Local coexpression domains in the genome of rice show no microsynteny with Arabidopsis domains

Plant responses to abiotic stress are determined both by the severity of the stress as well as the metabolic status of the plant. Abscisic acid (ABA) is a key component in integrating these various signals and controlling downstream stress responses. By screening for plants with decreased RD29A:LUC expression, we isolated two alleles, glutamate:glyoxylate transferase1-1 (ggt1-1) and ggt1-2, of a mutant with altered ABA sensitivity. In addition to reduced ABA induction of RD29A, ggt1-1 was altered in ABA and stress regulation of Δ ¹ -pyrroline-5-carboxylate synthase, proline dehydrogenase and 9-cis-epoxycarotenoid dioxygenase 3, which encode enzymes involved in Pro and ABA metabolsim, respectively. ggt1-1 also had altered ABA and Pro contents after stress or ABA treatments while root growth and leaf water loss were relatively unaffected. A light-dependent increase in H₂O₂ accumulation was observed in ggt1-1 consistent with the previously characterized role of GGT1 in photorespiration. Treatment with exogenous H₂O₂, as well as analysis of a mutant in nucleoside diphosphate kinase 2 which also had increased H₂O₂ content but is not involved in photorespiration or amino acid metabolism, demonstrated that the greater ABA stimulation of Pro accumulation in these mutants was caused by altered H₂O₂ content as opposed to other metabolic changes. The results suggest that metabolic changes that alter H₂O₂ levels can affect both ABA accumulation and ABA sensitivity. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Genealogical surveys show a high rate of non-paternal surname transmission with regional differences in Argentina

Surnames are a vertically transmitted cultural trait that in Argentina follows the paternal line of descent when the paternity is known. There was a lack of empirical information regarding non-paternal surname transmissions among the general population, so we performed 2,550 genealogical interviews, which included 6,954 surname passes, in different regions of this country. We compared the proportion of non-paternal transmissions between the propositus and parental generation and found no significant difference between them (p < 0.01). Inter-population comparisons allowed us to describe 4 regional groups. We also drew models and simulations to estimate how many generations it would take to find that only half of the population maintained the paternal transmission. The lowest proportion of non-paternal transmission was 7.3%, estimating 9 generations (between 225 and 315 years) to find that, at most, half its population keeps following the paternal transmission; the highest proportion was 23%, taking 3 generations (75–105 years). Our results show a high proportion of unrecognized paternities among the general population, a very quick loss of association between male lineages and surnames, and regional proportions with significant differences between each other.     

Copper phytoextraction in tandem with oilseed production using commercial cultivars and mutant lines of sunflower

Use of sunflower (Helianthus annuus L.) for Cu phytoextraction and oilseed production on Cu-contaminated topsoils was investigated in afield trial at a former wood preservation site. Six commercial cultivars and two mutant lines were cultivated in plots with and without the addition of compost (5% w/w) and dolomitic limestone (0.2% w/w). Total soil Cu ranged from 163 to 1170 mg kg(-1). In soil solutions, Cu concentration varied between 0.16-0.93 mg L(-1). The amendment increased soil pH, reduced Cu exposure and promoted sunflower growth. Stem length, shoot and capitulum biomasses, seed yield, and shoot and leaf Cu concentrations were measured. At low total soil Cu, shoot Cu mineralomass was higher in commercial cultivars, Le., Salut, Energic, and Countri, whereas competition and shading affected morphological traits of mutants. Based on shoot yield (7 Mg DW ha(-1)) and Cu concentration, the highest removal was 59 g Cu ha(-1). At high total soil Cu, shoot Cu mineralomass peaked for mutants (e.g., 52 g Cu ha(-1) for Mutant 1 line) and cultivars Energic and Countri. Energic seed yield (3.9 Mg air-DW ha(-1)) would be sufficient to produce oil Phenotype traits and shoot Cu removal depended on sunflower types and Cu exposure.     

Trypanosomatid RACK1 orthologs show functional differences associated with translation despite similar roles in Leishmania pathogenesis

RACK1 proteins belong to the eukaryote WD40-repeat protein family and function as spatial regulators of multiple cellular events, including signaling pathways, the cell cycle and translation. For this latter role, structural and genetic studies indicate that RACK1 associates with the ribosome through two conserved positively charged amino acids in its first WD40 domain. Unlike RACK1s, including Trypanosoma brucei RACK1 (TbRACK1), only one of these two positively-charged residues is conserved in the first WD40 domain of the Leishmania major RACK1 ortholog, LACK. We compared virulence-attenuated LACK single copy (LACK/-) L. major, with L. major expressing either two LACK copies (LACK/LACK), or one copy each of LACK and TbRACK1 (LACK/TbRACK1), to evaluate the function of these structurally distinct RACK1 orthologs with respect to translation, viability at host temperatures and pathogenesis. Our results indicate that although the ribosome-binding residues are not fully conserved in LACK, both LACK and TbRACK1 co-sedimented with monosomes and polysomes in LACK/LACK and LACK/TbRACK1 L. major, respectively. LACK/LACK and LACK/TbRACK1 strains differed in their sensitivity to translation inhibitors implying that minor sequence differences between the RACK1 proteins can alter their functional properties. While biochemically distinguishable, both LACK/LACK and LACK/TbRACK1 lines were more tolerant of elevated temperatures, resistant to translation inhibitors, and displayed robust pathogenesis in vivo, contrasting to LACK/- parasites.     

Transgenic potato plants with strongly decreased expression of pyrophosphate:fructose-6-phosphate phosphotransferase show no visible phenotype and only minor changes in metabolic fluxes in their tubers

Potato (Solanum tuberosum L.) plants were transformed with antisense constructs to the genes encoding the -and -subunits of pyrophosphate: fructose-6-phosphate phosphotransferase (PEP), their expression being driven by the constitutive CaMV 35S promotor. (i) In several independent transformant lines, PFP expression was decreased by 70–90% in growing tubers and by 88–99% in stored tubers. (ii) The plants did not show any visual phenotype, reduction of growth or decrease in total tuber yield. However, the tubers contained 20–40% less starch than the wild type. Sucrose levels were slightly increased in growing tubers, but not at other stages. The rates of accumulation of sucrose and free hexoses when tubers were stored at 4° C and the final amount accumulated were the same in antisense and wild-type tubers. (iii) Metabolites were investigated at four different stages in tuber life history; growing (sink) tubers, mature tubers, cold-sweetening tubers and sprouting (source) tubers. At all stages, compared to the wild type, antisense tubers contained slightly more hexose-phosphates, two- to threefold less glycerate-3-phosphate and phosphoenolpyruvate and up to four-to fivefold more fructose-2,6-bisphosphate. (iv) There was no accumulation or depletion of inorganic pyrophosphate (PPi), or of UDP-glucose relative to the hexose-phosphates. (v) The pyruvate content was unaltered or only marginally decreased, and the ATP/ADP ratio did not change. (vi) Labelling experiments on intact tubers did not reveal any significant decrease in the unidirectional rate of metabolism of [U-¹⁴C]sucrose to starch, organic acids or amino acids. Stored tubers with an extreme (90%) reduction of PFP showed a 25% decrease in the metabolism of [U¹⁴-C] sucrose. (vii) Metabolism (cycling) of [U-¹⁴C]glucose to surcrose increased 15-fold in discs from growing antisense tubers, compared with growing wild-type tubers. Resynthesis of sucrose was increased by 10–20% when discs from antisense and wild-type tubers stored at 4° C (cold sweetening) were compared. The conversion of [U-¹⁴C]glucose to starch was decreased by about 30% and 50%, respectively. (viii) The randomisation of [1-¹³C]glucose in the glucosyl and fructosyl moieties of sucrose was decreased from 13.8 and 15.7% in the wild type to 3.6 and 3.9% in an antisense transformant. Simultaneously, randomisation in glucosyl residues isolated from starch was reduced from 14.4 to 4.1%. (ix) These results provide evidence that PFP catalyses a readily reversible reaction in tubers, which is responsible for the recycling of label from triose-phosphates to hexose-phosphates, but with the net reaction in the glycolytic direction. The results do not support the notion that PFP is involved in regulating the cytosolic PPi concentration. They also demonstrate that PFP does not control the rate of glycolysis, and that tubers contain exessive capacity to phosphorylate fructose-6-phosphate. The decreased concentration of phosphoenolpyruvate and glycerate-3-phosphate compensates for the decrease of PFP protein by stimulating ATP-dependent phosphofructokinase, and by stimulating fructose-6-phosphate,2-kinase to increase the fructose-2,6-bisphosphate concentration and activate the residual PFP. The decreased starch accumulation is explained as an indirect effect, caused by the increased rate of resynthesis (cycling) of sucrose in the antisense tubers.Abbreviations Fru1,6bisP fructose-1,6-bisphosphate - Fru2,6bisP fructose-2,6-bisphosphate - Fru6P fructose-6-phosphate - Glc1P glucose-1-phosphate - Glc6P glucose-6-phosphate - NMR nuclear magnetic resonance - 3PGA glycerate-3-phosphate - PEP phosphoenolpyruvate - PEP pyrophosphate: fructose-6-phosphate phosphotransferase - PFK phosphofructokinase - UDPGlc UDP glucose - WT wild type This research was supported by the Bundesministerium for Forschung and Technology (M.S., U.S.), the Canadian Research Council (S.C., D.D.), the Agricultural and Food Research Council (R.V.) and Sandoz Agro Ltd. (M.H., M.S.).     

The chicken proinflammatory cytokines interleukin-1beta and interleukin-6: differences in gene structure and genetic location compared with their mammalian orthologues

The genes encoding the chicken proinflammatory cytokines interleukin (IL)-1B and IL-6 were cloned, sequenced and mapped. The exon:intron structure of the coding region of chicken IL1B corresponds almost exactly to those of mammalian IL1B. As yet, we have no evidence for a 5'-UTR non-coding exon equivalent to that found in mammalian IL1B. The exon:intron structure of chicken IL6 differs from those of mammalian IL6, having one exon fewer (the first two exons in mammalian IL6 genes appear to be fused in the chicken gene). We were unable to clone or sequence the promoter of chicken IL1B. The chicken IL6 promoter shares a number of potential regulatory sequences similar to those found in the human IL6 promoter. These putative elements include (5'-3') a glucocorticoid response element (GRE), an AP-1 binding site, an NF-IL-6 binding site (albeit in the reverse orientation), an NF-kappaB binding site, a second AP-1 binding site and a TATAAA box. A further GRE, a cAMP response element and regions with homology to c-fos serum responsive elements or retinoblastoma control elements were absent. Promoter sequence polymorphisms were not identified in eight different inbred chicken lines. A restriction single-stranded conformational polymorphism was identified which enabled chicken IL1B to be genetically mapped to one end of chromosome 2. Chicken IL6 was mapped by fluorescent in situ hybridization also to chromosome 2, at an FLpter of 0.26.     

SNPs in the FCER1A gene region show no association with allergic rhinitis in a Han Chinese population

Background

Immunoglobulin E (IgE) is a central player in the allergic response, and raised total IgE levels are considered as an indicator of atopy or potential development of atopy. A recent genome-wide scan in a German population-based cohort of adults identified the gene encoding the alpha chain of the high affinity receptor for IgE (FCER1A) as a susceptibility locus influencing total serum IgE levels. The aim of this study was to investigate whether the polymorphisms in the FCER1A gene are associated with allergic rhinitis (AR) in a Han Chinese population.

Methodology/Principal Findings

A population of 378 patients with AR and 288 healthy controls was studied. Precise phenotyping of patients was accomplished by means of a questionnaire and clinical examination. Blood was drawn for DNA extraction and total serum immunoglobulin E (IgE) measurement. A total of 16 single nucleotide polymorphisms (SNPs) in FCER1A were selected and individually genotyped. None of the SNPs in the FCER1A showed an association with AR. Similarly, the lack of association was also evident in subgroup analysis for the presence of different allergen sensitivities. None of the selected SNPs in FCER1A was associated with total IgE level.

Conclusions

Although FCER1A presents itself as a good candidate for contributing to total serum IgE, this study failed to find an association between SNPs in the FCER1A gene region and IgE level or AR susceptibility.     

Planarian activity differences when maintained in water pre-treated with magnetic fields: a nonlinear effect

There have been multiple claims that exposing water to a static magnetic field affects its properties which influence living systems. To test this hypothesis, planarian subsequent to dissection were maintained in spring water that had been previously exposed for only one day to one of three (16, 160, or 1,600?G) intensity static magnetic fields or to a reference condition. Although there was no significant difference in regeneration rates over the subsequent seven-day period, there was a statistically significant nonlinear effect for planarian mobility and diffusion rates. Both mobility rates and diffusion velocity of a liquid within the water that had been exposed to the 16?G field was about twice that for water exposed to the other intensities. These results imply that nonlinear biophysical effects may emerge under specific conditions of intensity ranges for particular volumes of water.     

Pediatric trauma: differences in pathophysiology,injury patterns and treatment compared with adult trauma.

Although multiple trauma remains the leading cause of death among children, fewer resources and less attention have been directed to treatment of the injured child than to treatment of the injured adult. Insufficient training of medical personnel and hence lack of expertise in the management of injured children are factors contributing to disability and death in such children. Although the principles of resuscitation of injured children are similar to those for adults, appreciation of the differences in cardiorespiratory variables, airway anatomy, response to blood loss, thermoregulation and equipment required is essential for successful initial resuscitation. Cerebral, abdominal and thoracic injuries account for most of the disability and death among injured children. Cerebral damage may be due to secondary injuries to the brain and is potentially preventable. The need to preserve the spleen in children complicates the management of abdominal trauma. Although children usually have large cardiorespiratory reserves, they are likely to need airway control and ventilation with thoracic injuries. The psychologic effect of trauma may pose long-term problems and needs close follow-up.     

The linkage map of sheep Chromosome 6 compared with orthologous regions in other species

The genetic linkage map of sheep Chromosome (Chr) 6 has been extended to include 35 loci with the addition of 11 RFLP and 12 microsatellite loci. The sex-averaged linkage map now spans 154 cM from phosphodiesterase cyclic GMP beta polypeptide (PDE6B) to OarCP125, an anonymous sheep microsatellite. The male and female map lengths, at 180 cM and 132 cM respectively, did not differ significantly. The physical assignment of PDE6B to Chr 6q33-qter orientates the linkage map on sheep Chr 6 with PDE6B near the telomere and OarCP125 towards the centromere. The order and genetic distances between loci are similar for the sheep Chr 6 and cattle Chr 6 maps, except for the position of the casein genes. The sheep Chr 6 linkage map is also comparable to portions of human Chr 4, mouse Chrs 5 and 3, and pig Chr 8. The synteny between sheep Chr 6 and human Chr 4 has been extended from PDE6B (4p16.3) to epidermal growth factor (EGF, 4q25-q27). However, a region from platelet-derived growth factor receptor α polypeptide (PDGFRA) to bone morphogenetic protein 3 (BMP3), which spans 19 cM on sheep Chr 6, appears to be inverted with respect to the human and mouse loci. Other differences in the gene order between sheep, pig, and mouse suggest more complex rearrangements. Received: 16 August 1995 / Accepted: 12 December 1995     

Temperature-sensitive mutants of the exosome subunit Rrp43p show a deficiency in mRNA degradation and no longer interact with the exosome

Rrp43p is a Saccharomyces cerevisiae exosome subunit involved in pre-rRNA processing which is found both in the nucleus and in the cytoplasm. So far, no function has been assigned to the cytoplasmic fraction of Rrp43p. We have addressed Rrp43p function by analyzing mRNA stability in three rrp43 temperature-sensitive (ts) strains, which carry different ts alleles (rrp43-1, rrp43-2 and rrp43-3), and by analyzing Rrp43p interactions with the remaining exosome subunits. In the ts strains, endogenous mRNAs (ACT1 and PAB1), as well as a heterologous reporter mRNA (CATpG) showed longer half-lives, relative to a control strain carrying wild-type RRP43. The mutants also accumulated a degradation intermediate of the reporter mRNA that is typical of defective mRNA decay. These results allow us to propose that Rrp43p is required for mRNA degradation. Rrp43p interacts with the exosome complex via Rrp46p, as determined by two-hybrid analyses. Interestingly, the rrp43 ts mutant proteins do not interact with Rrp46p, indicating that the ts phenotype may be caused by disruption of the Rrp43p– Rrp46p interaction. The ts strains also showed a pre-rRNA processing defect, which is consistent with previous studies on Rrp43p function.     

Nuclear transport of U1 snRNP in somatic cells: differences in signal requirement compared with Xenopus laevis oocytes

The signal requirement for the nuclear import of U1 RNA in somatic cells from different species was investigated by microinjection of both digoxygenin-labeled wild type and mutant U1 RNA molecules and in vitro reconstituted U1 snRNPs. U1 RNA was shown to be targeted to the nucleus by a temperature-dependent process that requires the prior assembly of RNPs from the common proteins and the microinjected RNA. Competition in the cell between immunoaffinity-purified U1 snRNPs and digoxygenin- labeled U1 snRNPs reconstituted in vitro showed that the transport is saturable and should therefore be a mediated process. The transport of a karyophilic protein under the same conditions was not affected, indicating the existence of a U snRNP-specific transport pathway in somatic cells, as already seen in the Xenopus laevis oocyte system. Surprisingly, the signal requirement for nuclear transport of U1 snRNP was found to differ between oocytes and somatic cells from mouse, monkey and Xenopus, in that the m3GGpppG-cap is no longer an essential signaling component in somatic cells. However, as shown by investigation of the transport kinetics of m3GpppG- and ApppG-capped U1 snRNPs, the m3GpppG-cap accelerates the rate of U1 snRNP import significantly indicating that it has retained a signaling role for nuclear targeting of U1 snRNP in somatic cells. Moreover, our data strongly suggest that cell specific rather than species specific differences account for the differential m3G-cap requirement in nuclear import of U1 snRNPs.