bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic and Epigenetic Alteration among Three Homoeologous Genes of a Class E MADS Box Gene in Hexaploid Wheat
Authors: Shitsukawa Naoki , Tahira Chikako , Kassai Ken-ichiro , Hirabayashi Chizuru , Shimizu Tomoaki , Takumi Shigeo , Mochida Keiichi , Kawaura Kanako , Ogihara Yasunari , Murai Koji
Published: June 2007

Bread wheat (Triticum aestivum) is a hexaploid species with A, B, and D ancestral genomes. Most bread wheat genes are present in the genome as triplicated homoeologous genes (homoeologs) derived from the ancestral species. Here, we report that both genetic and epigenetic alterations have occurred in the homoeologs of a wheat class E MADS box gene. Two class E genes are identified in wheat, wheat SEPALLATA (WSEP) and wheat LEAFY HULL STERILE1 (WLHS1), which are homologs of Os MADS45 and Os MADS1 in rice (Oryza sativa), respectively. The three wheat homoeologs of WSEP showed similar genomic structures and expression profiles. By contrast, the three homoeologs of WLHS1 showed genetic and epigenetic alterations. The A genome WLHS1 homoeolog (WLHS1-A) had a structural alteration that contained a large novel sequence in place of the K domain sequence. A yeast two-hybrid analysis and a transgenic experiment indicated that the WLHS1-A protein had no apparent function. The B and D genome homoeologs, WLHS1-B and WLHS1-D, respectively, had an intact MADS box gene structure, but WLHS1-B was predominantly silenced by cytosine methylation. Consequently, of the three WLHS1 homoeologs, only WLHS1-D functions in hexaploid wheat. This is a situation where three homoeologs are differentially regulated by genetic and epigenetic mechanisms.
Ubiquitin Lysine 63 Chain–Forming Ligases Regulate Apical Dominance inArabidopsis
Authors: Yin Xiao-Jun , Volk Sara , Ljung Karin , Mehlmer Norbert , Dolezal Karel , Ditengou Franck , Hanano Shigeru , Davis Seth J. , Schmelzer Elmon , Sandberg Göran , Teige Markus , Palme Klaus , Pickart Cecile , Bachmair Andreas
Published: June 2007

Lys-63–linked multiubiquitin chains play important roles in signal transduction in yeast and in mammals, but the functions for this type of chain in plants remain to be defined. The RING domain protein RGLG2 (for RING domain Ligase2) from Arabidopsis thaliana can be N-terminally myristoylated and localizes to the plasma membrane. It can form Lys-63–linked multiubiquitin chains in an in vitro reaction. RGLG2 has overlapping functions with its closest sequelog, RGLG1, and single mutants in either gene are inconspicuous. rglg1 rglg2 double mutant plants exhibit loss of apical dominance and altered phyllotaxy, two traits critically influenced by the plant hormone auxin. Auxin and cytokinin levels are changed, and the plants show a decreased response to exogenously added auxin. Changes in the abundance of PIN family auxin transport proteins and synthetic lethality with a mutation in the auxin transport regulator BIG suggest that the directional flow of auxin is modulated by RGLG activity. Modification of proteins by Lys-63–linked multiubiquitin chains is thus important for hormone-regulated, basic plant architecture.
Heat‐shock induction of T‐cell lymphoma/leukaemia in conditional Cre/lox‐regulated transgenic zebrafish
Authors: Feng Hui , Langenau David M. , Madge Jennifer A. , Quinkertz Andre , Gutierrez Alejandro , Neuberg Donna S. , Kanki John P. , Thomas Look A.
Published: June 2007

The zebrafish is an ideal vertebrate model system to investigate the complex genetic basis of cancer because it has the capacity for in vivo tumour‐cell imaging and forward genetic screens, and the molecular mechanisms regulating malignancy are remarkably conserved when compared with human. Our laboratory has previously generated transgenic zebrafish models that overexpress the mouse c‐Myc gene fused to enhanced green fluorescent protein (EGFP) and develop T‐cell acute lymphoblastic leukaemia (T‐ALL) that recapitulates the human disease both molecularly and pathologically. Our previous models have been limited by disease onset prior to sexual maturity and by the low disease penetrance when conditional transgenic embryos are injected with Cre RNA. Here, we report a novel system in which compound transgenic fish expressed both Cre controlled by the heat‐shock promoter and a rag2‐promoter‐regulated lox‐dsRED2‐lox‐EGFP‐mMyc cassette rag2‐LDL‐EMyc in developing T cells. After heat‐shock treatment at 3 d postfertilisation (dpf) for 45 min at 37°C, 81% of compound transgenic fish developed T‐lymphoblastic lymphoma (T‐LBL, mean latency 120 ± 43 (standard deviation) days of life), which rapidly progressed to T‐ALL. Heat‐shock‐regulated transgenic technology in zebrafish provides the missing link necessary to exploit the powerful genetic capacity of this organism to probe the multi‐step molecular pathogenesis of leukaemia.
Platelets release active matrix metalloproteinase‐2 in vivo in humans at a site of vascular injury: lack of inhibition by aspirin
Authors: Falcinelli Emanuela , Giannini Silvia , Boschetti Enrico , Gresele Paolo
Published: June 2007

When stimulated in vitro, human platelets release matrix metalloproteinase‐2 (MMP‐2) that, in turn, potentiates platelet activation. The present study investigated if MMP‐2 is released from activated platelets in vivo in humans and whether aspirin inhibits this release. MMP‐2 levels were measured by zymography, immunoblotting, flow‐cytometry and an activity assay system, in plasma prepared from blood emerging from a skin wound inflicted for the measurement of the bleeding time (shed blood) and simultaneously from venous blood in 27 healthy human volunteers. In a subgroup, the same measurements were carried out before and 1 h after aspirin intake. MMP‐2 was significantly higher in shed blood than in venous blood and increased progressively, consistent with ongoing platelet activation. A significant correlation was evident between platelet number and MMP‐2 in shed blood; platelet MMP‐2 content in shed blood was lower than that of platelets in venous blood. The level of active MMP‐2 released by activated platelets in vivo was within the range of concentrations that potentiate platelet activation. Aspirin did not reduce MMP‐2 release in vivo. In conclusion, MMP‐2 is released from platelets in vivo in humans at a localised site of vessel wall damage in amounts sufficient to potentiate platelet aggregation; aspirin does not reduce this release.
Biphenotypic acute leukaemia: a case series
Authors: Aribi Ahmed , Bueso‐Ramos Carlos , Estey Eli , Estrov Zeev , O'Brien Susan , Giles Francis , Faderl Stefan , Thomas Deborah , Kebriaei Partow , Garcia‐Manero Guillermo , Pierce Sherry , Cortes Jorge , Kantarjian Hagop , Ravandi Farhad
Published: June 2007

Biphenotypic acute leukaemia (BAL) is a rare type of leukaemia. Whether patients with BAL should be treated with regimens designed for acute myeloid leukaemia (AML), acute lymphocytic leukaemia (ALL) or both remain unclear.

We have reviewed the clinical data for 31 BAL patients. Most patients co‐expressed B‐lymphoid and myeloid markers. No specific chromosomal abnormality was identified. The majority of the patients were treated with regimens devised for treating ALL. Seven patients were treated with regimens designed for AML. Complete remission (CR) rates of 78% and 57% were noted respectively. The overall survival probability at 2 years was 60%.
Trisomy 19 is associated with trisomy 12 and mutated IGHV genes in B‐chronic lymphocytic leukaemia
Authors: Sellmann Ludger , Gesk Stefan , Walter Christoph , Ritgen Matthias , Harder Lana , Martín‐Subero José I. , Schroers Roland , Siemer Dörte , Nückel Holger , Dyer Martin J.S. , Dührsen Ulrich , Siebert Reiner , Dürig Jan , Küppers Ralf
Published: June 2007

The occurrence of trisomy 19 was investigated in 705 cases of B‐chronic lymphocytic leukaemia (CLL) by metaphase cytogenetic and/or fluorescence in situ hybridisation analyses. Trisomy 19 was detected in 11 cases (1·6%), all of which also carried a trisomy 12; nine of 10 had mutated IGHV genes. In contrast, B‐CLL cases with trisomy 12 lacking trisomy 19 mostly had unmutated IGHV genes. Karyotypes of the present study and the literature identified a strong correlation to trisomy 18 in addition to trisomy 12. Trisomy 19 seems to be a secondary event in B‐CLL with trisomy 12, mostly originating from mutated B cells.
Hepcidin, a key regulator of iron metabolism, is transcriptionally activated by p53
Authors: Weizer‐Stern Orly , Adamsky Konstantin , Margalit Ofer , Ashur‐Fabian Osnat , Givol David , Amariglio Ninette , Rechavi Gideon
Published: June 2007

Hepcidin is an iron‐regulatory protein that is upregulated in response to increased iron or inflammatory stimuli. Hepcidin reduces serum iron and induces iron sequestration in the reticuloendothelial macrophages – the hallmark of anaemia of inflammation. Iron deprivation is used as a defense mechanism against infection, and it also has a beneficial effect on the control of cancer. The tumour‐suppressor p53 transcriptionally regulates genes involved in growth arrest, apoptosis and DNA repair, and perturbation of p53 pathways is a hallmark of the majority of human cancers. This study inspected a role of p53 in the transcriptional regulation of hepcidin. Based on preliminary bioinformatics analysis, we identified a putative p53 response‐element (p53RE) contained in the hepcidin gene (HAMP) promoter. Chromatin immunoprecipitation (ChIP), reporter assays and a temperature sensitive p53 cell‐line system were used to demonstrate p53 binding and activation of the hepcidin promoter. p53 bound to hepcidin p53RE in vivo, andthis p53RE could confer p53‐dependent transcriptional activation. Activation of p53 increased hepcidin expression, while silencing of p53 resulted in decreased hepcidin expression in human hepatoma cells. Taken together, these results define HAMP as a novel transcriptional target of p53. We hypothesise that hepcidin upregulation by p53 is part of a defence mechanism against cancer, through iron deprivation. Hepcidin induction by p53 might be involved in the pathogenesis of anaemia accompanying cancer.
Incorporating bortezomib into upfront treatment for multiple myeloma: early results of total therapy 3
Authors: Barlogie Bart , Anaissie Elias , Van Rhee Frits , Haessler Jeffrey , Hollmig Klaus , Pineda‐Roman Mauricio , Cottler‐Fox Michele , Mohiuddin Abid , Alsayed Yazan , Tricot Guido , Bolejack Vanessa , Zangari Maurizio , Epstein Joshua , Petty Nathan , Steward Douglas , Jenkins Bonnie , Gurley Jennifer , Sullivan Ellen , Crowley John , Shaughnessy John D.
Published: June 2007

Total therapy 3 incorporated bortezomib into a melphalan‐based tandem transplant regimen for 303 newly diagnosed patients with myeloma. Induction chemotherapy prior to and consolidation chemotherapy after transplants each consisted of two cycles of VTD‐PACE (bortezomib, thalidomide, dexamethasone and 4‐d continuous infusions of cis‐platin, doxorubicin, cyclophosphamide, etoposide); 3‐year maintenance comprised monthly cycles of VTD in the first and TD in the remaining years. The median age was 59 years (age >64 years, 28%). A minimum of 20 × 106CD34 cells/kg was collected in 87% of patients; 83% completed both transplants, and only 5% suffered a treatment‐related death. At 24 months, 83% had achieved near‐complete remission, which was sustained in 88% at 2 years from its onset. With a median follow‐up of 20 months, 2‐year estimates of event‐free and overall survival were 84% and 86% respectively. The 44 patients who experienced an event more often had a high‐risk gene array profile, cytogenetic abnormalities and indicators of high lactate dehydrogenase, beta‐2‐microglobulin, creatinine and International Staging System stage. Toxicities of grade > 2 included thrombo‐embolic events in 27% and peripheral neuropathy in 12%. Results of this phase‐2 study demonstrated that bortezomib could be safely combined with multi‐agent chemotherapy, effecting near‐complete remission status and 2‐year survival rates in more than 80% of patients.
Molecular analysis of the human thrombin‐activatable fibrinolysis inhibitor gene promoter
Authors: Garand Mathieu , Bastajian Nazareth , Nesheim Michael E. , Boffa Michael B. , Koschinsky Marlys L.
Published: June 2007

Thrombin‐activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B‐like pro‐enzyme that, once activated, attenuates fibrinolysis. Little is presently known of the factors that regulate expression of CPB2, the gene encoding TAFI. This study identified 10 potential transcription factor binding sites (denoted A–J) within the proximal promoter region of CPB2, spanning nucleotides −425 to +21; two of these represent previously‐described binding sites for CCAAT/enhancer binding protein and glucocorticoid receptor. We identified additional transcription factors that bind within the proximal CPB2 promoter, namely, nuclear factor‐Y (NF‐Y) and hepatocyte nuclear factor‐1α (HNF‐1α). Binding of NF‐Y to the region between nucleotides −76 to −59 (Site B) is important for basal CPB2 promoter activity; NF‐Y may be a key factor for the recruitment of the transcriptional machinery to the TAFI gene promoter. HNF‐1α binds at the interface between Sites C and B. Transient transfections of CPB2 promoter‐reporter constructs showed that HNF‐1α binding is essential for the activity of this promoter in HepG2 cells, indicating that HNF‐1α is involved in the liver‐specific expression of CPB2.
A strategic framework for novel drug development in multiple myeloma
Authors: Anderson Kenneth C. , Hannah Alison L. , Pazdur Richard , Farrell Ann T.
Published: June 2007

Although multiple myeloma remains incurable, recent advances in research have created a new paradigm for the development of novel agents for myeloma treatment. Biological insights are being translated rapidly from bench to bedside, with an increasing number of agents available at all stages of disease. Concomitantly, the drug development and approval process has become more challenging. Defining optimal clinical dosing schedules and therapeutic regimens is increasingly dependent on insights derived from genomic, proteomic and cell signaling studies. Because the maximum tolerated dose of a novel agent may not be the same as the optimal biological dose, designing phase I trials is more complex. Evaluation of new agents in patients who have relapsed is more challenging because the number of effective therapies has increased. Finally, choosing a ‘standard therapy’ control arm for randomised trials is more difficult because of the increased number of potential comparator regimens. In June 2005, the Multiple Myeloma Research Foundation (MMRF) sponsored a roundtable symposium in Washington, DC, to define the strategies and guidelines for phases I, II and III development of new myeloma agents, with the ultimate goal of speeding delivery of new therapies to myeloma patients.
The linear effects of α‐thalassaemia, the UGT1A1 and HMOX1 polymorphisms on cholelithiasis in sickle cell disease
Authors: Vasavda Nisha , Menzel Stephan , Kondaveeti Sheila , Maytham Emma , Awogbade Moji , Bannister Sybil , Cunningham Juliette , Eichholz Andrew , Daniel Yvonne , Okpala Iheanyi , Fulford Tony , Thein Swee Lay
Published: June 2007

Serum bilirubin levels and predisposition to gallstones in sickle cell disease (SCD) are influenced by genetic variation in the hepatic uridine diphosphate (UDP)‐glucuronosyltransferase (UGT1A1) gene, but the association is not consistent. This study investigated whether variation in the gene encoding haem oxygenase (HMOX1), a rate‐limiting enzyme upstream of UGT1A in the haem catabolic pathway, and α‐thalassaemia could explain some of the inconsistent effects. The UGT1A1 [TA]n and HMOX1 [GT]n promoter polymorphisms and α globin genotypes were determined in 263 SCD patients (199 HbSS, 5 HbS/β0, 59 HbSC). Detection of gallstones was based on ultrasound of the liver/biliary tree. Regression analysis showed that serum bilirubin levels and the incidence of gallstones were strongly associated with the number of UGT1A1 [TA] repeats in all subjects (P < 0·0001 and P < 0·01, respectively). While HMOX1 genotype had no effect, co‐inheritance of α‐thalassaemia reduced serum bilirubin levels in all SCD patients independently of the number of UGT1A1 [TA] repeats. Each additional [TA] repeat is associated with an increase in mean serum bilirubin levels of 21% and cholelithiasis risk of 87% in SCD.
Characterisation of genomic translocation breakpoints and identification of an alternative TCF3/PBX1 fusion transcript in t(1;19)(q23;p13)‐positive acute lymphoblastic leukaemias
Authors: Paulsson Kajsa , Jonson Tord , Øra Ingrid , Olofsson Tor , Panagopoulos Ioannis , Johansson Bertil
Published: June 2007

The t(1;19)(q23;p13), one of the most common translocations in childhood and adult acute lymphoblastic leukaemias (ALLs), usually results in fusion of exons 1–16 of TCF3 (previously E2A) and exons 3–9 of PBX1. However, some t(1;19)‐positive ALLs are negative for this chimaera. We here report an alternative TCF3/PBX1 transcript, fusing exon 17 of TCF3 with exon 5 of PBX1, in a paediatric t(1;19)‐positive ALL. The different breakpoints made this hybrid undetectable by reverse transcription polymerase chain reaction using standard TCF3 and PBX1 primers. Hence, ALLs with t(1;19) that test negative for TCF3/PBX1 should be analysed further before excluding this alternative fusion. Furthermore, we have characterised the genomic translocation breakpoints in eight TCF3/PBX1‐positive ALLs; four cases with a balanced t(1;19) and four with an unbalanced der(19)t(1;19). It has previously been suggested that the breakpoints are clustered, particularly in TCF3, and that N‐nucleotides are frequently present in the fusion junctions. Three of seven investigated TCF3 intron 16 breakpoints were within the previously described 14 base pair‐cluster, and all but two junctions harboured N‐nucleotides. The PBX1 breakpoints were more dispersed, although still clustered in two regions. This confirms that most t(1;19) rearrangements may arise by a combination of illegitimate V(D)J recombination and non‐homologous end joining.
Adding low‐dose gemtuzumab ozogamicin to fludarabine, Ara‐C and idarubicin (MY‐FLAI) may improve disease‐free and overall survival in elderly patients with non‐M3 acute myeloid leukaemia: results of a prospective, pilot, multi‐centre trial and comparison with a historical cohort of patients
Authors: Clavio Marino , Vignolo Luana , Albarello Alessandra , Varaldo Riccardo , Pierri Ivana , Catania Gioacchino , Balocco Manuela , Michelis Gianluca , Miglino Maurizio , Manna Annunziata , Balleari Enrico , Carella A. Michele , Sessarego Mario , Van Lint Maria Teresa , Bacigalupo Andrea , Gobbi Marco
Published: June 2007

We report the final results of a prospective multi‐centre trial testing the combination of chemotherapy (fludarabine, cytosine arabinoside and idarubicin; FLAI) followed by low‐dose gemtuzumab ozogamicin (GO), for induction treatment of patients with CD33+ acute myeloid leukaemia (AML). Forty‐six consecutive patients were treated: the median age was 66 (range: 60–80) years; the karyotype was unfavourable in 12 patients (26%), intermediate in 33 (71%) and favourable in one (3%). Eleven major infectious complications were recorded. There was one early death. Of the 45 evaluable patients, 24 achieved a complete response (CR; 52%), 66% and 33% in good‐intermediate/poor karyotype patients. Median duration of CR was 7 (3–24) months. The cumulative incidence of relapse was 37% with an actuarial 2‐year survival of 54%. These results were compared with 47 patients matched for age and karyotype who received FLAI, without GO. The proportion of patients achieving CR was comparable. However, patients with de novo AML receiving GO (n = 26) had a significantly lower risk of relapse at 2 years when compared with patients not receiving GO (n = 35) (40% vs. 80%, P = 0·01) and significantly better overall 2‐year survival (40% vs. 14%P = 0·02). Patients with secondary AML had comparable outcome whether or not they received GO. This GO‐based induction chemotherapy has a good toxicity profile. In keeping with a recent prospective randomised trial, the addition of GO seems to prolong disease‐free survival.
Expression of functional soluble human leucocyte antigen‐G molecules in lymphoproliferative disorders
Authors: Sebti Yasmine , Le Maux Amélie , Gros Frédéric , De Guibert Sophie , Pangault Céline , Rouas‐Freiss Nathalie , Bernard Marc , Amiot Laurence
Published: June 2007

Membrane‐bound and soluble human leucocyte antigen‐G (sHLA‐G) molecules display immunotolerant properties favouring tumour cell escape from immune surveillance. sHLA‐G molecules have been detected in several tumour pathologies; this study aimed to evaluate sHLA‐G expression in lymphoproliferative disorders. sHLA‐G plasma level was significantly increased in 110 of 178 newly diagnosed lymphoid proliferations cases i.e. 59% of chronic lymphocytic leukaemia, 65% of B non‐Hodgkin lymphomas (NHL) and 58% of T‐NHL. To assess the mechanisms involved in this secretion, the differential effect of cytokines was tested in in vitro cultures of NHL cells. A significant induction of sHLA‐G level was shown in T‐NHL in contrast with B‐NHL and normal equivalent cells, after cytokine stimulation with (i) interferonγ (IFNγ), interleukin‐2 (IL‐2) and granulocyte‐macrophage colony‐stimulating factor, (ii) IL‐10 and (iii) transforming growth factor β. An impact of microenvironment on sHLA‐G expression was found in B‐NHL as shown by the in vitro effect of addition of normal monocytes. Finally, a functional effect of sHLA‐G molecules purified from pathologic plasma was demonstrated by their strong capacity to inhibit T‐cell proliferation at concentrations currently observed during these disorders. These results suggest that functional sHLA‐G molecules are upregulated in lymphoproliferative disorders which can support their potential immunomodulatory role during this pathology.
The management and outcome of chronic graft‐versus‐host disease
Authors: Fraser Christopher J. , Scott Baker K.
Published: June 2007

Chronic graft‐versus‐host disease (cGVHD) is a common complication following allogeneic haematopoietic cell transplantation (HCT). It is the leading cause of non‐relapse mortality in transplant survivors and has a significant impact upon their functional status and quality of life. Despite significant advances being made in the field of HCT over the past 25 years, there has been little change in the incidence, morbidity and mortality of cGVHD. This is partly because of a lack of understanding about the pathogenesis of the disorder but also because a lack of well validated grading systems and outcome measures has hindered clinical research. Strategies for prophylaxis have largely been unsuccessful and may compromise the graft‐versus‐leukaemia (GVL) effect. Standard primary treatment remains a combination of corticosteroids and calcineurin inhibitors. There is no standard therapy for those who fail to respond to corticosteroids. Many agents have been studied but there is an urgent need for systematic research to compare the efficacy of different approaches. Infection is the leading cause of death among patients with cGVHD so antimicrobial prophylaxis is mandatory. A multidisciplinary approach to the care of patients with cGVHD is essential to adequately address its effects on both physical and psychological functioning.
Review of the value of colony stimulating factors for prophylaxis of febrile neutropenic episodes in adult patients treated for haematological malignancies
Authors: Levenga Tjakiena Henriette , Timmer‐Bonte Johanna N. H.
Published: June 2007

Chemotherapy‐induced neutropenia is a major dose‐limiting toxicity of systemic cancer chemotherapy that can lead to fever and infection, requiring prompt analysis and in‐patient treatment with broad‐spectrum antibiotics. Complicated neutropenia may lead to reduction and/or delay of systemic anti‐cancer treatment, which may compromise outcome. Haematopoietic growth factors have the ability to augment haematopoietic cell cycling and are used to facilitate more dose‐intense treatments and to decrease treatment‐related complications. This review focuses on randomised trials that investigated the use of colony‐stimulating factors (CSF) to prevent treatment‐related febrile complications in haematological malignancies in (younger) adult patients. In general, these studies demonstrated that CSF reduced the duration of severe neutropenia but not always its febrile complications; therefore inconsistent results regarding clinically relevant reduction of hospitalisation, duration of therapeutic antibiotics, infection‐related or disease‐related mortality and economic effects were reported. Current developments in treatment of haematological malignancies will pose new challenges as a shift in infectious pathogens can be expected.
Antimyeloma effects of arsenic trioxide are enhanced by melphalan, bortezomib and ascorbic acid
Authors: Campbell Richard A. , Sanchez Eric , Steinberg Jeffrey A. , Baritaki Stavroula , Gordon Melinda , Wang Cathy , Shalitin Dror , Chen Haiming , Pang Shen , Bonavida Benjamin , Said Jonathan , Berenson James R.
Published: June 2007

Arsenic trioxide (ATO) induces apoptosis of malignant plasma cells through multiple mechanisms, including inhibition of DNA binding by nuclear factor kappa‐B, a key player in the development of chemoresistance in multiple myeloma (MM). This activity suggests that ATO may be synergistic when combined with other active antimyeloma drugs. To evaluate this, we examined the antimyeloma effects of ATO alone and in combination with bortezomib, melphalan and ascorbic acid (AA) both in vitro and in vivo using a severe combined immunodeficient (SCID)‐hu murine myeloma model. Marked synergistic antimyeloma effects were demonstrated when human MM Los Angeles xenograft IgG lambda light chain (LAGλ‐1) cells were treated in vitro with ATO and any one of these agents. SCID mice bearing human MM LAGλ‐1 tumours were treated with single‐agent ATO, bortezomib, melphalan, or AA, or combinations of ATO with either bortezomib or melphalan and AA. Animals treated with any of these drugs alone showed tumour growth and increases in paraprotein levels similar to control mice, whereas animals treated with ATO‐containing combinations showed markedly suppressed tumour growth and significantly reduced serum paraprotein levels. These in vitro and in vivo results suggest that addition of ATO to other antimyeloma agents may result in improved outcomes for patients with relapsed or refractory MM.
The effect of dispersal ability in winter and summer stoneflies on their genetic differentiation
Authors: YASICK ALISON L. , KREBS ROBERT A. , WOLIN JULIE A.
Published: June 2007

Abstract 1. Plecopteran species disperse less than most other aquatic insects. Within stoneflies, members of different families vary in the degree of wing morphology and season of adult emergence.

2. Dispersal limitations were tested to determine if there were increased differences among the nearby, Chagrin and Grand River populations in north‐eastern Ohio, by comparing genetic variation within the 16s rRNA region of mitochondrial DNA in two stoneflies. Allocapnia recta emerges in winter and often has rudimentary wings, and Leuctra tenuis emerges in summer with fully developed wings.

3. There was significant genetic variability between the samples of A. recta from two adjacent rivers (FST = 0.20), but not between samples of L. tenuis (FST = 0.07).

4. Distinct clades in A. recta were found to occur within the minimum spanning tree specific to the Chagrin River, which contributed to a significant difference in gene diversity between the two rivers. Haplotypes in L. tenuis appeared randomly distributed between the two rivers; however, nucleotide diversity was significantly less in samples from the Grand River.

5. Shared haplotypes of both species illustrate the inter‐connectedness of the Chagrin and Grand River populations, and the lower genetic variability of L. tenuis between the two rivers is indicative of its greater dispersal capability.
Predation risk perception and food scarcity induce alterations of life‐cycle traits of the mosquito Culex pipiens
Authors: BEKETOV MIKHAIL A. , LIESS MATTHIAS
Published: June 2007

Abstract 1. Predators may affect prey populations by direct consumption, and by inducing defensive reactions of prey to the predation risk. Food scarcity frequently has effects on the inducible defences of prey, but no consistent pattern of food–predation risk interaction is known.

2. In this study the combined effect of food shortage and predation‐risk perception in larvae of the mosquito Culex pipiens was investigated. Water exposed to the aquatic predator bug Notonecta glauca was used as a source of predation intimidation. Mosquito larvae were reared in three different media containing either no predator cues or the cues of N. glauca that had been fed on either C. pipiens larvae or on Daphnia magna. Food was provided in favourable or limited amount for these set‐ups.

3. The results showed that chemical cues from the predators fed with prey’s conspecifics caused a decreased survival, delayed pre‐imaginal development, and reduction in body size of emerged mosquitoes, whereas chemical cues from predators fed with D. magna caused only delayed development. Food scarcity significantly exacerbates the negative effect of the predator cues on pre‐imaginal development of C. pipiens. Effects of the cues on larval development and body size of imagoes are significantly stronger for females than for males.

4. The present study suggests that when food is limited, predators can affect population dynamics of prey not only by direct predation, but also by inducing lethal and sublethal effects due to perception of risk imposed by chemical cues. To understand the effects of predators on mosquito population dynamics, environmental parameters such as food deficiency should be considered.
Increasing tolerance to Cry1Ac cotton from cotton bollworm, Helicoverpa armigera, was confirmed in Bt cotton farming area of China
Authors: LI GUO‐PING , WU KONG‐MING , GOULD FRED , WANG JIAN‐KANG , MIAO JIN , GAO XI‐WU , GUO YU‐YUAN
Published: June 2007

Abstract 1. Changes in the frequency of Cry1Ac resistance genes and shifts in tolerance of cotton bollworm, Helicoverpa armigera, to the Cry1Ac toxin were assessed using bioassays of F1 and F2 offspring of isofemale lines from Anci County of Hebei Province (a multiple‐crop system including corn, soybean, peanut, and Bt cotton) and Xiajin County of Shandong Province (an intensive Bt cotton planting area) in Northern China during 2002–2005.

2. A conservative analysis of the overall results indicated that there was a small increase in the frequency of major, non‐recessive resistance genes over time.

3. The relative average development ratings [RADR – growth rate of a line on a Bt diet in proportion to the growth rate on a non‐Bt (NBT) diet] of the bollworm larvae in F1 tests increased significantly from year to year, indicating a gradual trend towards higher tolerance to Cry1Ac in the field populations.

4. There were also significant positive correlations between RADR of the lines in the F1 generation and the RADR of their F2 offspring, indicating that the tolerance was genetically based.

5. Quantitative genetic simulation analysis showed that resistance of H. armigera to Bt cotton in Xiajin could evolve to a high level in 11–15 years if no effective resistance management measures are carried out.
Factors influencing nitrogen and phosphorus excretion rates of fish in a shallow lake
Authors: VERANT MICHELLE L. , KONSTI MELISSA L. , ZIMMER KYLE D. , DEANS CARRIE A.
Published: June 2007

Summary 1. Fish excretion can be an important source of nutrients in aquatic ecosystems. Nitrogen (N) and phosphorus (P) excretion rates are influenced by many factors, including fish diet, fish growth rate and fish size. However, the relative influence of these and other factors on community‐level excretion rates of fish is unknown.

2. We used bioenergetics modeling to estimate excretion rates of eight fish species in a shallow, Minnesota (U.S.A.) lake over four months in both 2004 and 2005. Excretion rates of each species were summed for community‐level N and P excretion rates, as well as the N : P ratio of excretion. We then used a model‐selection approach to assess ability of independent variables to predict excretion rates, and to identify the most parsimonious model for predicting N : P excretion ratios and P and N excretion rates at the community scale. Predictive models were comprised of the independent variables water temperature and average fish density, fish size, fish growth rate, nutrient content of fish and nutrient content of fish diets at the community scale.

3. Fish density and nutrient content of fish diets (either N or P) were the most parsimonious models for predicting both N and P excretion rates, and explained 96% and 92% of the variance in N and P excretion, respectively. Moreover, fish density and nutrient models had 1400‐fold more support for predicting N and 21‐fold more support for predicting P excretion relative to models based on fish density only. Water temperature, fish size, fish growth rates and nutrient content of fish showed little influence on excretion rates, and none of our independent variables showed a strong relationship with N : P ratios of excretion.

4. Past work has focused on the importance of fish density as a driver of fish excretion rates on a volumetric basis. However, our results indicate that volumetric excretion rates at the community scale will also change substantially in response to changes in relative abundance of fish prey or shifts in relative dominance of planktivores, benthivores, or piscivores. Changes in community‐scale excretion rates will have subsequent influences on algal abundance, water clarity, and other ecosystem characteristics.
The effect of supplementary winter seed food on breeding populations of farmland birds: evidence from two large‐scale experiments
Authors: SIRIWARDENA GAVIN M. , STEVENS DANAË K. , ANDERSON GUY Q. A. , VICKERY JULIET A. , CALBRADE NEIL A. , DODD STEPHEN
Published: June 2007

Low winter food availability is probably critical in the declines of many farmland bird species in Europe, leading to the implementation of ameliorative agri‐environment scheme options. To date, however, there has been no experimental test of the effectiveness of such options.

We report the results of two large‐scale, 3‐year, controlled experiments investigating the effects of supplementary winter seed provision on breeding farmland bird abundance. In each experiment, the use of winter feeding sites by birds was monitored and the availability of alternative, seed‐rich habitat in the surrounding area was measured. The Winter Food for Birds (WFFB) project also included variable levels of food provision. Breeding bird abundance was then monitored in experimental and control areas. The Bird Aid project targeted yellowhammer Emberiza citrinella L., corn bunting Emberiza calandra L. and tree sparrow Passer montanus L., while WFFB considered 11 species that used supplementary winter food.

Comparisons of trends in breeding abundance between experimental and control areas revealed little evidence for positive effects of feeding, but there was great variation in the use of feeding sites by each species, and therefore in the seed quantity birds received.

Declines for yellowhammer, robin and dunnock were less steep where more food was provided in WFFB areas (a fourfold difference in seed provision across 1·5 times the land area).

Analysing trends with respect to weight‐of‐use of winter food revealed significant, positive relationships for yellowhammer (both projects) and up to five other species, depending on the control terms applied. Thus, positive effects of feeding on population change depend on the effective supply of seed to the species of interest. The hypothesis that winter food is currently limiting the populations concerned is also supported.

Synthesis and applications. Effective winter food provision to farmland bird populations has the potential to halt, and perhaps to reverse, declines in abundance. In practice, this means that agri‐environment measures supplying significant quantities of winter food, such as stubbles preceded by low‐input cereals, should succeed in changing population trends if they provide resources at the times of greatest need and if there is sufficient uptake.
Co(i)‐ordinating defenses: NaCOI1 mediates herbivore‐ induced resistance in Nicotiana attenuata and reveals the role of herbivore movement in avoiding defenses
Authors: Paschold Anja , Halitschke Rayko , Baldwin Ian T.
Published: June 2007

Arabidopsis and tomato plants mutated in the F‐box protein COI1 mediating jasmonate (JA) responses are more susceptible to herbivores in laboratory trials, but the exact mechanisms of COI1‐mediated resistance are not known. We silenced COI1 by transformation with an inverted repeat construct (ir‐coi1) in Nicotiana  attenuata, a plant the direct and indirect defenses of which against various herbivores have been well studied. ir‐coi1 plants are male sterile and impaired in JA‐elicited direct [nicotine, caffeoylputrescine and trypsin proteinase inhibitor (TPI) activity] and indirect (cis‐α‐bergamotene emission) defense responses; responses not elicited by JA treatment (ethylene production and flower TPI activity) were unaffected. Larvae of Manduca  sexta, a common herbivore of N. attenuata, gained three times more mass feeding on ir‐coi1 than on wild‐type (WT) plants in glasshouse experiments. By regularly moving caterpillars to unattacked leaves of the same plant, we demonstrate that larvae on WT plants can grow and consume leaves as fast as those on ir‐coi1 plants, a result that underscores the role of COI1 in mediating locally induced resistance in attacked leaves, and the importance of herbivore movement in avoiding the induced defenses of a plant. When transplanted into native habitats in the Great Basin Desert, ir‐coi1 plants suffer greatly from damage by the local herbivore community, which includes herbivores not commonly found on N. attenuata WT plants. Choice assays with field‐grown plants confirmed the increased attractiveness of ir‐coi1 plants for both common and unusual herbivores. We conclude that NaCOI1 is essential for induced resistance in N. attenuata, and that ir‐coi1 plants highlight the benefits of herbivore movement for avoiding induced defenses.
RING‐H2 type ubiquitin ligase EL5 is involved in root development through the maintenance of cell viability in rice
Authors: Koiwai Hanae , Tagiri Akemi , Katoh Shizue , Katoh Etsuko , Ichikawa Hiroaki , Minami Eiichi , Nishizawa Yoko
Published: June 2007

Rice EL5 is an ATL family gene characterized by a transmembrane domain at the N‐terminal and a RING‐H2 finger domain (RFD), which exhibits ubiquitin ligase (E3) activity. To elucidate the physiological roles of EL5, we analyzed transgenic rice plants overexpressing mutant EL5 proteins that are impaired in E3 activity to various degrees. Plants expressing EL5C153A and EL5W165A, which encode an inactive E3, showed a rootless phenotype accompanied by cell death in root primordia, and those expressing EL5V162A, with moderately impaired E3 activity, formed short crown roots with necrotic lateral roots. The dominant‐negative phenotype was specifically observed in root meristems where EL5 is expressed, and not recovered by exogenous auxin. When wild‐type EL5 was transcriptionally overexpressed, the EL5 protein was barely detected by Western blotting. Neither treatment with a proteasome inhibitor nor mutation of the sole lysine residue, a potential target of ubiquitination, resulted in increased EL5 accumulation, whereas mutations in the RFD led to increased EL5 accumulation. The stabilized EL5 without the RFD was localized in the plasma membrane. Deletion of the transmembrane domain prevented the EL5 from localizing in the membrane and from exerting an inhibitory effect on root formation. Deletion of the C‐terminal region also neutralized the negative effect. We concluded that EL5 plays a major role as a membrane‐anchored E3 for the maintenance of cell viability after the initiation of root primordial formation. In addition, we propose that EL5 is an unstable protein, of which degradation is regulated by the RFD in a proteasome‐independent manner.
Identification and characterization of pin and thrum alleles of two genes that co‐segregate with the Primula S locus
Authors: Li Jinhong , Webster Margaret , Furuya Masaki , Gilmartin Philip M.
Published: June 2007

The study of heteromorphy in Primula over the past 140 years has established the reproductive significance of this breeding system. Plants produce either thrum or pin flowers that demonstrate reciprocal herkogamy. Thrums have short styles and produce large pollen from anthers at the mouth of the flower; pins have long styles and produce small pollen from anthers located within the corolla tube. The control of heteromorphy is orchestrated by the S locus with dominant (S) and recessive (s) alleles that comprise a co‐adapted linkage group of genes. Thrum plants are heterozygous (Ss) and pin plants are homozygous (ss). Reciprocal crosses between the two forms are required for fertilization; within‐morph crosses are impeded by a sporophytic self‐incompatibility system. Rare recombination events within the S locus produce self‐fertile homostyles. As a first step towards identifying genes located at the S locus, we used fluorescent differential display to screen for differential gene expression in pin and thrum flowers. Rather than only detecting differentially regulated genes, we identified two S locus linked genes by virtue of allelic variation between pin and thrum transcripts. Analysis of pin and thrum plants together with homostyle recombinant reveals that one gene flanks the locus, whereas the other shows complete linkage. One gene is related to Arabidopsis flower‐timing genes Col9 and Col10; the other encodes a small predicted membrane protein of unknown function. Notwithstanding the diallelic behaviour of the Primula S locus, analysis of pin and thrum plants reveal three alleles for each gene: two pin and one thrum.
A Pseudomonas syringae pv. tomato DC3000 mutant lacking the type III effector HopQ1‐1 is able to cause disease in the model plant Nicotiana benthamiana
Authors: Wei Chia‐Fong , Kvitko Brian H. , Shimizu Rena , Crabill Emerson , Alfano James R. , Lin Nai‐Chun , Martin Gregory B. , Huang Hsiou‐Chen , Collmer Alan
Published: June 2007

The model pathogen Pseudomonas syringae pv. tomato DC3000 causes bacterial speck in tomato and Arabidopsis, but Nicotiana benthamiana, an important model plant, is considered to be a non‐host. Strain DC3000 injects approximately 28 effector proteins into plant cells via the type III secretion system (T3SS). These proteins were individually delivered into N. benthamiana leaf cells via T3SS‐proficient Pseudomonas fluorescens, and eight, including HopQ1‐1, showed some capacity to cause cell death in this test. Four gene clusters encoding 13 effectors were deleted from DC3000: cluster II (hopH1, hopC1), IV (hopD1, hopQ1‐1, hopR1), IX (hopAA1‐2, hopV1, hopAO1, hopG1), and native plasmid pDC3000A (hopAM1‐2, hopX1, hopO1‐1, hopT1‐1). DC3000 mutants deleted for cluster IV or just hopQ1‐1 acquired the ability to grow to high levels and produce bacterial speck lesions in N. benthamiana. HopQ1‐1 showed other hallmarks of an avirulence determinant in N. benthamiana: expression in the tobacco wildfire pathogen P. syringae pv. tabaci 11528 rendered this strain avirulent in N. benthamiana, and elicitation of the hypersensitive response in N. benthamiana by HopQ1‐1 was dependent on SGT1. DC3000 polymutants involving other effector gene clusters in a hopQ1‐1‐deficient background revealed that clusters II and IX contributed to the severity of lesion symptoms in N. benthamiana, as well as in Arabidopsis and tomato. The results support the hypothesis that the host ranges of P. syringae pathovars are limited by the complex interactions of effector repertoires with plant anti‐effector surveillance systems, and they demonstrate that N. benthamiana can be a useful model host for DC3000.
Nicotinamidase activity is important for germination
Authors: Hunt Lee , Holdsworth Michael J. , Gray Julie E.
Published: June 2007

It has been suggested that nicotinamide must be degraded during germination; however, the enzyme responsible and its physiological role have not been previously studied. We have identified an Arabidopsis gene, NIC2, that is expressed at relatively high levels in mature seed, and encodes a nicotinamidase enzyme with homology to yeast and bacterial nicotinamidases. Seed of a knockout mutant, nic2‐1, had reduced nicotinamidase activity, retarded germination and impaired germination potential. nic2‐1 germination was restored by after‐ripening or moist chilling, but remained hypersensitive to application of nicotinamide or ABA. Nicotinamide is a known inhibitor of NAD‐degrading poly(ADP‐ribose) polymerases (PARP enzymes) that are implicated in DNA repair. We found reduced poly(ADP)ribosylation levels in nic2‐1 seed, which were restored by moist chilling. Furthermore, nic2‐1 seed had elevated levels of NAD, and germination was hypersensitive to methyl methanesulphonate (MMS), suggesting that PARP activity and DNA repair responses were impaired. We suggest that nicotinamide is normally metabolized by NIC2 during moist chilling or after‐ripening, which relieves inhibition of PARP activity and allows DNA repair to occur prior to germination.
The cell cycle‐associated protein kinase WEE1 regulates cell size in relation to endoreduplication in developing tomato fruit
Authors: Gonzalez Nathalie , Gévaudant Frédéric , Hernould Michel , Chevalier Christian , Mouras Armand
Published: June 2007

Tomato fruit size results from the combination of cell number and cell size which are respectively determined by cell division and cell expansion processes. As fruit growth is mainly sustained by cell expansion, the development of pericarp and locular tissues is characterized by the concomitant arrest of mitotic activity, inhibition of cyclin‐dependent kinase (CDK) activity, and numerous rounds of endoreduplication inducing a spectacular increase in DNA ploidy and mean cell size. To decipher the molecular basis of the endoreduplication‐associated cell growth in fruit, we investigated the putative involvement of the WEE1 kinase (Solly;WEE1). We here report a functional analysis of Solly;WEE1 in tomato. Impairing the expression of Solly;WEE1 in transgenic tomato plants resulted in a reduction of plant size and fruit size. In the most altered phenotypes, fruits displayed a reduced number of seeds without embryo development. The reduction of plant‐, fruit‐ and seed size originated from a reduction in cell size which could be correlated with a decrease of the DNA ploidy levels. At the molecular level downregulating Solly;WEE1 in planta resulted in the increase of CDKA activity levels originating from a decrease of the amount of Y15‐phosphorylated CDKA, thus indicating a release of the negative regulation on CDK activity exerted by WEE1. Our data indicated that Solly;WEE1 participates in the control of cell size and/or the onset of the endoreduplication process putatively driving cell expansion.