Nutrition, Epigenetics, and Diseases

Increasing epidemiological evidence suggests that maternal nutrition and environmental exposure early in development play an important role in susceptibility to disease in later life. In addition, these disease outcomes seem to pass through subsequent generations. Epigenetic modifications provide a potential link between the nutrition status during critical periods in development and changes in gene expression that may lead to disease phenotypes. An increasing body of evidence from experimental animal studies supports the role of epigenetics in disease susceptibility during critical developmental periods, including periconceptional period, gestation, and early postnatal period. The rapid improvements in genetic and epigenetic technologies will allow comprehensive investigations of the relevance of these epigenetic phenomena in human diseases

Nucleus accumbens shell moderates preference bias during voluntary choice behavior

The nucleus accumbens (NAc) shell lies anatomically at a critical intersection within the brain's reward system circuitry, however, its role in voluntary choice behavior remains unclear. Rats with electrolytic lesions in the NAc shell were tested in a novel foraging paradigm. Over a continuous two-week period they freely chose among four nutritionally identical but differently flavored food pellets by pressing corresponding levers. We examined the lesion's effects on three behavioral dynamics components: motivation (when to eat), preference bias (what to choose) and persistence (how long to repeat the same choice). The lesion led to a marked increase in the preference bias: i.e., increased selection of the most-preferred choice option, and decreased selection of the others. We found no effects on any other behavioral measures, suggesting no effect on motivation or choice persistence. The results implicate the NAc shell in moderating the instrumental valuation process by inhibiting excessive bias toward preferred choice options.11Ysciessciscopu

Oestrogen replacement therapy reduces total plasma homocysteine and enhances genomic DNA methylation in postmenopausal women

Although oestrogen replacement therapy (ERT), which can affect the risk of major cancers, has been known to reduce total plasma homocysteine concentrations in postmenopausal women, the mechanisms and subsequent molecular changes have not yet been defined. To investigate the effect of ERT on homocysteine metabolism, thirteen healthy postmenopausal women were enrolled in a double-blind, placebo-controlled, randomized, cross-over study consisting of two 8-week long phases, placebo and conjugated equine oestrogen (CEE; 0·625 mg/d). Concentrations of total plasma homocysteine, vitamin B6and serum folate and vitamin B12were measured by conventional methods. Genomic DNA methylation was measured by a new liquid chromatography/MS method and promoter methylation status of the oestrogen receptor (ER)α,ERβandp16genes was analysed by methylation-specific PCR after bisulfite treatment. The CEE phase demonstrated a significantly decreased mean of total plasma homocysteine concentrations compared with the placebo phase (8·08 μmol/l (6·82–9·39)v.9·29 (7·53–11·35),P < 0·05) but there was no difference in the blood concentrations of the three B vitamins. The CEE phase also showed a significantly increased genomic DNA methylation in peripheral mononuclear cells compared with the placebo phase (2·85 (SD0·12) ng methylcytosine/μg DNAv.2·40 ± (SD0·15)P < 0·05). However, there was no difference in promoter methylation in theERα,ERβandp16genes. This study demonstrates that decreased homocysteinaemia by CEE therapy parallels with increased genomic DNA methylation, suggesting a potential new candidate mechanism by which ERT affects the risk of cancers and a possible new candidate biomarker for the oestrogen-related carcinogenesis through folate-related one-carbon metabolism

Older Age and Dietary Folate Are Determinants of Genomic and p16-Specific DNA Methylation in Mouse Colon

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The genetic diversity among strawberry breeding resources based on SSRs

Cultivated strawberry (Fragaria × ananassa Duch.) is a high value horticultural crop. In this study, the genetic diversity of 160 strawberry accessions was determined using five highly polymorphic simple sequence repeat (SSR) markers. Sixty different alleles were identified, with allele frequencies in the range of 0.006 to1. Similarity scores were in the range of 0.034 to 0.963 (average: 0.507). The accessions were categorized into five groups. Group 1 contained two diploid Fragaria vesca species and one unknown accession. Group 2 contained one accession (F x ananassa). Group 3 contained 20 F × ananassa accessions and six unknown accessions. Group 4 contained 48 F. × ananassa accessions, one octaploid Fragaria chiloensis species, and six unknown accessions while Group 5 contained 69 F. × ananassa accessions and six unknown accessions. Accessions within a pedigree were frequently grouped together. A total of 30 novel accessions were categorized alongside existing accessions. These results will allow breeders to develop strategies which incorporate more genetic diversity into new cultivars

Integration Through Redefinition: Revisiting the Role of Negotiators’ Goals

Effective negotiation rests in part on generating integrative agreements, or agreements advancing parties’ interests through generating joint gains. Theorists have outlined multiple possibilities to achieve integrative agreements (Pruitt in Negotiation behaviour, Academic Press, New York, 1981; Carnevale in: Deutsch, Coleman, Marcus (eds) Handbook of conflict resolution: theory and practice, Jossey-Bass, San Francisco, 2006), but negotiation research relies disproportionately on studies of one method of integration—making efficient tradeoffs on existing issues. The current studies examine integration through redefinition—modifying the issues under discussion. Doing so encourages revisiting the role goals play in negotiation. Study 1 found that positive and negative bargaining zones are not just indicators of agreement rates, but also cues to consider redefining issues. Specifically, negative bargaining zones spurred attempts to create value that positive bargaining zones did not. Study 2 found that focusing on interests was useful for redefining issues, whereas focusing on ambitious targets was no better than focusing on reservation points. Implications for negotiation theory are discussed