Clustered QTL for source leaf size and yield traits in rice (Oryza sativa L.)

Improvement of plant type plays an important role in super-high yield breeding in rice (Oryza sativa L.). In the present study, a set of backcross recombinant inbred lines derived from a cross of 9311 and Zhenshan97, both elite indica hybrid parents, were developed to identify quantitative trait loci (QTL) for flag leaf size, panicle and yield traits. Forty-seven QTL for 14 traits were detected in common in the two environmental trials, of which nine genomic regions contained clustered QTL affecting plant type traits and yield traits. Four co-localized QTL on chromosomes 1, 6, 7 and 8 involving QTL for flag leaf size (flag leaf length, width and area) contained the QTL for yield traits such as panicle weight (PW) and secondary branch number (SBN), and in all cases alleles from 9311 increased source leaf size and were associated with increased sink size and yield (SBN and PW). Using a subset of overlapping substitution lines for the QTL region on chromosome 1, the QTL were validated and narrowed into a 990?kbp interval (RM3746?CRM10435) with pleiotropic effects on flag leaf size, PW, SBN and spikelet number per panicle. These QTL clusters with large effects on source leaf size and yield-related traits provide good targets for marker-assisted breeding for plant type improvement and high-yield potential in rice.     

Isolated angiitis of the central nervous system with tumor-like lesion, mimicking brain malignant glioma: a case report and review of the literature

Dermatofibrosarcoma protuberans is an uncommon locally aggressive malignant neoplasm that most frequently appears in the trunk, followed by the extremities, head, and neck. But occurrence in the breast is extremely rare. We present a case of a 28-year-old woman, who had a history of trauma 5 years previously and excision 1 year before presentation at our clinic. We performed wide excision, together with microscopic and immunohistochemical analysis. No postoperative oncologic treatment was used and she remains disease-free 1 year after the surgery without any tumor recurrence. Here, we report a case of dermatofibrosarcoma protuberans in the female breast and present a detailed discussion of the diagnosis and treatment with reference to available literatures.     

Studies of lysine cyclodeaminase from Streptomyces pristinaespiralis: Insights into the complex transition NAD+ state

Lysine cyclodeaminase (LCD) catalyzes the piperidine ring formation in macrolide-pipecolate natural products metabolic pathways from a lysine substrate through a combination of cyclization and deamination. This enzyme belongs to a unique enzyme class, which uses NAD⁺ as the catalytic prosthetic group instead of as the co-substrate. To understand the molecular details of NAD⁺ functions in lysine cyclodeaminase, we have determined four ternary crystal structure complexes of LCD-NAD⁺ with pipecolic acid (LCD-PA), lysine (LCD-LYS), and an intermediate (LCD-INT) as ligands at 2.26-, 2.00-, 2.17- and 1.80 Å resolutions, respectively. By combining computational studies, a NAD⁺-mediated “gate keeper” function involving NAD⁺/NADH and Arg49 that control the binding and entry of the ligand lysine was revealed, confirming the critical roles of NAD⁺ in the substrate access process. Further, in the gate opening form, a substrate delivery tunnel between ε-carboxyl moiety of Glu264 and the α-carboxyl moiety of Asp236 was observed through a comparison of four structure complexes. The LCD structure details including NAD⁺-mediated “gate keeper” and substrate tunnel may assist in the exploration the NAD⁺ function in this unique enzyme class, and in regulation of macrolide-pipecolate natural product synthesis.     

SRrp37, a novel splicing regulator located in the nuclear speckles and nucleoli,interacts with SC35 and modulates alternative pre‐mRNA splicing in vivo

We report here the identification and characterization of a novel SR‐related protein, referred to as SRrp37, based on its apparent molecular weight and subcellular location. SRrp37 was identified through a yeast two‐hybrid screen during the course of searching for proteins interacting with pNO40, a ribosomal 60S core subunit. SRrp37 exhibited two alternative spliced isoforms generated by differential usage of the translation start site with the longer one, SRrp37, initiating at first exon and the shorter, SRrp37‐2, starting from exon 2. Three distinct motifs can be discerned in the SRrp37 protein: (1) a serine–arginine (SR) dipeptide enriched domain, (2) a polyserine stretch, and (3) a potential nucleolar localization signal comprising a long array of basic amino acids. SRrp37's message was translated in tissue‐specific patterns with both isoforms expressed at comparable levels in tissues showing expression. Indirect immunofluorescence analysis with an anti‐SRrp37 antibody, as well as an experiment using myc‐tagged proteins, demonstrated that SRrp37 was localized in nucleoli and nuclear speckles. GST pull‐down assay showed that SRrp37 interacted physically with SC35. Using adenovirus E1A and chimeric calcitonin/dhfr constructs as splicing reporter minigenes, we found that SRrp37 modulated alternative 5′ and 3′ splicing in vivo. Together, SRrp37 may participate directly in splicing regulation or indirectly through interaction with SC35. Studies on this novel splicing regulator may provide new information on the intricate splicing machinery as related to the RNA metabolism involving processing of mRNA and rRNA. J. Cell. Biochem. 108: 304–314, 2009. © 2009 Wiley‐Liss, Inc.     

Simulations of Tubulin Sheet Polymers as Possible Structural Intermediates in Microtubule Assembly

The microtubule assembly process has been extensively studied, but the underlying molecular mechanism remains poorly understood. The structure of an artificially generated sheet polymer that alternates two types of lateral contacts and that directly converts into microtubules, has been proposed to correspond to the intermediate sheet structure observed during microtubule assembly. We have studied the self-assembly process of GMPCPP tubulins into sheet and microtubule structures using thermodynamic analysis and stochastic simulations. With the novel assumptions that tubulins can laterally interact in two different forms, and allosterically affect neighboring lateral interactions, we can explain existing experimental observations. At low temperature, the allosteric effect results in the observed sheet structure with alternating lateral interactions as the thermodynamically most stable form. At normal microtubule assembly temperature, our work indicates that a class of sheet structures resembling those observed at low temperature is transiently trapped as an intermediate during the assembly process. This work may shed light on the tubulin molecular interactions, and the role of sheet formation during microtubule assembly.     

Identification of the microbial diversity of wastewater nutrient removal processes using molecular biotechnology

The microbial communities of three sludge samples were identified by using a combined cloning-Denaturing Gradient Gel Electrophoresis (DGGE) method. Two communities were taken from the aerobic and the rotating biological contactor (RBC) of a novel hybrid system, named TNCU-I, which is a combined activated sludge-RBC bioprocess. The other sample was taken from the aerobic tank of a typical anaerobic-anoxic-aerobic (A2O) process. Acidovorax defluvii, Hydrogenophaga palleronii and Streptococcus suis were the most predominant bacteria, respectively, in TNCU-I activated sludge, TNCU-I RBC biofilm and A2O activated sludge, with abundances of 13.2%, 18.7% and 16.5%. Other predominant bacteria and their characteristics in wastewater treatment process are also described.     

Rapid Layer‐Specific Annealing Enabled by Ultraviolet LED with Estimation of Crystallization Energy for High‐Performance Perovskite Solar Cells

A rapid layer‐specific annealing on perovskite active layer enabled by ultraviolet (UV) light‐emitting diode (LED) is demonstrated and efficiency close to 19% is achieved in a simple planar inverted structure ITO/PEDOT:PSS/MAPbI₃/PC₇₁BM/Al without any device engineering. These results demonstrate that if the UV dosage is well managed, UV light is capable of annealing perovskite into high‐quality film rather than simply damaging it. Different in principle from other photonic treatment techniques that can heat up and damage underlying films, the UV‐LED‐annealing method enables layer‐specific annealing because LED light source is able to provide a specific UV wavelength for maximum light absorption of target film. Moreover, the layer‐specific photonic treatment allows accurate estimation of the crystallization energy required to form perovskite film at device quality level.