodicities.     

Comparative evaluation of D-glucosyl thiouronium, glucosylthio heterocycles, Daonil, and insulin as inhibitors for hepatic glycosidases

Comparison of the in vivo and in vitro effects of S-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)thiuronium bromide (1), 2-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylthio-1,3,4-thiadiazolin-5-thione (2), and 2-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosylthio)-1,3-benzoxazole (3), as well as the antidiabetics Daonil and insulin on glycosidase enzymes has been investigated. Compound 1 inhibited both alpha- and beta-glucosidases, but the inhibition was more potent with the beta-enzyme. Compound 2 was found to be a weaker inhibitor of these enzymes, while compound 3 showed a slight apparent activation.     

A convenient method for the synthesis of 2-(beta-D-glycopyranosylthio) pyridines

Treatment of piperidinium salts of dihydropyridinethiolates 3 with glycosyl bromides 4 in dry acetone provides a convenient and high yielding synthesis of 1,4-dihydro-3-cyanopyridine thioglycosides 5. The structures of 5 were confirmed by oxidation as well as by 1H NMR and 13C NMR spectral analysis.     

Cloning and Characterization of OsORC2, A New Member of Rice Origin Recognition Complex

In eukaryotic cells, the origin recognition complex (ORC) governs the initiation site of DNA replication and formation of the prereplication complex. The isolation, characterization and tissue-specific expression of a putative ORC subunit 2 (OsORC2) in Oryza sativa is described here. A novel cDNA fragment encoding rice ORC2 was isolated by screening the subtractive library, which had a higher expression level in inflorescence meristem than in shoot apical meristem. The full-length cDNA of rice ORC2 was obtained by the method of rapid amplification of cDNA ends, which contained an 1140 bp open reading frame encoding a 379 amino acid polypeptide. Sequence alignment shows that there is a high homology between the deduced amino sequence of OsORC2 and maize ORC2 (85%). The tissue-specific expression pattern of OsORC2 reveals that it is abundant in roots, seedling and inflorescence meristem, while its expression level is much lower in mature leaves and shoot.