Growth hormone locus expands and diverges after the separation of New and Old World Monkeys

While most mammals including the prosimians have a single copy of the growth hormone (GH) gene, anthropoids possess a cluster of GH-related genes. Throughout the evolution of the main anthropoid groups [New World Monkeys (NWM), Old World Monkeys (OWM), and apes], two features stand out of the GH loci. The first is the appearance of chorionic somatommamotropin hormone (CSH) genes within the OWM lineage and the second is the expansion of the loci intergenic regions in the OWM and apes. In relation with this loci expansion, the NWM possess intergenic regions of homogeneous lengths (3.5 kb). In contrast, heterogeneous lengths (6 and 13 kb) have been reported for species of the OWM. At the present, none of the OWM genomic GH loci organizations have been described. Here, we report the genomic organization of the GH locus in the rhesus monkey, this locus has six GH-related genes separated by five intergenic regions. The 5' end gene (GH-1) encodes for the pituitary GH and is followed by CSH-1, GH-2, CSH-2, CSH-3 and CSH-4 genes. The five intergenic regions have heterogeneous lengths and also present more or less the same Alu distribution as the human GH locus. To analyze the events that contributed to the extension of the intergenic regions of the GH locus and the emergence of the regulatory elements, the five GH locus intergenic regions of the spider monkey (NWM) were sequenced. The results of comparing the loci from both species suggest that the long intergenic regions (13 kb) of the rhesus GH locus share a common ancestor with the 3.5 kb intergenic regions of the spider monkey. However, the observed increased length of the former is due to an insertion (approximately 8.7 kb) at their 3' end. Interestingly in this insert, we discovered a DNA element resembling the enhancer of the CSH genes of the human GH locus. On the other hand, we observed that the short intergenic regions (6 kb) increased by a different recombination event.     

Phylogenetic relationships and phylogeography of the Killifish species of the subgenus Chromaphyosemion (Radda, 1971) in West Africa, inferred from mitochondrial DNA sequences

We have analyzed the phylogenetic relationships of 160 specimens from 88 samples representing all defined species of the African Aplocheiloid subgenus Chromaphyosemion in order to examine the monophyly of this group, the species interrelationships, and to reveal trends in chromosomal evolution and formulate hypotheses about their evolutionary history. The data set comprised 1153 total nucleotides from the mitochondrial 12S rRNA, cytochrome oxidase I, and D-loop. The molecular-based topologies were analyzed by maximum parsimony, maximum likelihood, distance method and Bayesian inference support the monophyly of the subgenus Chromaphyosemion. All populations with ambiguous taxonomic status were assigned to an already described species except A. sp. Rio Muni which corresponds to a still undescribed species. Aphyosemion alpha and A. lugens were in basal position in the different trees that indicate a possible origin of the subgenus Chromaphyosemion in the South Cameroon-North Gabon region. Furthermore, the South Cameroon region (between 2 degrees and 3 degrees of North latitude) that accommodates half of the Chromaphyosemion species is considered to have been a refuge zone during the late quaternary dry events that Africa experienced. Phylogenetic relationships among the subgenus also revealed that chromosomal evolution is complex and should be studied at the intraspecific level.     

Quantifying and Exploring Strategic Regional Priorities for Managing Natural Capital and Ecosystem Services Given Multiple Stakeholder Perspectives

A ubiquitous problem for community-based regional environmental agencies is to set strategic management priorities among a myriad of issues and multiple stakeholder perspectives. Here, we quantify the strategic management priorities for natural capital and ecosystem services using multicriteria decision analysis (MCDA) in a case study of the South Australian Murray-Darling Basin Natural Resources Management Board (the Board) region. A natural capital and ecosystem services framework was tailored to present decision-makers with a range of potential issues for strategic consideration as goal hierarchies in MCDA. Priorities were elicited from the Board and its four regionally based consultative groups using the Analytical Hierarchy Process and swing weights. Centered log ratio transformed weights were analyzed using multiple pairwise ANOVA comparisons (Dunnett’s T3) and hierarchical cluster analysis. Substantial variation in priorities occurred between decision-makers. Nonetheless, analysis of priorities for assets and services robustly demonstrated that water was the highest priority, followed by land, then biota, with atmosphere the lowest priority. Decision-makers also considered that environmental management should not impact negatively on built or social capital. Few significant differences in priorities were found between decision-maker groups. However, clusters of manager types were found which represent distinct alternative management strategies, notably the prioritization of either intermediate or final ecosystem services. The results have implications for regional environmental decision-making and suggest that embracing variation in perspectives may be a better way forward for multistakeholder MCDA. The study operationalizes natural capital and ecosystem services by providing strategic priorities for targeting management and policy within the context of community-based, regional environmental management.     

Is the German suspension of MON810 maize cultivation scientifically justified?

We examined the justifications invoked by the German government in April 2009 to suspend the cultivation of the genetically modified maize varieties containing the Bt insect-resistance trait MON810. We have carried out a critical examination of the alleged new data on a potential environmental impact of these varieties, namely two scientific papers describing laboratory force-feeding trials on ladybirds and daphnia, and previous data on Lepidoptera, aquatic and soil organisms. We demonstrate that the suspension is based on an incomplete list of references, ignores the widely admitted case-by-case approach, and confuses potential hazard and proven risk in the scientific procedure of risk assessment. Furthermore, we did not find any justification for this suspension in our extensive survey of the scientific literature regarding possible effects under natural field conditions on non-target animals. The vast majority of the 41 articles published in 2008 and 2009 indicate no impact on these organisms and only two articles indicate a minor effect, which is either inconsistent during the planting season or represents an indirect effect. Publications from 1996 to 2008 (376 publications) and recent meta-analyses do not allow to conclude on consistent effects either. The lower abundance of some insects concerns mainly specialized enemies of the target pest (an expected consequence of its control by Bt maize). On the contrary, Bt maize have generally a lower impact than insecticide treatment. The present review demonstrates that the available meta-knowledge on Cry1Ab expressing maize was ignored by the German government which instead used selected individual studies.     

Absence of the steroid receptor coactivator-3 induces B-cell lymphoma

Steroid receptor coactivator 3 (SRC-3/ACTR/AIB-1/pCIP/RAC3/TRAM-1) is a member of the p160 family of nuclear receptor coactivators that plays an important role in mammary gland growth, development, and tumorigenesis. We show that deletion of SRC-3 gene decreases platelet and increases lymphocytes numbers, leading to the development of malignant B-cell lymphomas upon aging. The expansion of the lymphoid lineage in SRC-3(-/-) mice is cell autonomous, correlates with an induction of proliferative and antiapoptotic genes secondary to constitutive NF-kappaB activation, and can be reversed by restoration of SRC-3 expression. NF-kappaB activation is explained by the degradation of IkappaB, consequent to increases in free IkappaB kinase, which is no longer inhibited by SRC-3. These results demonstrate that SRC-3 regulates lymphopoiesis and in combination with previous studies indicate that SRC-3 has vastly diverging effects on cell proliferation depending on the cellular context, ranging from proliferative and tumorigenic (breast) to antiproliferative (lymphoid cells) effects.     

Formation of the ascidian epidermal sensory neurons: insights into the origin of the chordate peripheral nervous system

The vertebrate peripheral nervous system (PNS) originates from neural crest and placodes. While its developmental origin is the object of intense studies, little is known concerning its evolutionary history. To address this question, we analyzed the formation of the larval tail PNS in the ascidian Ciona intestinalis. The tail PNS of Ciona is made of sensory neurons located within the epidermis midlines and extending processes in the overlying tunic median fin. We show that each midline corresponds to a single longitudinal row of epidermal cells and neurons sharing common progenitors. This simple organization is observed throughout the tail epidermis, which is made of only eight single-cell rows, each expressing a specific genetic program. We next demonstrate that the epidermal neurons are specified in two consecutive steps. During cleavage and gastrula stages, the dorsal and ventral midlines are independently induced by FGF9/16/20 and the BMP ligand ADMP, respectively. Subsequently, Delta/Notch–mediated lateral inhibition controls the number of neurons formed within these neurogenic regions. These results provide a comprehensive overview of PNS formation in ascidian and uncover surprising similarities between the fate maps and embryological mechanisms underlying formation of ascidian neurogenic epidermis midlines and the vertebrate median fin.     

Arabidopsis Putative Selenium-Binding Protein1 Expression Is Tightly Linked to Cellular Sulfur Demand and Can Reduce Sensitivity to Stresses Requiring Glutathione for Tolerance

Selenium-Binding Protein1 (SBP1) gene expression was studied in Arabidopsis (Arabidopsis thaliana) seedlings challenged with several stresses, including cadmium (Cd), selenium {selenate [Se(VI)] and selenite [Se(IV)]}, copper (Cu), zinc (Zn), and hydrogen peroxide (H₂O₂) using transgenic lines expressing the luciferase (LUC) reporter gene under the control of the SBP1 promoter. In roots and shoots of SBP1∷LUC lines, LUC activity increased in response to Cd, Se(VI), Cu, and H₂O₂ but not in response to Se(IV) or Zn. The pattern of expression of SBP1 was similar to that of PRH43, which encodes the 5′-Adenylylphosphosulfate Reductase2, a marker for the induction of the sulfur assimilation pathway, suggesting that an enhanced sulfur demand triggers SBP1 up-regulation. Correlated to these results, SBP1 promoter showed enhanced activity in response to sulfur starvation. The sulfur starvation induction of SBP1 was abolished by feeding the plants with glutathione (GSH) and was enhanced when seedlings were treated simultaneously with buthionine sulfoxide, which inhibits GSH synthesis, indicating that GSH level participates in the regulation of SBP1 expression. Changes in total GSH level were observed in seedlings challenged with Cd, Se(VI), and H₂O₂. Accordingly, cad2-1 seedlings, affected in GSH synthesis, were more sensitive than wild-type plants to these three stresses. Moreover, wild-type and cad2-1 seedlings overexpressing SBP1 showed a significant enhanced tolerance to Se(VI) and H₂O₂ in addition to the previously described resistance to Cd, highlighting that SBP1 expression decreases sensitivity to stress requiring GSH for tolerance. These results are discussed with regard to the potential regulation and function of SBP1 in plants.The highly conserved sequences of selenium-binding proteins (SBPs) among diverse species and kingdoms suggest that SBPs share a fundamental biological role (Agalou et al., 2005). SBP1 was first characterized in mouse liver as a ⁷⁵selenium (Se)-binding protein in experiments designed to identify selenoproteins (Bansal et al., 1990). In mammals, Se is an essential nutrient. It is incorporated in the selenoamino acid Se-Cys, which is required for the translation of several proteins involved in cell defense or hormone regulation (Behne and Kyriakopoulos, 2001; Papp et al., 2007), and can as well be bound by binding proteins such as SBP1 (Bansal et al., 1990). Although a physiological function has not yet been assigned to SBP1, its involvement in detoxification mechanisms is largely suggested. Down-regulation of SBP1 expression is correlated with rapid tumor development in many organs (Kim et al., 2006; Stammer et al., 2008), and recently, SBP1 was characterized as a biomarker for schizophrenia (Glatt et al., 2005). Moreover, its homolog SBP2 is suggested to play a protective role as a scavenger of toxic electrophiles or oxidant species (Lanfear et al., 1993; Cohen et al., 1997; Mattow et al., 2006). Other functions, such as intra-Golgi protein transport, have been assigned to mammalian SBP (Porat et al., 2000).To date, Se has not been demonstrated to be essential in land plants, but a Se-containing glutathione (GSH) peroxidase has been isolated from Chlamydomonas reinhardtii (Fu et al., 2002). Except at low concentration, where it can have a positive effect on plant growth, Se is highly toxic. Se toxicity results from its chemical similarity with sulfur (S), leading to nonspecific replacement of S by Se in proteins and other S compounds (White et al., 2004; Sors et al., 2005). Se is taken up by roots from the soil mostly in inorganic forms {selenate [Se(VI)] or selenite [Se(IV)]} and then converted to organic forms that can accumulate in plant tissues or be volatilized in the atmosphere (Terry et al., 2000; Ellis and Salt, 2003). Mechanisms of Se tolerance in plants could be achieved by the conversion of selenoamino acids into their methylated forms, nonincorporable into proteins, or by compartmentalization into vacuoles in organic or inorganic forms (Lauchli, 1993; Nakamuro et al., 2000). SBP may participate in Se tolerance, as Arabidopsis (Arabidopsis thaliana) plants overexpressing SBP1 have increased resistance to Se(IV) (Agalou et al., 2005).In a previous study, we showed that SBP1 protein accumulated in response to cadmium (Cd) in Arabidopsis cultured cells and plants (Sarry et al., 2006; Dutilleul et al., 2008). SBP1 overexpression led to enhanced tolerance to Cd in Arabidopsis, suggesting that SBP1 may represent a new detoxification mechanism that plants use to face heavy metal toxicity, possibly through direct binding to the metal (Dutilleul et al., 2008). Besides its involvement in response to metal and metalloid stresses, data suggest other functions. For example, in Lotus japonicus, SBP1 was reported to be involved in nodule formation and function (Flemetakis et al., 2002). In rice (Oryza sativa), overexpression of SBP1 led to enhanced tolerance against different pathogens (Sawada et al., 2004).In the Arabidopsis genome, three SBP genes are present. SBP1 appeared to be the most expressed gene in healthy plants and in response to stress (Dutilleul et al., 2008). We showed that SBP1 was ubiquitously expressed in nonstressed conditions, notably in actively growing tissues and during seed development, highlighting the dynamic regulation of SBP1 expression during development as well (Dutilleul et al., 2008). To get a better understanding of SBP1 protein function in plants, the main goal of this article was to analyze SBP1 promoter activity in response to different stresses and to highlight signals that may regulate its expression. Expression analysis using luciferase (LUC) imaging showed that SBP1 and PRH43, which encodes 5′-Adenylylphosphosulfate Reductase2, a marker for the induction of the S assimilation pathway, were similarly regulated by the different stresses and highly induced in response to S starvation (−S). In addition, SBP1-overexpressing plants showed increased tolerance to stress affecting the GSH level. These results are discussed together with the potential function of SBP1 in plants.     

Effect of low doses of 14 MeV neutrons on polymers

The structural modifications of polymers irradiated with 14 MeV neutrons were studied. Two elastomers, a polypropylene-type polymer and poly(ethylene oxide) were exposed to low doses of fast neutrons in the range of 0.3-14 Gy. The radiation damages were observed at the molecular scale by infrared spectroscopy. The morphological changes were investigated by steric exclusion chromatography, insoluble fraction measurements, differential scanning calorimetry and X-ray diffraction. It was found that neutrons provoked oxidation processes accompanied by modifications in the polymer architecture, including chain scissions, crosslinking reactions and changes in the crystallinity. Moreover, the conventional antioxidants were shown to be inefficient in inhibiting the aging of the polymers. These results also suggest that the radiation damages could be used successfully for dosimetry applications using an easily implementable protocol.