Torres V.,University of Antofagasta
Journal of biotechnology | Year: 2010
Classic IRES sequences are notorious for exerting biased expression in favor of upstream coding regions when placed into polycistronic vectors. Here, we report the development of a bicistronic lentiviral system based on the 1D/2A sequence from the foot-and-mouth disease virus that is able to maintain tightly balanced control of upstream and downstream protein expression for several days at a stoichiometry very closely approaching 1.0. Our results suggest that the 1D/2A sequence can be optimized in an FUGW lentiviral setting to coordinate expression of multiple polypeptides, presenting a potentially valuable tool to signaling network researchers and to the gene therapy community.
Davila A.F.,Search for Extraterrestrial Intelligence Institute |
Zamorano P.,University of Antofagasta
Physical Biology | Year: 2013
Cancer disease is inherent to, and widespread among, metazoans. Yet, some of the hallmarks of cancer such as uncontrolled cell proliferation, lack of apoptosis, hypoxia, fermentative metabolism and free cell motility (metastasis) are akin to a prokaryotic lifestyle, suggesting a link between cancer disease and evolution. In this hypothesis paper, we propose that cancer cells represent a phenotypic reversion to the earliest stage of eukaryotic evolution. This reversion is triggered by the dysregulation of the mitochondria due to cumulative oxidative damage to mitochondrial and nuclear DNA. As a result, the phenotype of normal, differentiated cells gradually reverts to the phenotype of a facultative anaerobic, heterotrophic cell optimized for survival and proliferation in hypoxic environments. This phenotype matches the phenotype of the last eukaryotic common ancestor (LECA) that resulted from the endosymbiosis between an α-proteobacteria (which later became the mitochondria) and an archaebacteria. As such, the evolution of cancer within one individual can be viewed as a recapitulation of the evolution of the eukaryotic cell from fully differentiated cells to LECA. This evolutionary model of cancer is compatible with the current understanding of the disease, and explains the evolutionary basis for most of the hallmarks of cancer, as well as the link between the disease and aging. It could also open new avenues for treatment directed at reestablishing the synergy between the mitochondria and the cancerous cell. © 2013 IOP Publishing Ltd.
Ortiz M.,University of Antofagasta
Aquatic Conservation: Marine and Freshwater Ecosystems | Year: 2010
1. Dynamic and spatial models of the kelp forest off northern Chile (SE Pacific coast) were constructed using the Ecosim and Ecospace theoretical frameworks based on a previously mass-balanced trophic model using Ecopath II software. 2. The biomass of Macrocystis integrifolia and Lessonia trabeculata blades constituted the most relevant compartments or variables of the ecosystem studied. 3. The relative ascendency (A/C) of 35.5% suggests that this ecosystem is immature, but resistant to disturbances (e.g. fisheries). 4. The results obtained using mixed trophic impacts (MTI) show that both brown macroalgae produced relatively similar quantitative and qualitative effects, however, the predictions based on Ecosim clearly show that L. trabeculata experienced the most relevant direct and indirect effects. 5. The highest values of system recovery time obtained by Pinguipes chilensis and the other seastar group suggest that both compartments could be considered to be top predator species with strong top-down control. 6. The exploitation of kelp blades as a new harvest strategy appears to be ecologically sustainable. 7. The Ecospace trophic-spatially explicit model shows that exploitation exerted separately by habitat generates a similar pattern of direct and indirect effects. These results suggest that a habitat rotation of fisheries would not be justified. © 2010 John Wiley & Sons, Ltd.
Simirgiotis M.J.,University of Antofagasta
Molecules | Year: 2013
Liquid chromatography (LC) coupled with UV detection and electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was used for the generation of chemical fingerprints and the identification of phenolic compounds in peumo fruits and aerial parts from southern Chile. Thirty three compounds (19 of these detected in C. alba and 23 in C. monogyna) were identified, mainly flavonoid glycosides, phenolic acids, anthocyanins and flavonoid aglycons. Total phenolic content and total flavonoid content was measured for both species, and were higher in the extracts from C. monogyna fruits and aerial parts than extracts from C. alba. The fruits of Cryptocarya alba (Chilean peumo) presented high antioxidant capacity (9.12 ± 0.01 μg/mL in the DPPH assay), but was three times lower to that of Crataegus monogyna (German peumo) (3.61 ± 0.01 μg/mL in the DPPH assay). © 2013 by the authors.
Chavez R.A.,University of Antofagasta |
Oliva M.E.,University of Antofagasta
Parasitology Research | Year: 2011
A new nematode species, Philometra genypteri sp. n. (Philometridae), is described from male and female specimens found in the ovary of red cusk-eel, Genypterus chilensis (Guichenot) (Ophidiidae, Ophidiiformes), from the eastern South Pacific Ocean off the coast of northern Chile. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in the length of spicules (126-135 μm), a gubernaculum with dorsal lamella-like structures on its distal end, and the number and arrangement of genital papillae in the male. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by some morphological and biometrical features found in gravid female (absence of caudal projections, length of first-stage larvae or oesophagus, moderately developed anterior oesophageal inflation) and by the host type (fish family) and geographical distribution. P. genypteri is the first philometrid species reported from a fish belonging to the order Ophidiiformes and the second nominal species of Philometra recorded from marine fishes of the eastern South Pacific. © 2010 Springer-Verlag.