Improvement of the recessive genic male sterile lines with a subgenomic background in Brassica napus by molecular marker-assisted selection

Both the pollination control system and genetic distance are major factors in the utilization of crop heterosis. The recessive genic male sterile line (RGMS) 7-7365A (Bnms3ms3ms4ms4) has been widely applied to hybrid seed production because it can generate a completely male sterile population by crossing with the 7-7365C temporary line (Bnms3ms3rfrf). In this study, the sterile genes of 7-7365A were transferred to the new Brassica napus lines 7-749 and 7-750 with a high content of subgenomes by backcross breeding. We used the amplified fragment length polymorphism (AFLP) technique combined with bulk segregant analysis (BSA) to identify markers linked to the BnMs4 gene. Twelve AFLP markers linked to the BnMs4 gene were identified. Of them, SA06MG09 and P08MG16 were the closest makers, which were on either side of the gene at a distance of 0.9 and 0.8?cM, respectively. Twenty AFLP primer combinations were used to screen the F2, BC1F3, and BC2F4 populations from the breeding program, and the markers linked to the BnMs3 and BnMs4 genes were used to screen the BC2F4 populations. As a result, we obtained two types of improved sterile lines, 7-749A and 7-750A, and their indexes of subgenomic components (ISG) were 44.2?C49.8 and 20.2?C26.6%, respectively. The combining ability analyses of seed yield character were conducted in the crosses from the three sterile lines and ten restorers within a random block design in three environments for two successive years. The general combining ability (GCA) of the two improved sterile lines were significantly higher than the GCA of 7-7365A in every environment tested. The two improved sterile lines had stability in seed yield, and they will be used in the future for hybrid seed production.     

Lower median nerve block impairs precision grip.

The purpose of this study was to investigate precision grip impairment caused by a lower median nerve block at the wrist. The median nerve block was achieved by injecting bupivacaine hydrochloride into the carpal tunnel, which acutely simulated a median neuropathy. Seven healthy male subjects were instructed to grip, lift, and hold an instrumented handle within 60s using precision grip. The same tasks were performed before and after the nerve block. Force and torque data were recorded using two miniature 6-component force/torque transducers. The precision grip was quantified by the safety margin (i.e. the difference between the actual grip force and the minimal grip force to keep the object from dropping), the variation of grip force, and the migration area of center of pressure (i.e. the area defined by the center of pressure at a digit-transducer surface while holding the handle). Two subjects were unable to complete the precision grip tasks after the nerve block, and their data were excluded from the analyses. The median nerve block caused significant increases (P<0.05) in the safety margin of the grip force (>50%), the grip force variation (>80%), and the area of center of pressure migration (>250%). Median nerve block at the wrist impairs the fine motor control during precision grip. Our results corroborate the important role played by sensory function in hand fine motor control. Clinically, the measures related to precision grip have the potential to quantify impairment of hand function caused by neuromuscular disorders, to monitor the progress of a hand disorder, and to evaluate the efficacy of a treatment or rehabilitation procedure.     

Learning Environment,Preparedness and Satisfaction in Osteopathy in Europe: The PreSS Study

Objective

1) to assess the preparedness to practice and satisfaction in learning environment amongst new graduates from European osteopathic institutions; 2) to compare the results of preparedness to practice and satisfaction in learning environment between and within countries where osteopathy is regulated and where regulation is still to be achieved; 3) to identify possible correlations between learning environment and preparedness to practice.

Method

Osteopathic education providers of full-time education located in Europe were enrolled, and their final year students were contacted to complete a survey. Measures used were: Dundee Ready Educational Environment Measure (DREEM), the Association of American Medical Colleges (AAMC) and a demographic questionnaire. Scores were compared across institutions using one-way ANOVA and generalised linear model.

Results

Nine European osteopathic education institutions participated in the study (4 located in Italy, 2 in the UK, 1 in France, 1 in Belgium and 1 in the Netherlands) and 243 (77%) of their final-year students completed the survey. The DREEM total score mean was 121.4 (SEM: 1.66) whilst the AAMC was 17.58 (SEM:0.35). A generalised linear model found a significant association between not-regulated countries and total score as well as subscales DREEM scores (p<0.001). Learning environment and preparedness to practice were significantly positively correlated (r=0.76; p<0.01).

Discussion

A perceived higher level of preparedness and satisfaction was found amongst students from osteopathic institutions located in countries without regulation compared to those located in countries where osteopathy is regulated; however, all institutions obtained a ‘more positive than negative’ result. Moreover, in general, cohorts with fewer than 20 students scored significantly higher compared to larger student cohorts. Finally, an overall positive correlation between students’ preparedness and satisfaction were found across all institutions recruited.     

Interactions of uranyl ion with cytochrome <Emphasis Type="Italic">b</Emphasis><Subscript>5</Subscript> and its His39Ser variant as revealed by molecular simulation in combination with experimental methods

The biological toxicity of uranyl ion (UO₂²⁺) lies in interacting with proteins and disrupting their native functions. The structural and functional consequences of UO₂²⁺ interacting with cytochrome b ₅ (cyt b ₅), a small membrane heme protein, and its heme axial ligand His39Ser variant, cyt b ₅ H39S, were investigated both experimentally and theoretically. In experiments, although cyt b ₅ was only slightly affected, UO₂²⁺ binding to cyt b ₅ H39S with a K _D of 2.5 μM resulted in obvious alteration of the heme active site, and led to a decrease in peroxidase activity. Theoretically, molecular simulation proposed a uranyl ion binding site for cyt b ₅ at surface residues of Glu37 and Glu43, revealing both coordination and hydrogen bonding interactions. The information gained in this study provides insights into the mechanism of uranyl toxicity toward membrane protein at an atomic level.     

Impaired translation initiation activation and reduced protein synthesis in weaned piglets fed a low-protein diet

Weanling mammals (including infants) often experience intestinal dysfunction when fed a high-protein diet. Recent work with the piglet (an animal model for studying human infant nutrition) shows that reducing protein intake can improve gut function during weaning but compromises the provision of essential amino acids (EAA) for muscle growth. The present study was conducted with weaned pigs to test the hypothesis that supplementing deficient EAA (Lys, Met, Thr, Trp, Leu, Ile and Val) to a low-protein diet may maintain the activation of translation initiation factors and adequate protein synthesis in tissues. Pigs were weaned at 21 days of age and fed diets containing 20.7, 16.7 or 12.7% crude protein (CP), with the low-CP diets supplemented with EAA to achieve the levels in the high-CP diet. On Day 14 of the trial, tissue protein synthesis was determined using the phenylalanine flooding dose method. Reducing dietary CP levels decreased protein synthesis in pancreas, liver, kidney and longissimus muscle. A low-CP diet reduced the phosphorylation of eukaryotic initiation factor (eIF) 4E-binding protein-1 (4E-BP1) in skeletal muscle and liver while increasing the formation of an inactive eIF4E.4E-BP1 complex in muscle. Dietary protein deficiency also decreased the phosphorylation of mammalian target of rapamycin (mTOR) and the formation of an active eIF4E.eIF4G complex in liver. These results demonstrate for the first time that chronic feeding of a low-CP diet suppresses protein synthesis in animals partly by inhibiting mTOR signaling. Additionally, our findings indicate that supplementing deficient EAA to low-protein diets is not highly effective in restoring protein synthesis or whole-body growth in piglets. We suggest that conditionally essential amino acids (e.g., glutamine and arginine) may be required to maintain the activation of translation initiation factors and optimal protein synthesis in neonates.     

Astragaloside IV ameliorates peritoneal fibrosis by promoting PGC-1α to reduce apoptosis in vitro and in vivo

Prolonged exposure of the peritoneum to high glucose dialysate leads to the development of peritoneal fibrosis (PF), and apoptosis of peritoneal mesothelial cells (PMCs) is a major cause of PF. The aim of this study is to investigate whether Astragaloside IV could protect PMCs from apoptosis and alleviate PF. PMCs and rats PF models were induced by high glucose peritoneal fluid. We examined the pathology of rat peritoneal tissue by HE staining, the thickness of rat peritoneal tissue by Masson's staining, the number of mitochondria and oxidative stress levels in peritoneal tissue by JC-1 and DHE fluorescence staining, and mitochondria-related proteins and apoptosis-related proteins such as PGC-1α, NRF1, TFAM, Caspase3, Bcl2 smad2 were measured. We used hoechst staining and flow cytometry to assess the apoptotic rate of PMCs in the PF model, and further validated the observed changes in the expressions of PGC-1α, NRF1, TFAM, Caspase3, Bcl2 smad2 in PMCs. We further incubated PMCs with MG-132 (proteasome inhibitor) and Cyclohexylamine (protein synthesis inhibitor). The results demonstrated that Astragaloside IV increased the expression of PGC-1α by reducing the ubiquitination of PGC-1α. It was further found that the protective effects of Astragaloside IV on PMCs were blocked when PGC-1α was inhibited. In conclusion, Astragaloside IV effectively alleviated PF both in vitro and in vivo, possibly by promoting PGC-1α to enhance mitochondrial synthesis to reduce apoptotic effects.