bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Anabaena sp. strain PCC 7120 asr1734 gene encodes a negative regulator of heterocyst development
Authors: Wu Xiaoqiang , Lee Dong W. , Mella Rodrigo A. , Golden James W. 
Published: May 2007

SummaryThe novel asr1734 gene of Anabaena (Nostoc) sp. strain PCC 7120 inhibited heterocyst development when present in extra copies. Overexpression of asr1734 inhibited heterocyst development in several strains including the wild type and two strains that form multiple contiguous heterocysts (Mch phenotype): a PatS null mutant and a hetRR223W mutant. Overexpression of asr1734 also caused increased nblA messenger RNA levels, and increased loss of autofluorescence in vegetative cells throughout filaments after nitrogen or sulphur depletion. Unlike the wild type, an asr1734 knockout mutant formed 5% heterocysts after a nitrogen shift from ammonium to nitrate, and formed 15% heterocysts and a weak Mch phenotype after step‐down to medium lacking combined nitrogen. After nitrogen step‐down, the asr1734 mutant had elevated levels of ntcA messenger RNA. A green fluorescent protein reporter driven by the asr1734 promoter, Pasr1734‐gfp, was expressed specifically in differentiating proheterocysts and heterocysts after nitrogen step‐down. Strains overexpressing asr1734 and containing PhetR‐gfp or PpatS‐gfp reporters failed to show normal patterned upregulation 24 h after nitrogen step‐down even though hetR expression was upregulated at 6 h. Apparent orthologues of asr1734 are found only in two other filamentous nitrogen‐fixing cyanobacteria, Anabaena variabilis and Nostoc punctiforme.
Cold‐shock‐induced de novo transcription and translation of infA and role of IF1 during cold adaptation
Authors: Giangrossi Mara , Brandi Anna , Giuliodori Anna Maria , Gualerzi Claudio O. , Pon Cynthia L. 
Published: May 2007

Summary Escherichia coli infA is transcribed from two promoters, P1 and P2, into a longer and a shorter mRNA encoding translation initiation factor IF1. Although P1 is intrinsically stronger than P2, the shorter half‐life of its transcripts causes the steady‐state level of the P2 transcript to be substantially higher than that of P1 during growth at 37°C. After cold‐shock, de novo transcription and translation of infA contribute to the transient increase of the IF1/ribosomes ratio, which is partially responsible for translational bias consisting in the preferential translation of cold‐shock mRNAs in the cold. Cold‐stress induction of infA expression is mainly due to the high activity of P1 at low temperature, which is further increased by transcriptional stimulation by CspA and by an increased transcript stability. Furthermore, the longer infA mRNA originating from P1 is preferentially translated at low temperature by the translational machinery of cold‐shocked cells. The increased level of IF1 during cold adaptation is essential for overcoming the higher stability of the 70S monomers at low temperature and for providing a sufficient pool of dissociated 30S subunits capable of initiating translation.
Elongation and gravitropic responses of Arabidopsis roots are regulated by brassinolide and IAA
Authors: KIM TAE‐WUK , LEE SUN MIN , JOO SE‐HWAN , YUN HYE SUP , LEE YEW , KAUFMAN PETER B. , KIRAKOSYAN ARA , KIM SOO‐HWAN , NAM KYOUNG HEE , LEE JUNE SEUNG , CHANG SOO CHUL , KIM SEONG‐KI 
Published: May 2007

ABSTRACTExogenously applied brassinolide (BL) increased both gravitropic curvature and length of primary roots of Arabidopsis at low concentration (10−10 M), whereas at higher concentration, BL further increased gravitropic curvature while it inhibited primary root growth. BRI1‐GFP plants possessing a high steady‐state expression level of a brassinosteroid (BR) receptor kinase rendered the plant's responses to gravity and root growth more sensitive, while BR‐insensitive mutants, bri1‐301 and bak1, delayed root growth and reduced their response to the gravitropic stimulus. The stimulatory effect of BL on the root gravitropic curvature was also enhanced in auxin transport mutants, aux1‐7 and pin2, relative to wild‐type plants, and increasing concentration of auxin attenuated BL‐induced root sensitivity to gravity. Interestingly, IAA treatment to the roots of bri1‐301 and bak1 plants or of plants pretreated with a BL biosynthetic inhibitor, brassinazole, increased their sensitivity to gravity, while these treatments for the BL‐hypersensitive transgenic plants, BRI1‐GFP and 35S‐BAK1, were less effective. Expression of a CYP79B2 gene, encoding an IAA biosynthetic enzyme, was suppressed in BL‐hypersensitive plant types and enhanced in BL‐insensitive or ‐deficient plants. In conclusion, our results indicate that BL interacts negatively with IAA in the regulation of plant gravitropic response and root growth, and its regulation is achieved partly by modulating biosynthetic pathways of the counterpart hormone.
RNAi knockdown of Oryza sativa root meander curling gene led to altered root development and coiling which were mediated by jasmonic acid signalling in rice
Authors: JIANG JIAFU , LI JUNHUA , XU YUNYUAN , HAN YE , BAI YUE , ZHOU GUOXIN , LOU YONGGEN , XU ZHIHONG , CHONG KANG 
Published: May 2007

ABSTRACTJasmonic acid (JA) is a well‐known defence hormone, but its biological function and mechanism in rice root development are less understood. Here, we describe a JA‐induced putative receptor‐like protein (OsRLK, AAL87185) functioning in root development in rice. RNA in situ hybridization revealed that the gene was expressed largely in roots, and a fusion protein showed its localization on the plasma membrane. The primary roots in RNAi transgenic rice plants meandered and curled more easily than wild‐type (WT) roots under JA treatment. Thus, this gene was renamed Oryza sativa root meander curling (OsRMC). The transgenic primary roots were shorter, the number of adventitious roots increased and the number of lateral roots decreased as compared to the WT. As well, the second sheath was reduced in length. Growth of both primary roots and second sheaths was sensitive to JA treatment. No significant change of JA level appeared in the roots between the transgenic rice line and WT. Expression of RSOsPR10, involved in the JA signalling pathway, was induced in transgenic rice. Western blotting revealed OsRMC induced by JA. Our results suggest that OsRMC of the DUF26 subfamily involved in JA signal transduction mediates root development and negatively regulates root curling in rice.
Association of HLA genes with Ankylosing Spondylitis in Han Population of eastern China
Authors: Fang M. , Chen R. , Cai Q. , Duan S. , Lv K. , Cheng N. , Sun S. 
Published: May 2007

AbstractAnkylosing spondylitis (AS) is a chronic inflammatory disorder with a multifactorial genetic basis. HLA‐B27 was reported with the greatest susceptibility to AS but did not act alone. The aim of this study was to search for other gene(s) associated with AS independently of HLA‐B27 using 13 microsatellite markers spanning 1.5 Mb from locus TAP1 to HLA‐Cw and a single‐nucleotide polymorphism marker within NFκBIL1 gene promoter. Genotyping for microsatellites was performed in 175 AS patients of eastern Chinese and 219 ethnically matched healthy controls using polymerase chain reaction with fluorescence‐labelled primers, whereas the SNP marker was genotyped by direct DNA sequencing. Allele as well as haplotype frequencies were compared between cases and controls, and a linkage disequilibrium analysis was performed to estimate the LD relationship between the candidate regions. The frequencies of alleles D6S2811*128, STR_MICA*A5.1 and D6S2672*109, as well as haplotypes D6S2811*128–D6S2927*213–D6S2810*340, D6S2927* 221–D6S2810*350–MICA*A5.1, and D6S2810*350–MICA*A5.1–D6S2800* 136 were significantly increased in B27‐positive AS patients when compared with B27‐positive controls. The results indicated that there may be other gene(s) within the HLA region, especially around locus HLA‐B or HLA‐Cw, with susceptibility to AS independently of HLA‐B27.
Targeted inactivation of the tobacco plastome origins of replication A and B
Authors: Scharff Lars B. , Koop Hans‐Ulrich 
Published: May 2007

SummaryAccording to the Kolodner and Tewari model [Kolodner, R.D. and Tewari, K.K. (1975) Nature, 256, 708.], plastid DNA replication involves displacement‐loop and rolling‐circle modes of replication, which are initiated on a pair of origins of replication (ori). In accordance with the model, such a pair of oris –oriA and oriB– was described in Nicotiana tabacum [Kunnimalaiyaan, M. and Nielsen B.L. (1997b) Nucl. Acids Res. 25, 3681.]. However, as reported previously, both copies of oriA can be deleted without abolishing replication. Deletion of both oriBs was not found [Mühlbauer, S.K. et al. (2002) Plant J. 32, 175.]. Here we describe new ori inactivation lines, in which one oriB is deleted and the other copy is strongly mutated. In addition, lines oriA and oriB were deleted from the same inverted repeat. In contrast to the expectations of the model, neither oriA nor oriB is essential. Some of the deletions led to reduced growth of plants and reduced plastid DNA copy number in later stages of leaf development. The gross structure of plastid DNA was unchanged; however, the location of the ends of branched plastid DNA complexes was different in the inactivation mutants. Taken together, the results indicate that there are additional mechanisms of plastid DNA replication and/or additional origins of replication. These mechanisms seem to be different from those found in eubacteria, which, according to the endosymbiont theory, are the progenitors of plastids.
Mutated TATA‐box/TATA binding protein complementation system for regulated transgene expression in tobacco
Authors: Chaturvedi Chandra Prakash , Lodhi Niraj , Ansari Suraiya A. , Tiwari Siddharth , Srivastava Rakesh , Sawant Samir V. , Tuli Rakesh 
Published: May 2007

SummaryA two‐component expression system was developed to achieve tightly regulated expression of transgenes in plants. One component functioned as an expression module whereas the other functioned as a regulatory module. The expression module comprised a highly expressing TATA‐dependent seed‐specific promoter in which the TATA motif in the core promoter was mutated to TGTA. The regulatory module expressed a mutated general transcription factor TBPm3 that recognized TGTA and initiated transcription. Vectors were designed using component one alone or in combination with component two, and were transformed into tobacco. The TGTA mutation in the TATA‐box completely inactivated the promoter, making component one non‐functional. This non‐functional module became transcriptionally active in the presence of the component two that expressed TBPm3. The reporter gene gusA was expressed from the TGTA‐containing chimeric legumin promoter, in a tightly seed‐specific manner, in transgenic tobacco plants in the presence of TBPm3 that was expressed from a constitutive promoter. The results show that the TGTA and TBPm3 combination can be used to achieve high‐level tissue‐specific expression of TATA‐dependent promoters.
The transcription factor HIG1/MYB51 regulates indolic glucosinolate biosynthesis in Arabidopsis thaliana
Authors: Gigolashvili Tamara , Berger Bettina , Mock Hans‐Peter , Müller Caroline , Weisshaar Bernd , Flügge Ulf‐Ingo 
Published: May 2007

SummaryGlucosinolates are a class of plant secondary metabolites that serve as antiherbivore compounds in plant defence. A previously identified Arabidopsis thaliana activation‐tagged line, displaying altered levels of secondary metabolites, was shown here to be affected in the content of indolic and aliphatic glucosinolates. The observed chemotype was caused by activation of the R2R3‐MYB transcription factor gene HIG1 (HIGH INDOLIC GLUCOSINOLATE 1, also referred to as MYB51). HIG1/MYB51 was shown to activate promoters of indolic glucosinolate biosynthetic genes leading to increased accumulation of indolic glucosinolates. The corresponding loss‐of‐function mutant hig1‐1 contained low levels of glucosinolates. Overexpression of the related transcription factor ATR1/MYB34, which had previously been described as a regulator of indolic glucosinolate and indole‐3‐acetic acid homeostasis, in the hig1‐1 mutant background led to a partial rescue of the mutant chemotype along with a severe high‐auxin growth phenotype. Overexpression of MYB122, another close homologue of HIG1/MYB51, did not rescue the hig1‐1 chemotype, but caused a high‐auxin phenotype and increased levels of indolic glucosinolates in the wild‐type. By contrast, overexpression of HIG1/MYB51 resulted in the specific accumulation of indolic glucosinolates without affecting auxin metabolism and plant morphology. Mechanical stimuli such as touch or wounding transiently induced the expression of HIG1/MYB51 but not of ATR1/MYB34, and HIG1/MYB51 overexpression reduced insect herbivory as revealed by dual‐choice assays with the generalist lepidopteran herbivore, Spodoptera exigua. We hypothesize that HIG1/MYB51 is a regulator of indolic glucosinolate biosynthesis that also controls responses to biotic challenges.
Safety of aerosolized liposomal versus deoxycholate amphotericin B formulations for prevention of invasive fungal infections following lung transplantation: a retrospective study
Authors: Lowry C.M. , Marty F.M. , Vargas S.O. , Lee J.T. , Fiumara K. , Deykin A. , Baden L.R. 
Published: May 2007

Abstract: Background. Nebulized amphotericin B deoxycholate (AmBd) has been used to prevent invasive pulmonary aspergillosis after lung transplantation.Methods. In this retrospective study we compared the safety and tolerability of nebulized AmBd and nebulized liposomal amphotericin B (L‐AmB) in 38 consecutive lung transplant recipients. Progress notes, medication administration records, microbiology, and pulmonary function reports were reviewed. Histologic sections from lung tissue were examined. Plasma amphotericin B levels were measured.Results. A total of 1206 doses of AmBd and 1149 doses of L‐AmB were administered. Eighteen patients received AmBd only, 11 received L‐AmB only, and 9 received the medications sequentially. The total number of complaints vs. the number of doses administered was 1.0% for AmBd‐treated patients and 1.2% for L‐AmB‐treated patients. No differences were observed between the treatment groups on lung biopsy specimens. Plasma amphotericin B levels were <0.2–0.9 μg/mL in AmBd‐treated patients and <0.2 μg/mL in L‐AmB‐treated patients.Conclusions. In lung transplant recipients, both inhaled AmBd and L‐AmB were safe and well tolerated over a large number of medication exposures.
Propofol versus alfentanil to prevent movement responses during uterine curettage
Authors: Seitsonen E. R. J. , Cohen‐Laroque E.‐S. , Van Gils M. J. , Korttila K. T. , Neuvonen P. J. , Yli‐Hankala A. M. 
Published: May 2007

Background:  Propofol anaesthesia is frequently associated with movement responses in non‐paralysed patients. Opioids decrease the probability of movement during noxious stimulation. Heart rate variability and frontal electromyography (EMG), which are related to subcortical functions, may be more closely related than surface electroencephalography (EEG) to movement responses to noxious stimulation.Methods:  Eighty‐two patients scheduled for uterine dilatation and curettage were randomized to receive at the first intra‐operative movement either a supplemental alfentanil bolus, 0.5 mg intravenously, or a supplemental propofol bolus, 0.7 mg/kg intravenously. The incidences of recurring movement during the procedure were compared between the two groups. The associations of a measure of heart rate variability (Anemon index), heart rate, EMG and two EEG variables with movement responses were evaluated.Results:  The incidences of recurring movement were 73% and 38% in the alfentanil and propofol groups, respectively [difference, 35%; 95% confidence interval, 9–56%; P= 0.014 between the groups). The Anemon index, heart rate, EMG and surface EEG variables displayed mainly reactive associations with movement responses.Conclusion:  During uterine curettage under propofol–alfentanil–nitrous oxide anaesthesia, a propofol bolus of 0.7 mg/kg was more effective in preventing the recurrence of movement responses than an alfentanil bolus of 0.5 mg. Several physiological variables may be used to track significant arousal reactions, but not to predict them.
Interpopulation variation in predator foraging behaviour promotes the evolutionary divergence of prey
Authors: TOJU H. 
Published: May 2007

AbstractDespite intensive investigation of the role of predation on evolutionary processes, few studies have questioned the possibility of the evolutionary divergence of prey populations in response to interpopulation variation in predator foraging behaviour. In an interaction between a seed‐predatory insect, the camellia weevil (Curculio camelliae), and its host plant, the Japanese camellia (Camellia japonica), I tested whether the evolutionary differentiation of the plant's defensive trait, pericarp thickness, was related to the interpopulation variation in the foraging behaviour of female weevils. I found that the preference of weevils for the plant fruit based on pericarp thickness varied across 13 populations in Japan. Importantly, variation in weevil behaviour explained interpopulation variation in pericarp thickness and the direction/strength of natural selection on the trait. Overall, I show that adaptive foraging of predators can result in the evolutionary divergence of predator–prey interactions.
The degree of adaptive phenotypic plasticity is correlated with the spatial environmental heterogeneity experienced by island populations of Rana temporaria
Authors: LIND M. I. , JOHANSSON F. 
Published: May 2007

AbstractAlthough theoretical models have identified environmental heterogeneity as a prerequisite for the evolution of adaptive plasticity, this relationship has not yet been demonstrated experimentally. Because of pool desiccation risk, adaptation of development rate is important for many amphibians. In a simulated pool‐drying experiment, we compared the development time and phenotypic plasticity in development time of populations of the common frog Rana temporaria, originating from 14 neighbouring islands off the coast of northern Sweden. Drying regime of pools used by frogs for breeding differed within and among the islands. We found that the degree of phenotypic plasticity in development time was positively correlated with the spatial variation in the pool‐drying regimes present on each island. In addition, local adaptation in development time to the mean drying rate of the pools on each island was found. Hence, our study demonstrates the connection between environmental heterogeneity and developmental plasticity at the island population level, and also highlights the importance of the interplay between local specialization and phenotypic plasticity depending on the local selection pressures.
Context‐dependent development of sexual ornamentation: implications for a trade‐off between current and future breeding efforts
Authors: BADYAEV A. V. , VLECK C. M. 
Published: May 2007

AbstractAllocation of resources into the development of sexual displays is determined by a trade‐off between the competing demands of current reproduction and self‐maintenance. When reproduction overlaps with acquisition of sexual ornamentation, such as in birds with a yearly post‐breeding moult, such a trade‐off can be expressed in elaboration of sexual traits used in subsequent matings. In turn, selection for elaboration of sexual ornaments should favour resolution of this trade‐off through a modification of the ornaments’ development, resulting in variable and life history‐dependent development of sexual displays. Here we examined a novel hypothesis that the trade‐off between current reproduction and development of sexual ornamentation in the house finch (Carpodacus mexicanus) can be mediated by the shared effects of prolactin – a pituitary hormone that regulates both parental care and moult in this species. We compared developmental variation in sexual ornamentation between breeding, nonbreeding, and juvenile males and examined the relative contribution of residual levels of prolactin and individual condition during moult to the acquisition of sexual ornamentation. Males that invested heavily in parental care entered post‐breeding moult in lower condition and later in the season, but their higher plasma prolactin was associated with shorter and more intense moult ultimately resulting in equal or greater elaboration of sexual ornamentation compared with nonparental males. Elaboration of sexual ornamentation of nonparental males that entered moult in greater condition, but with lower prolactin, was produced by longer and earlier moult and by lesser overlap in moult between sexual ornaments. Ornamentation of juvenile males that acquire sexual ornamentation for the first time was closely associated with physiological condition during moult. We discuss the implications of such context‐dependent ontogenies of sexual ornamentation and resulting differences in condition‐dependence of sexual traits across life history stages on the evolution of female preference for elaborated sexual displays.
QTL for popping characteristics in popcorn
Authors: Li Y. L. , Dong Y. B. , Niu S. Z. , Cui D. Q. 
Published: May 2007

AbstractPopping volume (PV), flake size (FS) and popping rate (PR) are three important popping characteristics in popcorn (Zea mays L.). We developed 259 F2:3 lines from a cross between a dent corn inbred ‘Dan232’ and a popcorn inbred ‘N04’ that were grown during spring and summer to evaluate the three popping characteristics. Fifteen quantitative trait loci (QTL) were detected on chromosomes 1, 2, 5, 6, 7 and 8 using composite interval mapping. The numbers of QTL were 6, 4 and 5 for PV, FS and PR, respectively, with phenotypic variance explained ranging from 4.9% to 15.6% for a single QTL, accounting for a total of 54.0%, 34.5% and 39.1% of the total phenotypic variance respectively. Partially dominance and overdominance effects played an important role in popping characteristics. Only 13 pairs of digenic interactions were detected. The QTL on chromosome bin 1.05–1.06 for PV and PR, and 5.07 for FS were in accordance with previous reports and could be good candidate QTL for marker‐assisted selection. There was a significant correlation amongst QTL on chromosomes 1, 6 and 8 for PV and PR.
Interspecific hybridization in the genusTrifolium
Authors: Abberton M. T. 
Published: May 2007

AbstractThe genusTrifolium(Leguminosae) or clovers includes a number of agriculturally important forage species. In particularTrifolium repens(white clover) andTrifolium pratense(red clover) are widely used in temperate livestock agriculture. Interspecific crossing programmes within this genus have been carried out for more than 50 years, in many cases involving embryo rescue or ovule culture techniques. In general, the aims of these have been twofold: to aid understanding of evolutionary relationships within the genus and to introgress useful traits, predominantly into white or red clover. In the case of white clover, the greatest efforts have been made with respect to crossing withTrifolium nigrescensandTrifolium ambiguum. Novel germplasm has been developed and useful traits transferred, although no material has yet been commercialized. The main emphasis with respect to red clover has been increasing longevity through crosses with more persistent species, particularlyTrifolium medium. Again, this work has not yet resulted in new varieties. Wider crossing programmes, allied in recent years to comparisons at the DNA level, have shed considerable light on the systematics and evolution of the genus. The future of interspecific hybridization for improvement of the agriculturally important clovers and the role of molecular approaches in this are discussed.