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Acosta-Maspons A.,National Autonomous University of Mexico | Sepulveda-Garcia E.,National Autonomous University of Mexico | Sanchez-Baldoquin L.,National Autonomous University of Mexico | Sanchez-Baldoquin L.,University of Habana | And 3 more authors.
Planta | Year: 2014

Metacaspases are cysteine proteases present in plants, fungi, prokaryotes, and early branching eukaryotes, although a detailed description of their cellular function remains unclear. Currently, three-dimensional (3D) structures are only available for two metacaspases: Trypanosoma brucei (MCA2) and Saccharomyces cerevisiae (Yca1). Furthermore, metacaspases diverged from animal caspases of known structure, which limits straightforward homology-based interpretation of functional data. We report for the first time the identification and initial characterization of a metacaspase of Nicotiana tabacum L., NtMC1. By combining domain search, multiple sequence alignment (MSA), and protein fold-recognition studies, we provide compelling evidences that NtMC1 is a plant metacaspase type II, and predict its 3D structure using the crystal structure of two type I metacaspases (MCA2 and Yca1) and Gsu0716 protein from Geobacter sulfurreducens as template. Analysis of the predicted 3D structure allows us to propose Asp353, at the putative p10 subunit, as a new member of the aspartic acid triad that coordinates the P1 arginine/lysine residue of the substrate. Nevertheless, site-directed mutagenesis and expression analysis in bacteria and Nicotiana benthamiana indicate the functionality of both Asp348 and Asp353. Through the co-expression of mutant and wild-type proteins by transient expression in N. benthamiana leaves we found that polypeptide processing seems to be intramolecular. Our results provide the first evidence in plant metacaspases concerning the functionality of the putative p10 subunit. © 2013 Springer-Verlag Berlin Heidelberg.

Torres D.,Pedro de Valdivia University | Acevedo J.,University of Magallanes | Torres D.E.,University of the Americas in Chile | Aguayo-Lobo A.,Instituto Antartico Chileno INACH
Polar Biology | Year: 2012

A vagrant adult male Subantarctic fur seal Arctocephalus tropicalis was observed among Antarctic fur seals A. gazella at Cape Shirreff, Livingston Island, Antarctica, which is located to ~4,190 and ~5,939 km from the nearest breeding colonies of Subantarctic fur seals. Although the colony of origin of this animal and the reason for its movement outside its distribution range are unknown, this sighting shows the high dispersal capacity of this species and provides an insight into possible changes in its distribution. Although this vagrant was not observed with females Antarctic fur seal, news sightings in the future could result in viable hybrid, and introgressive hybridization could represent a threat for Cape Shirreff population recovery, if still the population way to go to recover to presailing levels. © 2011 Springer-Verlag.

Navarro J.-C.,Laboratory Of Entomologia | Navarro J.-C.,Central University of Venezuela | Ponce P.,Instituto Nacional Of Investigacion En Salud Publica Inspi | Ponce P.,University of the Americas in Chile | Cevallos V.,Instituto Nacional Of Investigacion En Salud Publica Inspi
Boletin de Malariologia y Salud Ambiental | Year: 2013

Two new records of mosquitoes (Diptera: Culicidae) are presented from Ecuador, and both potential vectors of yellow fever virus and Mayaro. Sabethes amazonicus Gordon and Evans and Haemagogus anastasionis Dyar adults were collected in a locality in the province of Zamora-Chinchipe, in which there have been cases of yellow fever previously. This finding shows the importance of further studies of baseline vector in the country, geographical distribution and ecological aspects and possible epidemiological link with emerging and reemerging diseases.

Oberpaur C.,Santo Tomas University of Chile | Puebla V.,Santo Tomas University of Chile | Vaccarezza F.,Santo Tomas University of Chile | Arevalo M.E.,University of the Americas in Chile
Ciencia e Investigacion Agraria | Year: 2010

Nursery producers grow plants in containers, mainly using substrates based on peat. In order to replace the use of peat, diverse mixtures of substrates combining different proportions of the moss Sphagnum magellanicum Brid. (40, 50 and 60%) and alternative organic materials, such as compost, humus and composted pine bark, were tested. In the first trial under laboratory conditions, conducted in October 2006, the physicochemical characteristics of nine initial mixtures, including a control, were determined. Five mixtures, with similar physicochemical conditions as the control, and a commercial peat mixture, were selected by the application of Euclidean minimum distances. The finally selected mixtures were three combinations of moss with composted pine bark (60 - 40, 50 - 50 and 40 - 60), a mixture composed of 60% moss and 40% humus and a mixture of 60% moss and 40% compost. In the second trial, under nursery shade conditions, conducted in December 2006, the selected mixtures were sown with lettuce seeds in a complete randomized block statistical design with six treatments and five replicates. The emergence rate, number of leaves, plant height, canopy weight and root dry weight were evaluated. The results, analyzed by ANOVA and the multiple comparisons test of Duncan (p ≤ 0.05), indicated that it is feasible to use the mixtures composed of 60% moss + 40% humus and 60% moss + 40% compost.

The effect of dietary β-1.3-glucan, vitamin E, and β-carotene supplements in juvenile brown shrimp, Farfantepenaeus californiensis, inoculated with white spot syndrome virus (WSSV) was evaluated. Groups of 30 organisms (weighing 1 ± 0.5 g) were cultured in 60 L fiberglass tanks and fed daily with β-1.3- glucan (0.1%), vitamin E (0.01%), and β-carotene (0.01%) for 23 days; the specimens were then inoculated with WSSV. The antioxidant activity of the enzymes superoxide dismutase (SOD) and catalase (CAT) were determined in the hepatopancreas and muscle at 0, 1, 6, 12, 24, and 48 h after inoculation. Shrimp fed with β-1.3-glucan, vitamin E, and β-carotene significantly increased SOD activity in the hepatopancreas and muscle at 12 and 24 h post-infection, respectively. Shrimp fed with vitamin E and β-1.3-glucan registered an increment in SOD activity from 12 to 48 h post-infection. Shrimp fed with β-carotene increased SOD activity before infection with WSSV, and shrimp fed with β-1.3-glucan and vitamin E increased CAT activity, also before infection. The CAT activity response in shrimp muscle increased with respect to the control group for all treatments tested from 1 to 6 h after inoculation with WSSV. The highest antioxidant response was registered in shrimp fed with vitamin E. Juvenile shrimp fed with vitamin E and later inoculated with WSSV registered 100% mortality at 72 h, but shrimp fed with β-1.3-glucan and β-carotene showed greater resistance to WSSV, with mortality at 144 h post-infection. This study demonstrated the capacity of juvenile Farfantepenaeus californiensis fed β-1.3-glucan, vitamin E, or β-carotene to increase the antioxidant response before and after viral infection.

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