Star Formation in Massive Protoclusters in the Monoceros OB1 Dark Cloud

We present far-infrared, submillimetre, and millimetre observations of bright IRAS sources and outflows that are associated with massive CS clumps in the Monoceros OB1 Dark Cloud. Individual star-forming cores are identified within each clump. We show that combining submillimetre maps, obtained with SCUBA on the JCMT, with HIRES-processed and modelled IRAS data is a powerful technique that can be used to place better limits on individual source contributions to the far-infrared flux in clustered regions. Three previously categorized "Class I objects" are shown to consist of multiple sources in different evolutionary stages. In each case, the IRAS point source dominates the flux at 12 and 25 microns. In two cases, the IRAS point source is not evident at submillimetre wavelengths. The submillimetre sources contribute significantly to the 60 and 100 micron fluxes, dominating the flux in the 100 micron waveband. Using fluxes derived from our technique, we present the spectral energy distribution and physical parameters for an intermediate-mass Class 0 object in one of the regions. Our new CO J=2-1 outflow maps of the three regions studied indicate complex morphology suggestive of multiple driving sources. We discuss the possible implications of our results for published correlations between outflow momentum deposition rates and "source" luminosities, and for using these derived properties to estimate the ratio of mass ejection rates to mass accretion rates onto protostars.Comment: 12 pages, 11 gzipped gif figures, LaTex file and MNRAS style files, accepted by MNRAS, v2: reference typos and author affiliation have been correcte

Identification and characterization of secreted and pathogenesis-related proteins in Ustilago maydis

Interactions between plants and fungal pathogens require a complex interplay at the plant–fungus interface. Extracellular effector proteins are thought to play a crucial role in establishing a successful infection. To identify pathogenesis-related proteins in Ustilago maydis we combined the isolation of secreted proteins using a signal sequence trap approach with bioinformatic analyses and the subsequent characterization of knock-out mutants. We identified 29 secreted proteins including hydrophobins and proteins with a repetitive structure similar to the repellent protein Rep1. Hum3, a protein containing both, a hydrophobin domain and a repetitive Rep1-like region, is shown to be processed during passage through the secretory pathway. While single knock-outs of hydrophobin or repellent-like genes did not affect pathogenicity, we found a strong effect of a double knock-out of hum3 and the repetitive rsp1. Yeast-like growth, mating, aerial hyphae formation and surface hydrophobicity were unaffected in this double mutant. However, pathogenic development in planta stops early after penetration leading to a complete loss of pathogenicity. This indicates that Hum3 and Rsp1 are pathogenicity proteins that share an essential function in early stages of the infection. Our results demonstrate that focusing on secreted proteins is a promising way to discover novel pathogenicity proteins that might be broadly applied to a variety of fungal pathogens

Russia’s Legal Transitions: Marxist Theory, Neoclassical Economics and the Rule of Law

We review the role of economic theory in shaping the process of legal change in Russia during the two transitions it experienced during the course of the twentieth century: the transition to a socialist economy organised along the lines of state ownership of the means of production in the 1920s, and the transition to a market economy which occurred after the fall of the Soviet Union in the 1990s. Despite differences in methodology and in policy implications, Marxist theory, dominant in the 1920s, and neoclassical economics, dominant in the 1990s, offered a similarly reductive account of law as subservient to wider economic forces. In both cases, the subordinate place accorded to law undermined the transition process. Although path dependence and history are frequently invoked to explain the limited development of the rule of law in Russia during the 1990s, policy choices driven by a deterministic conception of law and economics also played a role.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s40803-015-0012-

Arabidopsis R2R3-MYB transcription factor AtMYB60 functions as a transcriptional repressor of anthocyanin biosynthesis in lettuce (Lactuca sativa)

The MYB transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. We evaluated the possible roles of the Arabidopsis R2R3-MYB transcription factors in flavonoid biosynthesis because they are induced by UV-B irradiation but their associated phenotypes are largely unexplored. We isolated their genes by RACE-PCR, and performed transgenic approach and metabolite analyses in lettuce (Lactuca sativa). We found that one member of this protein family, AtMYB60, inhibits anthocyanin biosynthesis in the lettuce plant. Wild-type lettuce normally accumulates anthocyanin, predominantly cyanidin and traces of delphinidin, and develops a red pigmentation. However, the production and accumulation of anthocyanin pigments in AtMYB60-overexpressing lettuce was inhibited. Using RT-PCR analysis, we also identified the complete absence or reduction of dihydroflavonol 4-reductase (DFR) transcripts in AtMYB60- overexpressing lettuce (AtMYB60-117 and AtMYB60-112 lines). The correlation between the overexpression of AtMYB60 and the inhibition of anthocyanin accumulation suggests that the transcription factorAtMYB60 controls anthocyanin biosynthesis in the lettuce leaf. Clarification of the roles of the AtMYB60 transcription factor will facilitate further studies and provide genetic tools to better understand the regulation in plants of the genes controlled by the MYB-type transcription factors. Furthermore, the characterization of AtMYB60 has implications for the development of new varieties of lettuce and other commercially important plants with metabolic engineering approaches

Loss of Mitogen-Activated Protein Kinase Kinase Kinase 4 (MAP3K4) Reveals a Requirement for MAPK Signalling in Mouse Sex Determination

The boygirl (byg) mouse mutant reveals that MAP3K4-mediated signaling is necessary for normal SRY expression and testis specification in the developing mouse gonad

The Mating Type Locus (MAT) and Sexual Reproduction of Cryptococcus heveanensis: Insights into the Evolution of Sex and Sex-Determining Chromosomal Regions in Fungi

Mating in basidiomycetous fungi is often controlled by two unlinked, multiallelic loci encoding homeodomain transcription factors or pheromones/pheromone receptors. In contrast to this tetrapolar organization, Cryptococcus neoformans/Cryptococcus gattii have a bipolar mating system, and a single biallelic locus governs sexual reproduction. The C. neoformans MAT locus is unusually large (>100 kb), contains >20 genes, and enhances virulence. Previous comparative genomic studies provided insights into how this unusual MAT locus might have evolved involving gene acquisitions into two unlinked loci and fusion into one contiguous locus, converting an ancestral tetrapolar system to a bipolar one. Here we tested this model by studying Cryptococcus heveanensis, a sister species to the pathogenic Cryptococcus species complex. An extant sexual cycle was discovered; co-incubating fertile isolates results in the teleomorph (Kwoniella heveanensis) with dikaryotic hyphae, clamp connections, septate basidia, and basidiospores. To characterize the C. heveanensis MAT locus, a fosmid library was screened with C. neoformans/C. gattii MAT genes. Positive fosmids were sequenced and assembled to generate two large probably unlinked MAT gene clusters: one corresponding to the homeodomain locus and the other to the pheromone/receptor locus. Strikingly, two divergent homeodomain genes (SXI1, SXI2) are present, similar to the bE/bW Ustilago maydis paradigm, suggesting one or the other homeodomain gene was recently lost in C. neoformans/C. gattii. Sequencing MAT genes from other C. heveanensis isolates revealed a multiallelic homeodomain locus and at least a biallelic pheromone/receptor locus, similar to known tetrapolar species. Taken together, these studies reveal an extant C. heveanensis sexual cycle, define the structure of its MAT locus consistent with tetrapolar mating, and support the proposed evolutionary model for the bipolar Cryptococcus MAT locus revealing transitions in sexuality concomitant with emergence of a pathogenic clade. These studies provide insight into convergent processes that independently punctuated evolution of sex-determining loci and sex chromosomes in fungi, plants, and animals