Plant oil is an important renewable resource for biodiesel production and for dietary consumption by humans and livestock. Through genetic mapping of the oil trait in plants, studies have reported multiple quantitative trait loci (QTLs) with small effects, but the molecular basis of oil QTLs remains largely unknown. Here we show that a high-oil QTL (qHO6) affecting maize seed oil and oleic-acid contents encodes an acyl-CoA:diacylglycerol acyltransferase (DGAT1-2), which catalyzes the final step of oil synthesis. We further show that a phenylalanine insertion in DGAT1-2 at position 469 (F469) is responsible for the increased oil and oleic-acid contents. The DGAT1-2 allele with F469 is ancestral, whereas the allele without F469 is a more recent mutant selected by domestication or breeding. Ectopic expression of the high-oil DGAT1-2 allele increases oil and oleic-acid contents by up to 41% and 107%, respectively. This work provides insights into the molecular basis of natural variation of oil and oleic-acid contents in plants and highlights DGAT as a promising target for increasing oil and oleic-acid contents in other crops.

a b s t r a c tThe improvement of the energy efficiency of belt conveyor systems can be achieved at equipment and operation levels. Specifically, variable speed control, an equipment level intervention, is recommended to improve operation efficiency of belt conveyors. However, the current implementations mostly focus on lower level control loops without operational considerations at the system level. This paper intends to take a model based optimization approach to improve the efficiency of belt conveyors at the operational level. An analytical energy model, originating from ISO 5048, is firstly proposed, which lumps all the parameters into four coefficients. Subsequently, both an off-line and an on-line parameter estimation schemes are applied to identify the new energy model, respectively. Simulation results are presented for the estimates of the four coefficients. Finally, optimization is done to achieve the best operation efficiency of belt conveyors under various constraints. Six optimization problems of a typical belt conveyor system are formulated, respectively, with solutions in simulation for a case study.

The phosphoprotein phosphatase 1 (PP1) catalytic subunit encoded by the Saccharomyces GLC7 gene is involved in control of glycogen metabolism, meiosis, translation, chromosome segregation, cell polarity, and G 2 /M cell cycle progression. It is also lethal when overproduced. We have isolated strains which are resistant to Glc7p overproduction lethality as a result of mutations in the SHP1 (suppressor of high-copy PP1) gene, which was previously encountered in a genomic sequencing project as an open reading frame whose interruption totally blocked sporulation and slightly slowed cell proliferation. These phenotypes also characterized our shp1 mutations, as did deficient glycogen accumulation. Lysates from the shp1 mutants were deficient in PP1 catalytic activity but exhibited no obvious abnormalities in the steady-state level or subcellular localization pattern of a catalytically active Glc7p-hemagglutinin fusion polypeptide. The lower level of PP1 activity in shp1 cells permitted substitution of a galactose-induced GAL10-GLC7 fusion for GLC7; depletion of Glc7p from these cells by growth in glucose medium resulted in G 2 /M arrest as previously observed for a glc7 cs allele but with depletion arrest occurring most frequently at a later stage of mitosis. The higher requirement of glycogen accumulation and sporulation for PP1 activity would permit their regulation via Glc7p activity, independent of its requirement for mitosis.During the last several years, studies employing fungal genetics have begun to make a major contribution to our understanding of the roles that serine/threonine phosphoprotein phosphatases (PPs) play in the control of vital processes in eukaryotic cells. The need for genetic analysis seems particularly acute for PP1 and PP2A, whose broad substrate and pathway specificities could hamper the resolution of regulatory questions by purely biochemical approaches (14, 44). The homolog of the mammalian PP1 catalytic subunit that is encoded by the GLC7 gene of Saccharomyces cerevisiae is essential for viability (17). At its restrictive temperature, a glc7 cs mutant ceases growth at G 2 /M (23), which is reminiscent of the Mphase growth arrest exhibited by PP1 conditional mutants of Aspergillus nidulans (15) and Schizosaccharomyces pombe (31,32). Other, nonlethal mutations in GLC7 implicate it in control of mitotic chromosome segregation (18), of glycogen metabolism (33), of meiosis and/or sporulation (11), of bud emergence (23), and of control of translation via dephosphorylation of eukaryotic initiation factor 2␣ (eIF-2␣) (55). Wild-type GLC7 is also lethal when overexpressed by fusion to a strong promoter (26) or by cloning on an inducible high-copy vector (see below). Lower levels of overexpression lead to decreased fidelity of chromosome segregation (18).In its effect on these disparate processes, it is still unclear whether Glc7p is actively regulatory, i.e., variably affecting the target process in response to an upstream effector or signal, or whether it is merely acting as a counterpoise to on...

No abstract

No abstract

No abstract

and reports receiving grants from Eli Lilly and Bristol-Myers Squibb. Zhang reports employment for Novartis. Tan reports employment for Novartis. Gasal reports employment for Novartis. Santarpia reports employment for Novartis. Dr. Johnson reports receiving grants from Cannon Medical Systems, grants and personal fees from Novartis, and personal fees from Hengrui Therapeutics, Daiichi Sankyo, Checkpoint Therapeutics, Lilly, and G1 Therapeutics; has a patent EGFR Mutation Testing with royalties. Hashemi declares no conflict of interest.

Purpose To develop and evaluate a super-resolution approach to reconstruct time-resolved four-dimensional magnetic resonance imaging (TR-4DMRI) with a high spatiotemporal resolution for multi-breathing cycle motion assessment. Methods and Materials A super-resolution approach was developed to combine fast 3D cine MRI with low-resolution during free breathing (FB) and high-resolution 3D static MRI during breath hold (BH) using deformable image registration (DIR). A T1-weighted, turbo field echo sequence, coronal 3D cine acquisition, partial Fourier approximation, and SENSE parallel acceleration were employed. The same MRI pulse sequence, field of view, and acceleration techniques were applied in both FB and BH acquisitions; the intensity-based Demons DIR method was used. Under an IRB-approved protocol, seven volunteers were studied with 3D cine FB scan (voxel size:5x5x5mm3) at 2Hz for 40s and a 3D static BH scan (2x2x2mm3). To examine the image fidelity of 3D cine and super-resolution TR-4DMRI, a mobile gel phantom with multi-internal targets was scanned at three velocities and compared with the 3D static image. Image similarity among 3D cine, 4DMRI, and 3D static was evaluated visually using difference image and quantitatively using voxel intensity correlation and Dice index (phantom only). Multi-breathing-cycle waveforms were extracted and compared in both phantom and volunteer images using the 3D cine as the references. Results Mild imaging artifacts were found in the 3D cine and TR-4DMRI of the mobile gel phantom with a Dice index of >0.95. Among seven volunteers, the super-resolution TR-4DMRI yielded high voxel-intensity correlation (0.92±0.05) and low voxel-intensity difference (<0.05). The detected motion differences between TR-4DMRI and 3D cine were −0.2±0.5mm (phantom) and −0.2±1.9mm (diaphragms). Conclusion Super-resolution TR-4DMRI has been reconstructed with adequate temporal (2Hz) and spatial (2x2x2mm3) resolutions. Further TR-4DMRI characterization and improvement are necessary before clinical applications. Multi-breathing cycles can be examined, providing patient-specific breathing irregularities and motion statistics for future 4D radiotherapy.