Widespread Triploidy in Western North American Aspen (Populus tremuloides)

We document high rates of triploidy in aspen (Populus tremuloides) across the western USA (up to 69% of genets), and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species), climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our evidence suggests that these phenomena are unlikely to be significant contributors to our observed patterns. We suggest that the distribution of triploid aspen is due to a positive synergy between triploidy and ecological factors driving clonality. Although triploids are expected to have low fertility, they are hypothesized to be an evolutionary link to sexual tetraploidy. Thus, interactions between clonality and polyploidy may be a broadly important component of geographic speciation patterns in perennial plants. Further, cytotypes are expected to show physiological and structural differences which may influence susceptibility to ecological factors such as drought, and we suggest that cytotype may be a significant and previously overlooked factor in recent patterns of high aspen mortality in the southwestern portion of the species range. Finally, triploidy should be carefully considered as a source of variance in genomic and ecological studies of aspen, particularly in western U.S. landscapes.     

Pathophysiological relationship between hypoxia associated oxidative stress,Epithelial-mesenchymal transition,stemness acquisition and alteration of Shh/ Gli-1 axis during oral sub-mucous fibrosis and oral squamous cell carcinoma

Oral sub-mucous fibrosis (OSF) is a pathophysiological state of oral cavity or oropharynx having a high chance of conversion to oral squamous cell carcinoma (OSCC). It involves fibrotic transformation of sub-epithelial matrix along with epithelial abnormalities. The present work aims to unveil the mechanistic domain regarding OSF to OSCC conversion exploring the scenario of hypoxia associated oxidative stress, epithelial-mesenchymal transition (EMT), metastasis and stemness acquisition. The study involves histopathological analysis of the diseased condition along with the exploration of oxidative stress status, assessment of mitochondrial condition, immunohistochemical analysis of HIF-1α, E-cadherin, vimentin, ERK, ALDH-1, CD133, Shh, Gli-1 and survivin expressions in the oral epithelial region together with the quantitative approach towards collagen deposition in the sub-epithelial matrix. Oxidative stress was found to be associated with type-II EMT in case of OSF attributing the development of sub-epithelial fibrosis and type-III EMT in case of OSCC favoring malignancy associated metastasis. Moreover, the acquisition of stemness during OSCC can also be correlated with EMT. Alteration of Shh and Gli-1 expression pattern revealed the mechanistic association of hypoxia with the phenotypic plasticity and disease manifestation in case of OSF as well as OSCC. Shh/ Gli-1 signaling can also be correlated with survivin mediated cytoprotective phenomenon under oxidative stress. Overall, the study established the correlative network of hypoxia associated oxidative stress, EMT and manifestation of oral pre-cancerous and cancerous condition in a holistic approach that may throw rays of hope in the therapeutic domain of the concerned diseases.     

RUNX1T1, a potential prognostic marker in breast cancer,is co-ordinately expressed with ERα, and regulated by estrogen receptor signalling in breast cancer cells

Molecular Biology Reports - RUNX1T1 is extensively studied in the context of AML1-RUNX1T1 fusion protein in acute myeloid leukemia. Little is known about the function of RUNX1T1 itself, although...     

Development and validation of multiplex-PCR assay to simultaneously detect favourable alleles of shrunken2, opaque2, crtRB1 and lcyE genes in marker-assisted selection for maize biofortification

Journal of Plant Biochemistry and Biotechnology - Sweet corn has emerged as a popular vegetable worldwide. Commercial shrunken2 (sh2)-based sweet corn lacks lysine, tryptophan and provitamin-A,...     

Circulating plasma microRNAs in colorectal neoplasia: A pilot study in assessing response to therapy

IntroductionCurrent serological surveillance markers to monitor colorectal cancer (CRC) or colorectal advanced adenomas (CAA) are hampered by poor sensitivity and specificity. The aim of this study is to identify and validate a panel of plasma microRNAs which change in expression after resection of such lesions.MethodsA prospectively maintained colorectal surgery database was queried for patients in whom both pre- and post-procedural serum samples had been obtained. An initial screening analysis of CRC and CAA patients (5 each) was conducted using screening cards for 380 miRNAs. Four identified miRNAs were combined with a previously described panel of 7 miRNAs that were diagnostically predictive of CRC and CAA. Differential miRNA expression was assessed using quantitative real-time polymerase chain reaction(qRT-PCR).ResultsFifty patients were included (n = 27 CRC, n = 23 CAA). There was no difference in age, gender, or race profile of CRC patients compared to CAA patients. Six miRNA were significantly increased after CRC resection (miR-324, let7b, miR-454, miR-374a, miR-122, miR-19b, all p<0.05), while three miRNAs were significantly increased following CAA resection (miR-454, miR-374a, miR-122, all p<0.05). Three miRNA were increased in common for both (miR-454, miR-374a, miR-122).DiscussionThe expression of miRNAs associated with neoplasia (either CRC or CAA) was significantly increased following surgical resection or endoscopic removal of CRC or CAA. Future studies should focus on the evaluation of these miRNAs in CRC and CAA prognosis.     

Consequences of MnSOD interactions with nitric oxide: Nitric oxide dismutation and the generation of peroxynitrite and hydrogen peroxide

The present study demonstrates that manganese superoxide dismutase (MnSOD) (Escherichia coli), binds nitric oxide (^√NO) and stimulates its decay under both anaerobic and aerobic conditions. The results indicate that previously observed MnSOD-catalyzed ^√NO disproportionation (dismutation) into nitrosonium (NO⁺) and nitroxyl (NO^? ) species under anaerobic conditions is also operative in the presence of molecular oxygen. Upon sustained aerobic exposure to ^√NO, MnSOD-derived NO^? species initiate the formation of peroxynitrite (ONOO^? ) leading to enzyme tyrosine nitration, oxidation and (partial) inactivation. The results suggest that both ONOO^? decomposition and ONOO^? -dependent tyrosine residue nitration and oxidation are enhanced by metal centre-mediated catalysis. We show that the generation of ONOO^? is accompanied by the formation of substantial amounts of H₂O₂. MnSOD is a critical mitochondrial antioxidant enzyme, which has been found to undergo tyrosine nitration and inactivation in various pathologies associated with the overproduction of ^√NO. The results of the present study can account for the molecular specificity of MnSOD nitration in vivo. The interaction of ^√NO with MnSOD may represent a novel mechanism by which MnSOD protects the cell from deleterious effects associated with overproduction of ^√NO.     

The Novel 6–(N-Pyrrolyl)purine Acyclic Nucleosides: 1H and 13C NMR and X-ray Structural Study†

Abstract

Synthesis of the novel nucleoside analogues containing exocyclic pyrrolo moiety and acyclic side chains attached to the purine ring at N-9 and N-7 is described. The site of alkylation was determined by ¹H and ¹³C NMR on the basis of chemical shifts, C-H coupling constants and connectivity in NOESY and HETCOR spectra. The N-9 substitution of 7 was proved by its X-ray crystallographic analysis.

     

Distribution and development of P2Y1-purinoceptors in the mouse retina

There is increasing evidence that ATP acts on purinergic receptors and mediates synaptic transmission in the retina. In a previous study, we raised the possibility that P2X-purinoceptors, presumably P2X₂-purinoceptors in OFF-cholinergic amacrine cells, play a key role in the formation of OFF pathway-specific modulation. In this study, we examined whether the P2Y₁-purinoceptors can function in cholinergic amacrine cells in the mouse retina since cholinergic amacrine cells in the rat retina express P2Y₁-purinoceptors. P2Y₁-purinoceptors were shown to be expressed in dendrites of both ON- and OFF-cholinergic amacrine cells in adults. At postnatal day 7, there was immunoreactivity for P2Y₁-purinoceptors in the soma of cholinergic amacrine cells. At postnatal day 14, weak immunoreactivity for P2Y₁-purinoceptors was detected in the dendrites but not in the soma of cholinergic amacrine cells. At postnatal day 21, strong immunoreactivity for P2Y₁-purinoceptors was detected in dendrites of cholinergic amacrine cells. The expression pattern of P2Y₁-purinoceptors was not affected by visual experience. We concluded that P2Y₁-purinoceptors are not involved in the OFF-pathway-specific signal transmission in cholinergic amacrine cells of the mouse retina.