Hybridizations between closely related species commonly occur in the domestication process of many crops. Banana cultivars are derived from such hybridizations between species and subspecies of the Musa genus that have diverged in various tropical Southeast Asian regions and archipelagos. Among the diploid and triploid hybrids generated, those with seedless parthenocarpic fruits were selected by humans and thereafter dispersed through vegetative propagation.
View Article and Find Full Text PDFBackground And Aims: Banana cultivars are derived from hybridizations involving Musa acuminata subspecies. The latter diverged following geographical isolation in distinct South-east Asian continental regions and islands. Observation of chromosome pairing irregularities in meiosis of hybrids between these subspecies suggested the presence of large chromosomal structural variations.
View Article and Find Full Text PDFMost banana cultivars are triploid seedless parthenocarpic clones derived from hybridization between Musa acuminata subspecies and sometimes M. balbisiana. M.
View Article and Find Full Text PDFStarch is the most widespread and abundant storage carbohydrate in plants. It is also a major feature of cultivated bananas as it accumulates to large amounts during banana fruit development before almost complete conversion to soluble sugars during ripening. Little is known about the structure of major gene families involved in banana starch metabolism and their evolution compared to other species.
View Article and Find Full Text PDFThis study aims to understand the genetic diversity of traditional Oceanian starchy bananas in order to propose an efficient conservation strategy for these endangered varieties. SSR and DArT molecular markers are used to characterize a large sample of Pacific accessions, from New Guinea to Tahiti and Hawaii. All Pacific starchy bananas are shown of New Guinea origin, by interspecific hybridization between Musa acuminata (AA genome), more precisely its local subspecies M.
View Article and Find Full Text PDFWhole-genome duplications (WGDs) are widespread in plants, and three lineage-specific WGDs occurred in the banana (Musa acuminata) genome. Here, we analysed the impact of WGDs on the evolution of banana gene families involved in ethylene biosynthesis and signalling, a key pathway for banana fruit ripening. Banana ethylene pathway genes were identified using comparative genomics approaches and their duplication modes and expression profiles were analysed.
View Article and Find Full Text PDF• The semi-aquatic legumes belonging to the genus Aeschynomene constitute a premium system for investigating the origin and evolution of unusual symbiotic features such as stem nodulation and the presence of a Nod-independent infection process. This latter apparently arose in a single Aeschynomene lineage. But how this unique Nod-independent group then radiated is not yet known.
View Article and Find Full Text PDFBackground: Banana (genus Musa) is a crop of major economic importance worldwide. It is a monocotyledonous member of the Zingiberales, a sister group of the widely studied Poales. Most cultivated bananas are natural Musa inter-(sub-)specific triploid hybrids.
View Article and Find Full Text PDFCorynebacterium (C.) macginleyi is a gram positive, lipophilic rod, usually considered a colonizer of skin and mucosal surfaces. Several reports have associated C.
View Article and Find Full Text PDFSimple sequence repeat (SSR) markers are widely used tools for inferences about genetic diversity, phylogeography and spatial genetic structure. Their applications assume that variation among alleles is essentially caused by an expansion or contraction of the number of repeats and that, accessorily, mutations in the target sequences follow the stepwise mutation model (SMM). Generally speaking, PCR amplicon sizes are used as direct indicators of the number of SSR repeats composing an allele with the data analysis either ignoring the extent of allele size differences or assuming that there is a direct correlation between differences in amplicon size and evolutionary distance.
View Article and Find Full Text PDFBananas (Musa spp.), including dessert and cooking types, are giant perennial monocotyledonous herbs of the order Zingiberales, a sister group to the well-studied Poales, which include cereals. Bananas are vital for food security in many tropical and subtropical countries and the most popular fruit in industrialized countries.
View Article and Find Full Text PDFWe hypothesized that chelating Gd(III) to 1,4,7-tris(carboxymethylaza)cyclododecane-10-azaacetylamide (DO3A) on peptide nucleic acid (PNA) hybridization probes would provide a magnetic resonance genetic imaging agent capable of hybridization to a specific mRNA. Because of the low sensitivity of Gd(III) as an magnetic resonance imaging (MRI) contrast agent, a single Gd-DO3A complex per PNA hybridization agent could not provide enough contrast for detection of cancer gene mRNAs, even at thousands of mRNA copies per cell. To increase the Gd(III) shift intensity of MRI genetic imaging agents, we extended a novel DO3An-polydiamidopropanoyl (PDAPm) dendrimer, up to n = 16, from the N-terminus of KRAS PNA hybridization agents by solid phase synthesis.
View Article and Find Full Text PDFUnlabelled: Among U.S. men, prostate cancer (PC) accounts for 29% of all newly diagnosed cancers.
View Article and Find Full Text PDFUnlabelled: Treatment of breast cancer is hampered by a large unmet need for rapid, sensitive, specific staging and stratification of palpable and nonpalpable abnormalities. Mammography and physical examination miss many early breast cancers, yet detect many benign lesions. Cyclin D1, encoded by CCND1 messenger RNA (mRNA), and insulin-like growth factor 1 receptor (IGF1R) are key regulators of cell proliferation that are overexpressed in most breast cancers.
View Article and Find Full Text PDFVasoactive intestinal peptide and pituitary adenylate cyclase activating peptide have high affinity for VPAC1, VPAC2 and PAC1 receptors overexpressed on human cancer cells. Four potent analogues of these peptides, TP3939, TP3982, TP4200 and TP3805 were labeled with (64)Cu and evaluated ex vivo and in vivo to asses their biological activity and receptor specificity. The ultimate goal is to utilize (64)Cu analogues for positron emission tomography (PET) imaging of breast cancers in humans.
View Article and Find Full Text PDFThere is a compelling need to image pancreas cancer at an early stage. Human pancreas cancer cells display elevated levels of KRAS protein due to high copy numbers of KRAS mRNA, and elevated levels of insulin-like growth factor 1 receptor (IGF1R) due to overexpression of IGF1R mRNA. Therefore we hypothesized that pancreas cancer could be detected in vivo with a single probe that targets both KRAS mRNA and IGF1R.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
April 2007
Purpose: To determine the effect of vascular endothelial growth factor VEGF Trap (Regeneron Pharmaceuticals, Tarrytown, NY), a humanized soluble vascular endothelial growth factor (VEGF) receptor protein, and radiation (RT) on tumor growth in U87 glioblastoma xenografts in nude mice.
Methods And Materials: U87 cell suspensions were implanted subcutaneously into hind limbs of nude mice. VEGF Trap (2.
Early external detection of cancer gene activity might enable early treatment of cancer and might reduce cancer mortality. We hypothesized that oncogene mRNA overexpressed at thousands of copies per malignant cell in a zone of transformed cells could be imaged externally by scintigraphic imaging, PET (positron emission tomography) or MRI (magnetic resonance imaging) with PNA (peptide nucleic acid) hybridization probes that include chelators for metal cations and a cyclized peptide analogue of IGF-1 (insulin-like growth factor 1), D(Cys-Ser-Lys-Cys), to mediate internalization by IGF1R (IGF-1 receptor) overexpressed on cancer cells. We observed that human MCF7 breast cancer cells that overexpress IGF1R efficiently internalized fluorescein-chelator-PNA-D(Cys-Ser-Lys-Cys) to the cytoplasm, but not with D(Cys-Ala-Ala-Cys).
View Article and Find Full Text PDFBackground: The antiangiogenic approach to controlling cancer requires a better understanding of angiogenesis and the discovery of new compounds that modulate this key biological process. Here we investigated the role of endorepellin, an angiostatic protein fragment that is derived from the C-terminus of perlecan, a heparan sulfate proteoglycan, in controlling tumor angiogenesis in vivo.
Methods: We administered human recombinant endorepellin systemically to mice bearing orthotopic squamous carcinoma xenografts or syngeneic Lewis lung carcinoma tumors.
Decorin is not only a regulator of matrix assembly but also a key signaling molecule that modulates the activity of tyrosine kinase receptors such as the epidermal growth factor receptor (EGFR). Decorin evokes protracted internalization of the EGFR via a caveolar-mediated endocytosis, which leads to EGFR degradation and attenuation of its signaling pathway. In this study, we tested if systemic delivery of decorin protein core would affect the biology of an orthotopic squamous carcinoma xenograft.
View Article and Find Full Text PDFPurpose: Arterial input function (AIF) measurement for quantification of small animal PET studies is technically challenging and limited by the small blood volume of small laboratory animals. The present study investigated the use of a standard arterial input function (SAIF) to simplify the experimental procedure.
Methods: Twelve [(18)F]fluorodeoxyglucose ([(18)F]FDG) PET studies accompanied by serial arterial blood sampling were acquired in seven male Sprague-Dawley rats under isoflurane anaesthesia without (every rat) and with additional (five rats) vibrissae stimulation.
In 2005, breast cancer will kill approximately 40,410 women in the U.S., and pancreatic cancer will kill approximately 31,800 men and women in the U.
View Article and Find Full Text PDFThe evolution of positron emission tomography (PET) imaging for small animals has led to the development of dedicated PET scanner designs with high resolution and sensitivity. The animal PET scanner achieves these goals for imaging small animals such as mice and rats. The scanner uses a pixelated Anger-logic detector for discriminating 2 x 2 x 10 mm3 crystals with 19-mm-diameter photomultiplier tubes.
View Article and Find Full Text PDFIntroduction: Fully three-dimensional (3-D) reconstruction algorithms have the potential to better utilize PET data acquired in true 3-D acquisition modes, as compared to 2-D approaches involving data reduction through rebinning procedures followed by a 2-D or 2.5-D reconstruction. Our previous studies, involving simulated and real phantom data from PET scanners working purely in 3-D acquisition mode, showed that the fully 3-D reconstruction approaches bring appreciable improvement on physical measures and visual image quality as well.
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