Genetic variation of an odorant receptor OR7D4 and sensory perception of cooked meat containing androstenone

Although odour perception impacts food preferences, the effect of genotypic variation of odorant receptors (ORs) on the sensory perception of food is unclear. Human OR7D4 responds to androstenone, and genotypic variation in OR7D4 predicts variation in the perception of androstenone. Since androstenone is naturally present in meat derived from male pigs, we asked whether OR7D4 genotype correlates with either the ability to detect androstenone or the evaluation of cooked pork tainted with varying levels of androstenone within the naturally-occurring range. Consistent with previous findings, subjects with two copies of the functional OR7D4 RT variant were more sensitive to androstenone than subjects carrying a non-functional OR7D4 WM variant. When pork containing varying levels of androstenone was cooked and tested by sniffing and tasting, subjects with two copies of the RT variant tended to rate the androstenone-containing meat as less favourable than subjects carrying the WM variant. Our data is consistent with the idea that OR7D4 genotype predicts the sensory perception of meat containing androstenone and that genetic variation in an odorant receptor can alter food preferences.     

Selection of transgenic <Emphasis Type="Italic">Petunia</Emphasis> plants using the green fluorescent protein (GFP)

Selectable marker genes are needed for efficient transformation of plants. The present study focused on testing the applicability of green fluorescent protein (GFP) for selecting transgenic Petunia hybrida plants without applying antibiotics or herbicides. Based on a transient gene expression assay, the efficiency of two gfp genes, mGFP-4 and smRS-GFP, was compared. Two days after infiltration of Agrobacterium tumefaciens, GFP expression was recorded in leaf epidermal cells. The intensity of smRS-GFP fluorescence was higher than that of mGFP-4 and easier to distinguish from other unspecific fluorescent signals in Petunia. Transformations using the pMen65smRS-GFP vector, which contained the neomycin phosphotransferase II (nptII) gene, resulted in callus and shoots that visually and clearly expressed detectable GFP levels; in addition, this vector made it possible to exclusively select transformed plants using GFP. The transformation efficiencies achieved by using GFP selection versus combined kanamycin and GFP selection (nptII+GFP) were compared in four Petunia genotypes with a transformation experiment with four replications. In three out of four Petunia cultivars a higher transformation frequency was achieved by using nptII+GFP selection. Southern blot hybridisation revealed single and multiple integrations of smRS-GFP in Petunia. Single copy plants showed intensive expression in all parts of the plants, whereas a higher copy number led to only weak or partial expression of smRS-GFP allowing the visual selection of single copy events. Thus, it is possible to select transgenic Petunia plants based on their GFP expressions without applying antibiotics or herbicides.     

Schizosaccharomyces pombe Ofd2 is a nuclear 2-oxoglutarate and iron dependent dioxygenase interacting with histones

2-Oxoglutarate (2OG) dependent dioxygenases are ubiquitous iron containing enzymes that couple substrate oxidation to the conversion of 2OG to succinate and carbon dioxide. They participate in a wide range of biological processes including collagen biosynthesis, fatty acid metabolism, hypoxic sensing and demethylation of nucleic acids and histones. Although substantial progress has been made in elucidating their function, the role of many 2OG dioxygenases remains enigmatic. Here we have studied the 2OG and iron (Fe(II)) dependent dioxygenase Ofd2 in Schizosaccharomyces pombe, a member of the AlkB subfamily of dioxygenases. We show that decarboxylation of 2OG by recombinant Ofd2 is dependent on Fe(II) and a histidine residue predicted to be involved in Fe(II) coordination. The decarboxylase activity of Ofd2 is stimulated by histones, and H2A has the strongest effect. Ofd2 interacts with all four core histones, however, only very weakly with H4. Our results define a new subclass of AlkB proteins interacting with histones, which also might comprise some of the human AlkB homologs with unknown function.     

TCTP Is an Androgen-Regulated Gene Implicated in Prostate Cancer

TCTP has been implicated in a plethora of important cellular processes related to cell growth, cell cycle progression, malignant transformation and inhibition of apoptosis. In addition to these intracellular functions, TCTP has extracellular functions and plays an important role in immune cells. TCTP expression was previously shown to be deregulated in prostate cancer, but its function in prostate cancer cells is largely unknown. Here we show that TCTP expression is regulated by androgens in LNCaP prostate cancer cells in vitro as well as human prostate cancer xenografts in vivo. Knockdown of TCTP reduced colony formation and increased apoptosis in LNCaP cells, implicating it as an important factor for prostate cancer cell growth. Global gene expression profiling in TCTP knockdown LNCaP cells showed that several interferon regulated genes are regulated by TCTP, suggesting that it may have a role in regulating immune function in prostate cancer. In addition, recombinant TCTP treatment increased colony formation in LNCaP cells suggesting that secreted TCTP may function as a proliferative factor in prostate cancer. These results suggest that TCTP may have a role in prostate cancer development.     

Intimate Partner Violence,Relationship Power Inequity and the Role of Sexual and Social Risk Factors in the Production of Violence among Young Women Who Have Multiple Sexual Partners in a Peri-Urban Setting in South Africa

Introduction

This paper aims to assess the extent and correlates of intimate partner violence (IPV), explore relationship power inequity and the role of sexual and social risk factors in the production of violence among young women aged 16–24 reporting more than one partner in the past three months in a peri-urban setting in the Western Cape, South Africa. Recent estimates suggest that every six hours a woman is killed by an intimate partner in South Africa, making IPV a leading public health problem in the country. While there is mounting evidence that levels of IPV are high in peri-urban settings in South Africa, not much is known about how it manifests among women who engage in concomitantly high HIV risk behaviours such as multiple sexual partnering, transactional sex and age mixing. We know even less about how such women negotiate power and control if exposed to violence in such sexual networks.

Methods

Two hundred and fifty nine women with multiple sexual partners, residing in a predominantly Black peri-urban community in the Western Cape, South Africa, were recruited into a bio-behavioural survey using Respondent Driven Sampling (RDS). After the survey, focus group discussions and individual interviews were conducted among young women and men to understand the underlying factors informing their risk behaviours and experiences of violence.

Findings

86% of the young women experienced IPV in the past 12 months. Sexual IPV was significantly correlated with sex with a man who was 5 years or older than the index female partner (OR 1.7, 95% CI 1.0–3.2) and transactional sex with most recent casual partner (OR 2.1, 95% CI 1.1–3.8). Predictably, women experienced high levels of relationship power inequity. However, they also identified areas in their controlling relationships where they shared decision making power.

Discussion

Levels of IPV among young women with multiple sexual partners were much higher than what is reported among women in the general population and shown to be associated with sexual risk taking. Interventions targeting IPV need to address sexual risk taking as it heightens vulnerability to violence.     

Leupeptin enhances cell surface localization of fibroblast growth factor receptor 1 in adult sensory neurons by increased recycling

Fibroblast growth factors (FGFs) act as trophic factors during development and regeneration of the nervous system. FGFs mediate their responses by activation of four types of FGF receptors (FGFR1-4). FGFR1 is expressed in adult sensory neurons of dorsal root ganglia (DRG), and overexpression of FGFR1 enhances FGF-2-induced elongative axon growth in vitro. Ligand-induced activation of FGFR1 is followed by endocytosis and rapid lysosomal degradation. We previously reported that the lysosomal inhibitor leupeptin prevents degradation of FGFR1 and promotes FGF-2-induced elongative axon growth of DRG neurons overexpressing FGFR1. Therefore, we analyzed the effects of leupeptin on intracellular sorting of FGFR1 in PC12 pheochromocytoma cells and DRG neurons. Leupeptin increased colocalization of FGFR1 with lysosomes. Furthermore, leupeptin enhanced the cell surface localization of FGFR1 by increased receptor recycling and this effect was abolished by the recycling inhibitor monensin. In addition, a lysine mutant of FGFR1, which is preferentially recycled back to the cell surface, promoted elongative axon growth of DRG neurons similar to leupeptin. In contrast, the lysosomal inhibitor bafilomycin had no effect on surface localization of FGFR1, inhibited axon growth of DRG neurons and abolished the effects of leupeptin on receptor recycling. Together, our results strongly imply that increased recycling of FGFR1 promotes axon elongation, but not axonal branching, of adult DRG neurons in vitro.     

Proteomic analyses of somatic and zygotic embryos of Cyclamen persicum Mill. reveal new insights into seed and germination physiology

In the horticulturally important ornamental species Cyclamen persicum Mill., somatic embryogenesis is an efficient vegetative propagation method and the development of artificial seeds is an ultimate aim. This study aims at a systematic comparison of the proteomes of zygotic embryos, somatic embryos grown in liquid medium containing 30 or 60 g l⁻¹ sucrose, germinating embryos of both types and endosperm in order to obtain novel insights into seed and germination physiology. Using high resolution two-dimensional isoelectric focussing/sodium dodecylsulfate polyacrylamide gel electrophoresis (2D IEF/SDS PAGE), 74% of the proteins expressed in zygotic embryos were found in similar abundance in somatic embryos grown in 60 g l⁻¹ sucrose. Somatic embryos grown in 30 g l⁻¹ sucrose accumulated fewer protein species than those grown in 60 g l⁻¹. Selected proteins were identified following mass spectrometry (nano-LC-MS/MS). Four enzymes involved in glycolysis (UDP-glucose pyrophosphorylase, fructose bisphosphate aldolase, triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase GAPDH) were specifically induced in somatic embryos. 11S globulin proteins identified by MS were present in high levels in somatic embryos, zygotic embryos and endosperm, whereas 7S globulins were detected mainly in endosperm and zygotic embryos. These are the first storage proteins identified in C. persicum. Xyloglucans are known to be another group of seed storage compounds in C. persicum. Interestingly, xyloglucan endotransglycosylases were found to be highly expressed in endosperm tissue. We discuss the physiological implications of these observations.     

TDZ induces shoot regeneration in various Kalanchoë blossfeldiana Poelln. cultivars in the absence of auxin

In order to optimize shoot regeneration in Kalancho? blossfeldiana, leaf and internode explants of seven cultivars including one inter-specific were studied. The effects of various combinations of α-naphthalene acetic acid (NAA) (0, 0.57 M) and thidiazuron (TDZ) (0, 0.45, 4.5, 22.5, 67.5 μM) on MS medium were examined. In all cultivars shoot regeneration frequency and number of shoots per explant were enhanced by increasing TDZ concentration. Supplementing the media with NAA did not improve shoot regeneration. Maximum regeneration frequency and optimum concentration of TDZ for shoot regeneration depended significantly on the cultivar. Internode explants, but not leaf explants, of some cultivars, were able to produce adventitious shoots without treatment with growth regulator.