Foxtail millet (Setaria italica) is an important grain crop that is grown in arid regions. Here we sequenced 916 diverse foxtail millet varieties, identified 2.58 million SNPs and used 0.8 million common SNPs to construct a haplotype map of the foxtail millet genome. We classified the foxtail millet varieties into two divergent groups that are strongly correlated with early and late flowering times. We phenotyped the 916 varieties under five different environments and identified 512 loci associated with 47 agronomic traits by genome-wide association studies. We performed a de novo assembly of deeply sequenced genomes of a Setaria viridis accession (the wild progenitor of S. italica) and an S. italica variety and identified complex interspecies and intraspecies variants. We also identified 36 selective sweeps that seem to have occurred during modern breeding. This study provides fundamental resources for genetics research and genetic improvement in foxtail millet.

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The purpose of this study was to noninvasively monitor tumor oxygenation and redox status during hyperoxygenation treatment, such as carbogen-breathing, in a murine tumor model using in vivo electron paramagnetic resonance (EPR) spectroscopy and imaging techniques. The study was performed using implanted lithium phthalocyanine (LiPc) microcrystals as the oximetry probe and 3-carbamoylproxyl ( Since tumor oxygenation is known to enhance the efficacy of radiotherapy, numerous experimental and clinical strategies have been introduced to improve it. A recent strategy combines breathing of carbogen gas (a mixture of 95% oxygen and 5% CO 2 ) with administration of nicotinamide (1). This combination is selected to specifically target the two major types of hypoxia thought to exist in tumors: 1) chronic hypoxia, which results from diffusion limitations of oxygen; and 2) acute hypoxia, which is caused by the intermittent constriction of tumor blood vessels. Carbogen is believed to increase the oxygen content of the blood while at the same time it promotes vasodilation based on its 5% CO 2 content. Nicotinamide is believed to reduce intermittent vessel closures (2). Using a combination of both carbogen and nicotinamide, studies have shown that oxygenation, and hence the sensitivity to radiotherapy, have been significantly enhanced in both single-dose (3) and fractionated regimens (4 -6). While these and most other studies have shown beneficial effects of carbogenbreathing on tumor oxygenation, it has also been shown in a few studies that carbogen-breathing produces variable oxygenation results (7,8). For example, in a recent report, Dewhirst et al. (8) reported that carbogen had no consistent effect on tumor blood flow and was ineffective at increasing pO 2 in R3230Ac tumors in rat. Their laser Doppler flow measurements showed that the tumor blood flow effects are not global but occur at the microregional level. Thus, irrespective of the tumor model, treatment modality, or outcome, a direct quantitative determination of tumor oxygenation will greatly aid in the evaluation of the tumor microenvironment.Methods used to measure oxygen concentration (termed "oximetry") or hypoxia in tumors have received considerable attention (9 -11). These methods include polarographic oxygen electrodes, comet assay, immunochemical techniques, optical spectroscopy, 19 F magnetic resonance spectroscopy (MRS) and imaging (MRI), 31 P-MRS, and electron paramagnetic resonance (EPR) spectroscopy and imaging. However, concerns regarding invasiveness, insufficient dynamic range of measurements, requirements for repetitive measurements, and poor spatial or temporal resolution have limited the realization of the full potential of these techniques. The polarographic oxygen electrode, often considered as the gold standard, is invasive, subject to pressure artifacts, and unsuitable for repeated measurements. Magnetic resonance techniques (MRI, blood oxygen level dependent (BOLD), Overhauser-enhanced MRI (OMRI), and EPR) and positron emission tomography (...

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