THE APPLICATION OF HISTONE ANALYSIS FOR IDENTIFYING DISTAL REGULATORY ELEMENTS - REGULATION OF FSHR

Mechanisms that regulate gene expression are fundamental to many complex biological processes and disease states. Genome-wide approaches that combine chromatin-immunoprecipitation (ChIP) and next-generation sequencing have greatly advanced our understanding of chromatin structure and the role that histone modification plays in transcriptional regulation. In particular, these advances revealed important associations between functional, non-coding DNAs and specific histone modifications, which have been used technically to identify numerous distal regulatory elements and furthered our knowledge of transcriptional regulation and cell-specific gene regulation. Fshr is a gene expressed only in testicular Sertoli cells and ovarian granulosa cells and its expression is critical for proper gonad function and fertility. Importantly, underlying its exquisite cell-specificity is a transcriptional mechanism limited to only two cell types, which previous studies revealed was dependent on distal regulatory elements. To help identify these elements, we used ChIP, combined with next-generation sequencing, to globally map Histone 3 Lysine 4 tri-methylation (H3K4me3) in Sertoli and myoid cells. H3K4me3 is a post-translational histone modification known to associate with distal regulatory elements and promoter regions of actively transcribed genes. Analysis of H3K4me3 enrichment profiles identified a distal site 3' to Fshr that was specific to Sertoli cells. Transient transfection analysis indicated the region represses Fshr promoter activity and in vitro binding analysis revealed that GATA-4 and an unknown protein bound to the region, implicating them in cell-specific regulation of Fshr. These studies provide evidence that Fshr is regulated by a distal regulatory element and have provided insight into the nature of these regulatory proteins. This work provides a database mapping H3K4me3 enrichment within Sertoli and peritubular myoid cells that can be used to identify new regulatory regions. Overall, these studies have furthered our knowledge of cell-specific gene regulation in Sertoli cells and provided new data that will lead to a better understanding of transcriptional regulation in Sertoli cells

Economics of payment cards: a status report

This article surveys the recent theoretical literature on payment cards (focusing on debit and credit cards) and studies this research's possible implications for the current public policy debate over payment card networks and the pricing of their services for both consumers and merchants.Payment systems ; Credit cards

Understanding the Role of Ligand Oxidation State: Design, Synthesis, and Reactivity of Electronically Asymmetric Molybdenum Dithiolene Complexes

Indiana University-Purdue University Indianapolis (IUPUI)Mononuclear molybdopterin enzymes are a large class of enzymes that are present in all phyla of life. All pterin containing enzymes posses a molybdopterin cofactor made up of a molybdenum metal center coordinated directly by a dithiolene ligand, which is appended to a pyranopterin cofactor. The majority of these enzymes catalyze oxygen atom transfer reactions that are concomitant with a transfer of two-electrons. We are hypothesizing that by altering the oxidation states of the dithiolene, the reactivity of the cofactor can be tuned for different substrates. This investigation focuses on the synthesis and characterization of oxo-MoIV(dithiolene) complexes that possess a fully reduced dithiolene ligand (dithiolene) and a fully oxidized dithiolene ligand (dithione). These complexes are designed to represent the asymmetry of the dithiolene ligand that is observed in the crystal structures of the DMSO reductase family. Asymmetric oxo-MoIV(dithiolene) complexes exhibit a unique structural property, a large fold angle along the S•••S vector of the dithione ligand. These complexes also show a positive solvatochromic effect in a range of polar to nonpolar solvents. The rich electrochemical properties of these redox active complexes and other characterization details such as IR, and NMR studies will be presented. Effects on the reactivity of these complexes using biologically relevant substrates will be discussed. The oxygen atom transfer reactivity has been probed by mass spectrometry and NMR spectroscopy. The presented complexes aide in highlighting the effect redox state of the dithiolene ligand has in modulating reactivit

Using Cover Crops to Control Weeds and Improve Soil Health

Herbicide-resistant weeds are challenging for producers to control in crop fields. This study explores the potential of cover crops to reduce weed pressure and improve soil health. Cover crops that had good canopy development, including grasses such as ryegrass and wheat, had the best weed control. Soybean yields were similar for all cover crops, though there was a trend towards lower yields for the brassica cover crops, Graza radish and forage collards. Soybeans grown after ryegrass had the highest yields

Using Cover Crops to Suppress Weeds and Improve Soil Health

Herbicide-resistant weeds are creating challenges for producers to control weeds in crop fields. This study explores the potential of cover crops to reduce weed pressure and im­prove soil health. Cover crops were planted after corn harvest in tilled and no-till fields, and included Graza radish, winter wheat, annual ryegrass, spring oats, winter oats, and forage collards. The control was fallow with herbicide application but no cover crop. Soil health was determined prior to cover crop termination. Graza radish and forage collards did not grow consistently in all plots due to poor germination and winter kill. Significant weed biomass was produced in the fallow plot or in plots with poor cover crop stands. Microbial biomass was much greater in the no-till field than in the tilled fields

Using Cover Crops as an Effective Weed Control Method in Southeast Kansas

Weed control is important to optimize crop production. This study was conducted to compare the effectiveness of different methods of fall-implemented weed control strategies. These strategies included different cover crop mixes, chemical control, and mechanical control. The cover crop mixes included four different commonly-planted winter cover crops. The chemical control was a fall-applied burndown, and the me­chanical control was vertical tillage. We found cover crop mixes that contained cereal rye provided the most weed control, with the chemical control being a close second. Spring oats die during the winter because of the low temperatures. The three cover crop mixes containing spring oats still provided 50% reduction in weed biomass the follow­ing spring. However, the fall tillage increased the amount of weed biomass

Effects of Spring-Planted Cover Crops on Weed Suppression and Winter Wheat Grain Yield in Western Kansas

Herbicide resistant (HR) weeds pose a major challenge to continuous no-tillage (NT) dryland crop management systems. Integrating cover crop (CCs) in dryland crop rota­tions could suppress weeds and provide a weed management option for HR weeds in NT systems. Field experiments were conducted to investigate weed suppression poten­tial of spring-planted CCs and their impacts on subsequent winter wheat grain yields. The CCs were oat/triticale, oat/triticale/pea, spring pea, and chem-fallow (standard) over 3 years and 2 locations in western Kansas. A weedy-fallow check was added to compare weed suppression of CCs in 2 out of the 3 years. Results showed CC mixtures of oat/triticale or oat/triticale/pea produced more biomass than spring pea by mid- June. Averaged across years, CC dry matter (DM) produced in Colby was 3560 lb/a with spring pea, 5850 lb/a for oat/triticale, and 5700 lb/a for the 3-way mixture of oat/triticale/pea. Similarly, DM production at HB Ranch (located 5 miles north of Brownell) was 2160 lb/a for spring pea, 4420 lb/a for oat/triticale or 4330 lb/a for oat/ triticale/pea. Regardless of study location, growing a CC resulted in \u3e 95% suppression of total weed biomass relative to the weedy-fallow check. Compared to chem-fallow, growing a CC reduced soil water content at winter wheat planting in 3 out of the 6 site-years (2017 at Colby, 2016 and 2017 at HB Ranch). At Colby, CCs reduced winter wheat grain yields in 2018 but not in 2016 or 2017. Except 2016, growing oat/triticale or oat/triticale/pea CC reduced wheat yields at HB Ranch. When averaged across the 3 years, wheat grain yields were 31 bu/a with chem-fallow, 30 bu/a after spring pea, and 34 bu/a with oat/triticale or oat/triticale/pea CC in Colby. Similarly, at HB Ranch, wheat grain yields averaged 50 bu/a with chem-fallow, 46 bu/a for spring pea, and 40 bu/a with either oat/triticale or oat/triticale/pea CCs

Common Sunflower Seedling Emergence across the U.S. Midwest

Predictions of weed emergence can be used by practitioners to schedule POST weed management operations. Common sunflower seed from Kansas was used at six Midwestern U.S. sites to examine the variability that 16 climates had on common sunflower emergence. Nonlinear mixed effects models, using a flexible sigmoidal Weibull function that included thermal time, hydrothermal time, and a modified hydrothermal time (with accumulation starting from January 1 of each year), were developed to describe the emergence data. An iterative method was used to select an optimal base temperature (Tb) and base and ceiling soil matric potentials (ψb and ψc) that resulted in a best-fit regional model. The most parsimonious model, based on Akaike\u27s information criterion (AIC), resulted when Tb = 4.4 C, and ψb = −20000 kPa. Deviations among model fits for individual site years indicated a negative relationship (r = −0.75; P \u3c 0.001) between the duration of seedling emergence and growing degree days (Tb = 10 C) from October (fall planting) to March. Thus, seeds exposed to warmer conditions from fall burial to spring emergence had longer emergence periods