Diatom Proteomics Reveals Unique Acclimation Strategies to Mitigate Fe Limitation

Phytoplankton growth rates are limited by the supply of iron (Fe) in approximately one third of the open ocean, with major implications for carbon dioxide sequestration and carbon (C) biogeochemistry. To date, understanding how alteration of Fe supply changes phytoplankton physiology has focused on traditional metrics such as growth rate, elemental composition, and biophysical measurements such as photosynthetic competence (Fv/Fm). Researchers have subsequently employed transcriptomics to probe relationships between changes in Fe supply and phytoplankton physiology. Recently, studies have investigated longer-term (i.e. following acclimation) responses of phytoplankton to various Fe conditions. In the present study, the coastal diatom, Thalassiosira pseudonana, was acclimated (10 generations) to either low or high Fe conditions, i.e. Fe-limiting and Fe-replete. Quantitative proteomics and a newly developed proteomic profiling technique that identifies low abundance proteins were employed to examine the full complement of expressed proteins and consequently the metabolic pathways utilized by the diatom under the two Fe conditions. A total of 1850 proteins were confidently identified, nearly tripling previous identifications made from differential expression in diatoms. Given sufficient time to acclimate to Fe limitation, T. pseudonana up-regulates proteins involved in pathways associated with intracellular protein recycling, thereby decreasing dependence on extracellular nitrogen (N), C and Fe. The relative increase in the abundance of photorespiration and pentose phosphate pathway proteins reveal novel metabolic shifts, which create substrates that could support other well-established physiological responses, such as heavily silicified frustules observed for Fe-limited diatoms. Here, we discovered that proteins and hence pathways observed to be down-regulated in short-term Fe starvation studies are constitutively expressed when T. pseudonana is acclimated (i.e., nitrate and nitrite transporters, Photosystem II and Photosystem I complexes). Acclimation of the diatom to the desired Fe conditions and the comprehensive proteomic approach provides a more robust interpretation of this dynamic proteome than previous studies

Genetic counselling for psychiatric disorders: accounts of psychiatric health professionals in the United Kingdom

Genetic counselling is not routinely offered for psychiatric disorders in the United Kingdom through NHS regional clinical genetics departments. However, recent genomic advances, confirming a genetic contribution to mental illness, are anticipated to increase demand for psychiatric genetic counselling. This is the first study of its kind to employ qualitative methods of research to explore accounts of psychiatric health professionals regarding the prospects for genetic counselling services within clinical psychiatry in the UK. Data were collected from 32 questionnaire participants, and 9 subsequent interviewees. Data analysis revealed that although participants had not encountered patients explicitly demanding psychiatric genetic counselling, psychiatric health professionals believe that such a service would be useful and desirable. Genomic advances may have significant implications for genetic counselling in clinical psychiatry even if these discoveries do not lead to genetic testing. Psychiatric health professionals describe clinical genetics as a skilled profession capable of combining complex risk communication with much needed psychosocial support. However, participants noted barriers to the implementation of psychiatric genetic counselling services including, but not limited to, the complexities of uncertainty in psychiatric diagnoses, patient engagement and ethical concerns regarding limited capacity

Increasing seed oil content in oil-seed rape (Brassica napus L.) by over-expression of a yeast glycerol-3-phosphate dehydrogenase under the control of a seed-specific promoter.

Previous attempts to manipulate oil synthesis in plants have mainly concentrated on the genes involved in the biosynthesis and use of fatty acids, neglecting the possible role of glycerol-3-phosphate supply on the rate of triacylglycerol synthesis. In this study, a yeast gene coding for cytosolic glycerol-3-phosphate dehydrogenase (gpd1) was expressed in transgenic oil-seed rape under the control of the seed-specific napin promoter. It was found that a twofold increase in glycerol-3-phosphate dehydrogenase activity led to a three- to fourfold increase in the level of glycerol-3-phosphate in developing seeds, resulting in a 40% increase in the final lipid content of the seed, with the protein content remaining substantially unchanged. This was accompanied by a decrease in the glycolytic intermediate dihydroxyacetone phosphate, the direct precursor of glycerol-3-phosphate dehydrogenase. The levels of sucrose and various metabolites in the pathway from sucrose to fatty acids remained unaltered. The results show that glycerol-3-phosphate supply co-limits oil accumulation in developing seeds. This has important implications for strategies that aim to increase the overall level of oil in commercial oil-seed crops for use as a renewable alternative to petrol

Adaptation to bipolar disorder and perceived risk to children: a survey of parents with bipolar disorder

BACKGROUND: Bipolar disorder (BPD) is a common condition associated with significant morbidity and reduced quality of life. In addition to challenges caused by their mood symptoms, parents affected with BPD harbor concerns about the mental health of their children. Among adult parents who perceive themselves to have BPD, this study aims to examine participants’ coping methods; identify predictors of adaptation; assess parental perceptions of risks for mood disorders among their children; and describe the relationships among illness appraisals, coping, adaptation to one’s own illness, and perceived risk to one’s children. METHODS: Parents who self-identified as having BPD completed a web-based survey that assessed dispositional optimism, coping, perceived illness severity, perceived etiology of BPD, perceived risk to offspring, and adaptation to BPD. Participants had at least one unaffected child who was 30 years of age or below. RESULTS: 266 parents were included in the analysis. 87% of parents endorsed a “somewhat greater” or “much greater” risk for mood disorders in one’s child(ren) than someone without a family history. Endorsing a genetic/familial etiology to BPD was positively correlated with perceived risk for mood disorders in children (r(s) = .3, p < 0.01) and active coping with BDP (r = .2, p < 0.01). Increased active coping (β = 0.4, p < 0.001) and dispositional optimism (β = 0.3, p < 0.001) were positively associated with better adaptation, while using denial coping was negatively associated with adaptation (β = −0.3, p < 0.001). The variables explained 55.2% of the variance in adaptation (F = 73.2, p < 0.001). Coping mediated the effect of perceived illness severity on adaptation. CONCLUSIONS: These data inform studies of interventions that extend beyond symptom management and aim to improve the psychological wellbeing of parents with BPD. Interventions targeted at illness perceptions and those aimed at enhancing coping should be studied for positive effects on adaptation. Parents with BPD may benefit from genetic counseling to promote active coping with their condition, and manage worry about perceived risk to their children