The self-incompatibility phenotype in brassica is altered by the transformation of a mutant S locus receptor kinase

The self-incompatible (SI) Brassica napus line W1, which carries the 910 S allele, was transformed with an inactive copy of the 910 S locus receptor kinase (SRK) gene. Two transformed lines were analyzed based on their heritable ability to set self-seed. The first line was virtually completely self-compatible (SC), and reciprocal pollinations with the original W1 line demonstrated that only the stigma side of the SI phenotype was altered. An analysis of the expression of endogenous SRK-910 demonstrated that the mechanism of transgene action is via gene suppression. Furthermore, the expression of the S locus glycoprotein gene present in the 910 allele (SLG-910), SLG-A10, which is derived from a nonfunctional S allele, and an S locus-related gene were also suppressed. When the transgene was crossed into another SI line carrying the A14 S allele, it was also capable of suppressing the expression of the endogenous genes and of making this line SC. The second transgenic line studied was only partly SC. In this case as well, only the stigma phenotype was affected, although no gene suppression was detected for endogenous SRK-910 or SLG-910. In this line, the expression of the transgene most likely was causing the change in phenotype, and no effect was observed when this transgene was crossed into the other SI line. Therefore, this work reinforces the hypothesis that the SRK gene is required, but only for the stigma side of the SI phenotype, and that a single transgene can alter the SI phenotype of more than one S allele.     

“On A Piece of Chalk”-Updated1

ABSTRACT. Many advances have been made in our knowledge of the biology of foraminifera over the past several decades. Fine structural, biophysical, and molecular biological studies have shown that the most prominent components of their distinctive bidirectional granuloreliculopods are bundles of micro tubules linked by crossbridges to each other, as well as to membrane-bound organelles and the plasma membrane. the microtubules ratchet past each other as dynein transduces the free energy of ATP to produce pseudopodal movements. In spite of the fact that there are over 40,000 described species of living and fossil species of foraminifera, there have been many recent exciting discoveries of new species and groups. New casting techniques are providing us with greater understanding of the complexities and functional aspects of form in the group. Significant advances are being made in understanding the distribution and energetics of deep-sea forms. Larger and planktonic foraminifera are the hosts for a particularly diverse range of endosymbiotic algae, including dinoflagellates, chlorophytes, unicellular rhodophytes, and diatoms. Chloroplast husbandry also occurs. Significant research effort has been expended yielding us considerable insight into various aspects of the endosymbiotic phenomenon. A unified conceptual framework has been drawn to help us understand the life cycle options found in foraminifera.     

Diets high in selenium and isoflavones decrease androgen-regulated gene expression in healthy rat dorsolateral prostate

Background  

High dietary intake of selenium or soybean isoflavones reduces prostate cancer risk. These components each affect androgen-regulated gene expression. The objective of this work was to determine the combined effects of selenium and isoflavones on androgen-regulated gene expression in rat prostate.     

A highly multiplexed quantitative phosphosite assay for biology and preclinical studies

Reliable methods to quantify dynamic signaling changes across diverse pathways are needed to better understand the effects of disease and drug treatment in cells and tissues but are presently lacking. Here, we present SigPath, a targeted mass spectrometry (MS) assay that measures 284 phosphosites in 200 phosphoproteins of biological interest. SigPath probes a broad swath of signaling biology with high throughput and quantitative precision. We applied the assay to investigate changes in phospho‐signaling in drug‐treated cancer cell lines, breast cancer preclinical models, and human medulloblastoma tumors. In addition to validating previous findings, SigPath detected and quantified a large number of differentially regulated phosphosites newly associated with disease models and human tumors at baseline or with drug perturbation. Our results highlight the potential of SigPath to monitor phosphoproteomic signaling events and to nominate mechanistic hypotheses regarding oncogenesis, response, and resistance to therapy.     

X-ray structures of Sap1 and Sap5: structural comparison of the secreted aspartic proteinases from Candida albicans

Proteolytic activity is an important virulence factor for Candida albicans (C. albicans). It is attributed to the family of the secreted aspartic proteinases (Saps) from C. albicans with a minimum of 10 members. Saps show controlled expression and regulation for the individual stages of the infection process. Distinct isoenzymes can be responsible for adherence and tissue damage of local infections, while others cause systemic diseases. Earlier, only the structures of Sap2 and Sap3 were known. In our research, we have now succeeded in solving the X-ray crystal structures of the apoenzyme of Sap1 and Sap5 in complex with pepstatin A at 2.05 and 2.5 A resolution, respectively. With the structure of Sap1, we have completed the set of structures of isoenzyme subgroup Sap1-3. Of subgroup Sap4-6, the structure of the enzyme Sap5 is the first structure that has been described up to now. This facilitates comparison of structural details as well as inhibitor binding modes among the different subgroup members. Structural analysis reveals a highly conserved overall secondary structure of Sap1-3 and Sap5. However, Sap5 clearly differs from Sap1-3 by its electrostatic overall charge as well as through structural conformation of its entrance to the active site cleft. Design of inhibitors specific for Sap5 should concentrate on the S4 and S3 pockets, which significantly differ from Sap1-3 in size and electrostatic charge. Both Sap1 and Sap5 seem to play a major part in superficial Candida infections. Determination of the isoenzymes' structures can contribute to the development of new Sap-specific inhibitors for the treatment of superficial infections with a structure-based drug design program.     

Influences of dietary soy isoflavones on metabolism but not nociception and stress hormone responses in ovariectomized female rats

Background  

Isoflavones, the most abundant phytoestrogens in soy foods, are structurally similar to 17beta-estradiol. Few studies have examined the nociception and stress hormone responses after consumption of soy isoflavones.     

Leaf-rust resistance in rye (<Emphasis Type="Italic">Secale cereale</Emphasis> L.). 1. Genetic analysis and mapping of resistance genes <Emphasis Type="Italic">Pr1</Emphasis> and <Emphasis Type="Italic">Pr2</Emphasis>

Genetic analysis of resistance to leaf rust in rye (Puccinia recondita f. sp. secalis) led to the identification of two dominant resistance genes, Pr1 and Pr2. Both genes proved to be effective against a local leaf-rust population as well as a subset of single-pustule isolates (SPIs) the latter of which comprised SPIs with very high virulence complexity. Resistance conferred by Pr1 and Pr2 was expressed in detached-leaf tests of seedlings as well as in field tests of adult plants. Molecular marker analysis allowed us to map Pr1 in the proximal part of rye chromosome 6RL, whereas Pr2 was assigned to the distal part of chromosome 7RL. These results are discussed in view of homoeology relationships among Triticeae. A proposal is submitted for the designation of resistance genes to rye leaf rust which would avoid interference with existing gene-symboling in respect to wheat leaf-rust resistances introgressed from rye into wheat or triticale.     

The crystal structure of the secreted aspartic proteinase 3 from Candida albicans and its complex with pepstatin A

The family of secreted aspartic proteinases (Sap) encoded by 10 SAP genes is an important virulence factor during Candida albicans (C. albicans) infections. Antagonists to Saps could be envisioned to help prevent or treat candidosis in immunocompromised patients. The knowledge of several Sap structures is crucial for inhibitor design; only the structure of Sap2 is known. We report the 1.9 and 2.2 A resolution X-ray crystal structures of Sap3 in a stable complex with pepstatin A and in the absence of an inhibitor, shedding further light on the enzyme inhibitor binding. Inhibitor binding causes active site closure by the movement of a flap segment. Comparison of the structures of Sap3 and Sap2 identifies elements responsible for the specificity of each isoenzyme.     

Total antioxidant capacity – a novel early bio-chemical marker of oxidative stress in HIV infected individuals

Background  

Oxidative stress induced by the production of reactive oxygen species may play a critical role in the stimulation of HIV replication and the development of immunodeficiency. This study was conducted as there are limited and inconclusive studies on the significance of a novel early marker of oxidative stress which can reflect the total antioxidant capacity in HIV patients,