Responses of photosynthetic organisms to sulfur starvation include (i) increasing the capacity of the cell for transporting and/or assimilating exogenous sulfate, (ii) restructuring cellular features to conserve sulfur resources, and (iii) modulating metabolic processes and rates of cell growth and division. We used microarray analyses to obtain a genome-level view of changes in mRNA abundances in the green alga Chlamydomonas reinhardtii during sulfur starvation. The work confirms and extends upon previous findings showing that sulfur deprivation elicits changes in levels of transcripts for proteins that help scavenge sulfate and economize on the use of sulfur resources. Changes in levels of transcripts encoding members of the light-harvesting polypeptide family, such as LhcSR2, suggest restructuring of the photosynthetic apparatus during sulfur deprivation. There are also significant changes in levels of transcripts encoding enzymes involved in metabolic processes (e.g., carbon metabolism), intracellular proteolysis, and the amelioration of oxidative damage; a marked and sustained increase in mRNAs for a putative vanadium chloroperoxidase and a peroxiredoxin may help prolong survival of C. reinhardtii during sulfur deprivation. Furthermore, many of the sulfur stress-regulated transcripts (encoding polypeptides associated with sulfate uptake and assimilation, oxidative stress, and photosynthetic function) are not properly regulated in the sac1 mutant of C. reinhardtii, a strain that dies much more rapidly than parental cells during sulfur deprivation. Interestingly, sulfur stress elicits dramatic changes in levels of transcripts encoding putative chloroplast-localized chaperones in the sac1 mutant but not in the parental strain. These results suggest various strategies used by photosynthetic organisms during acclimation to nutrient-limited growth.Sulfur (S) is an essential element present in proteins, lipids, and various metabolites. It is critical for the association of metal ions to proteins (electron carriers and redox controllers) and is a component of metabolites that function in photoprotection (14, 29) and signal transduction (such as in symbiosis) (45). Because most organisms have limited S storage, their growth and development is dependent upon a continuous supply of this nutrient from the environment. The majority of accessible S in soil solutions is in the form of the SO 4 2Ϫ anion. However, in some cases the majority of soil SO 4 2Ϫ may not be readily available to the biota, since the SO 4 2Ϫ anion is often complexed with cations as insoluble salts that are tightly adsorbed onto the surface of soil particles or exists as a soluble anion that rapidly leaches through the soil matrix. Furthermore, a large proportion of soil SO 4 2Ϫ may be covalently bonded to organic molecules in the form of sulfate esters and sulfonates.The acquisition of SO 4 2Ϫ by plants and microorganisms is facilitated by specific transport systems. Following uptake, the anion is either used for the direct sulfation of compounds or...

The performance of DW imaging was equivalent to that of enhancement ratio in the characterization of T1 hyperintense renal lesions, with both methods having lower sensitivity than image subtraction without reaching significance.

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Graphical abstract

Hyperglycemic conditions impair DMVEC proliferation and tube formation. SP mitigates the effect of hyperglycemia on DMVECs by increasing DMVEC proliferation and tube formation. These findings are not likely to be related to a dysregulation of IL-8 due to the lack of effects of hyperglycemia on IL-8 expression and the lack of effect of IL-8 on DMVEC proliferation and tube formation. The effect of SP on DMVECs makes SP a promising potential target for therapy in impaired wound healing in diabetes, but the exact mechanism remains unknown.

Environmental certification and consumer awareness programs are designed to create market incentives for implementing fisheries and aquaculture practices that are more sustainable. Typically focused on particular species and activities, such programs have so far triggered few changes to improve seafood sustainability. Here, we present a conceptual, system‐wide fisheries and aquaculture certification program designed to recognize and promote change toward more sustainable and resilient seafood production systems. In contrast to previous efforts, this program concentrates on both ecosystems and various human stakeholders, relies on an adaptive management approach (termed “continual improvement”) to enhance outcomes, and considers socioeconomic factors. The goal of this program is to support the restoration and maintenance of healthy ecosystem states and thriving human communities as well as the improvement of whole social–ecological systems.

The post-translational processing of pro-opiomelanocortin (POMC) in brain remains controversial. Classically, there was thought to be a single cell group in the arcuate nucleus with long projections through limbic structures. More recently, a second cell group was discovered in the caudal medulla. This study addresses the question of POMC processing in this region. Steady-state analysis of acid extracts of dorsal caudal medulla from rat and guinea pig CNS by gel filtration chromatography and radioimmunoassay indicated that in both species the major POMC-related end products are alpha-MSH-sized material and beta-endorphin-sized. In this tissue beta-LPH and ACTH represent minor end products. Analysis of the alpha-MSH-sized material from both species by reverse-phase HPLC indicated that in the rat caudal medulla approximately 79% of the alpha-MSH-related material is acetylated, and in the guinea pig caudal medulla approximately 85% of the alpha-MSH-related material is acetylated. Analysis of the forms of beta-endorphin isolated from the rat caudal medulla by cation exchange chromatography revealed that acetylated and non-acetylated forms of beta-endorphin are present in this region of the rat CNS. Approximately 65% of the beta-endorphin in the rat caudal medulla is N-acetylated. Analysis of the forms of beta-endorphin isolated from the guinea pig caudal medulla indicated that approximately 63% of the beta-endorphin is N-acetylated in this region of the guinea pig CNS. These data indicate that the post-translational processing of POMC in the dorsal caudal medulla, the site of the nucleus tractus solitarius POMC cell group, is distinct from the processing patterns that have been reported for POMC systems in the mammalian anterior pituitary, intermediate pituitary and arcuate nucleus.

The availability of genome sequences makes it possible to develop microarrays that can be used for profiling gene expression over developmental time, as organisms respond to environmental challenges, and for comparison between wild-type and mutant strains under various conditions. The desired characteristics of microarrays (intense signals, hybridization specificity and extensive coverage of the transcriptome) were not fully met by the previous Chlamydomonas reinhardtii microarray: probes derived from cDNA sequences (approximately 300 bp) were prone to some nonspecific cross-hybridization and coverage of the transcriptome was only approximately 20%. The near completion of the C. reinhardtii nuclear genome sequence and the availability of extensive cDNA information have made it feasible to improve upon these aspects. After developing a protocol for selecting a high-quality unigene set representing all known expressed sequences, oligonucleotides were designed and a microarray with approximately 10,000 unique array elements (approximately 70 bp) covering 87% of the known transcriptome was developed. This microarray will enable researchers to generate a global view of gene expression in C. reinhardtii. Furthermore, the detailed description of the protocol for selecting a unigene set and the design of oligonucleotides may be of interest for laboratories interested in developing microarrays for organisms whose genome sequences are not yet completed (but are nearing completion).