Microsatellite loci and peroxidase alleles correlation in somaclonal variation of Eucalyptus microtheca F. Muell

The aim of this study was to investigate the correlation between biochemical and molecular markers in Eucalyptus microtheca F. Muell. under in vitro culture. For this mean, twig-derived explants obtainedfrom Eucalyptus microtheca 1-year-old seedling were cultured on modified MS medium, supplemented with different concentrations of NAA, Kin and TDZ. POD (peroxidase) alleles patterns were studied among regenerated plantlets to investigate the effect of TDZ concentration on POD activity. A dimer locus, a tetramer locus and two epigenetic bands were observed. Genome variation among somaclonal plantlets were investigated using microsatellite markers. SSR (Simple Sequence Repeat) markers revealed polymorphism among the studied population. Nonparametric statistical analysis showed significant effect of simple sequence repeats loci on peroxidase alleles. Correlation of two similarity matrix POD and SSRs loci was 0.18 using Mental test. Results showed less stability of dimer locus indifferent concentrations of TDZ compared to tetramer locus. Tetramer alleles showed more correlation to SSRs than that of dimmer ones

The effect of plant growth regulators, explants and cultivars on spinach (Spinacia oleracea L.) tissue culture

Spinach (Spinacia oleracea L.) is an important vegetable crop of which dioecy in nature has made cultivar improvement difficult using traditional breeding methods; therefore, production of high amount of disease free spinach is critical. To achieve the best explants and media for spinach tissue culture, the effects of two different plant growth regulators, two explants and cultivars on adventitious shoot regeneration were tested. The Analysis of Variance (ANOVA) showed that the effects of plant growth regulators on spinach tissue culture were significant; moreover, the effects of explants were not significant except on the regeneration phase. The best medium for callous induction was MS media containing 1.5 mgl-1 IAA + 2.5 mgl-1 GA3. The best medium for shoot regeneration was MS media contained 0.5 mgl-1 NAA + 2 mgl-1 GA3. The best rooting medium was MS medium containing 0.5 mgl-1 IBA. Results presented inhibitory effect of GA3 for callus and root formation; whereas, promote shoot development

Candidate Genes for Expansion and Transformation of Hematopoietic Stem Cells by NUP98-HOX Fusion Genes

BACKGROUND: Hox genes are implicated in hematopoietic stem cell (HSC) regulation as well as in leukemia development through translocation with the nucleoporin gene NUP98. Interestingly, an engineered NUP98-HOXA10 (NA10) fusion can induce a several hundred-fold expansion of HSCs in vitro and NA10 and the AML-associated fusion gene NUP98-HOXD13 (ND13) have a virtually indistinguishable ability to transform myeloid progenitor cells in vitro and to induce leukemia in collaboration with MEIS1 in vivo. METHODOLOGY/PRINCIPAL FINDINGS: These findings provided a potentially powerful approach to identify key pathways mediating Hox-induced expansion and transformation of HSCs by identifying gene expression changes commonly induced by ND13 and NA10 but not by a NUP98-Hox fusion with a non-DNA binding homedomain mutation (N51S). The gene expression repertoire of purified murine bone marrow Sca-1+Lin- cells transduced with retroviral vectors encoding for these genes was established using the Affymetrix GeneChip MOE430A. Approximately seventy genes were differentially expressed in ND13 and NA10 cells that were significantly changed by both compared to the ND13(N51S) mutant. Intriguingly, several of these potential Hox target genes have been implicated in HSC expansion and self-renewal, including the tyrosine kinase receptor Flt3, the prion protein, Prnp, hepatic leukemia factor, Hlf and Jagged-2, Jag2. Consistent with these results, FLT3, HLF and JAG2 expression correlated with HOX A cluster gene expression in human leukemia samples. CONCLUSIONS: In conclusion this study has identified several novel Hox downstream target genes and provides important new leads to key regulators of the expansion and transformation of hematopoietic stem cells by Hox

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

The effect of plant growth regulators, cultivars and substrate combination on production of virus free potato minitubers

Nowadays large amounts of potato seed in the world is produced by in vitro virus free minitubers. Therefore, evaluation of commercial varieties in production of virus free potato minitubers is critical. In this study virus free plantlets of 4 potato cultivars of Agria, Marfona, Sante and Burren were achieved with meristem culture method. The meristem-derived plantlets which had optimum growth were transferred to the MS-medium without any growth regulators to stimulate the same vigor of the plantlets. Then DAS-ELISA test was conducted and the effects of different level of2 growth regulators either singly or in combination were evaluated on single node culture of potato. In all cultivars the best and most economical medium for single node culture was MS medium without growth regulators.Afterwards virus free plantlets were selected and transferred to the green house. The effects of substrate combination including 4 planting bed in minituber production were evaluated, after 90 days, numbers and diameters of minitubers for each cultivar were counted and recorded. Marfona had the greatest number of minitubers and Agria had the lowest. There are no any significant differences in minituber diameter between the cultivars. A mixture of peat moss and sand in the ratio of 1:1 wasproved to be the best for minituber production

Phase II randomised discontinuation trial of the MET/VEGF receptor inhibitor cabozantinib in metastatic melanoma

BACKGROUND: A phase II randomised discontinuation trial assessed cabozantinib (XL184), an orally bioavailable inhibitor of tyrosine kinases including VEGF receptors, MET, and AXL, in a cohort of patients with metastatic melanoma. METHODS: Patients received cabozantinib 100 mg daily during a 12-week lead-in. Patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumours (RECIST) at week 12 were randomised to cabozantinib or placebo. Primary endpoints were objective response rate (ORR) at week 12 and postrandomisation progression-free survival (PFS). RESULTS: Seventy-seven patients were enroled (62% cutaneous, 30% uveal, and 8% mucosal). At week 12, the ORR was 5% 39% of patients had SD. During the lead-in phase, reduction in target lesions from baseline was seen in 55% of evaluable patients overall and in 59% of evaluable patients with uveal melanoma. Median PFS after randomisation was 4.1 months with cabozantinib and 2.8 months with placebo (hazard ratio of 0.59; P=0.284). Median PFS from study day 1 was 3.8 months, 6-month PFS was 33%, and median overall survival was 9.4 months. The most common grade 3/4 adverse events were fatigue (14%), hypertension (10%), and abdominal pain (8%). One treatment-related death was reported from peritonitis due to diverticular perforation. CONCLUSIONS: Cabozantinib has clinical activity in patients with metastatic melanoma, including uveal melanoma. Further clinical investigation is warranted