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Buenos Aires, Argentina

Tourmente M.,CSIC - National Museum of Natural Sciences | Tourmente M.,National University of Cardoba | Gomendio M.,CSIC - National Museum of Natural Sciences | Roldan E.R.S.,CSIC - National Museum of Natural Sciences
BMC Evolutionary Biology | Year: 2011

Background. The influence of sperm competition upon sperm size has been a controversial issue during the last 20 years which remains unresolved for mammals. The hypothesis that, when ejaculates compete with rival males, an increase in sperm size would make sperm more competitive because it would increase sperm swimming speed, has generated contradictory results from both theoretical and empirical studies. In addition, the debate has extended to which sperm components should increase in size: the midpiece to accommodate more mitochondria and produce more energy to fuel motility, or the principal piece to generate greater propulsion forces. Results. In this study we examined the influence of sperm competition upon sperm design in mammals using a much larger data set (226 species) than in previous analyses, and we corrected for phylogenetic effects by using a more complete and resolved phylogeny, and more robust phylogenetic control methods. Our results show that, as sperm competition increases, all sperm components increase in an integrated manner and sperm heads become more elongated. The increase in sperm length was found to be associated with enhanced swimming velocity, an adaptive trait under sperm competition. Conclusions. We conclude that sperm competition has played an important role in the evolution of sperm design in mammals, and discuss why previous studies have failed to detect it. © 2011 Tourmente et al; licensee BioMed Central Ltd. Source


Avila M.L.,CONICET | Tekiel V.,CONICET | Moretti G.,CONICET | Nicosia S.,CONICET | And 5 more authors.
Parasites and Vectors | Year: 2011

Background. Triatoma infestans is the most relevant vector of Chagas disease in the southern cone of South America. Since its genome has not yet been studied, sequencing of Expressed Sequence Tags (ESTs) is one of the most powerful tools for efficiently identifying large numbers of expressed genes in this insect vector. Results. In this work, we generated 826 ESTs, resulting in an increase of 47% in the number of ESTs available for T. infestans. These ESTs were assembled in 471 unique sequences, 151 of which represent 136 new genes for the Reduviidae family. Conclusions. Among the putative new genes for the Reduviidae family, we identified and described an interesting subset of genes involved in development and reproduction, which constitute potential targets for insecticide development. © 2011 Avila et al; licensee BioMed Central Ltd. Source


Comba A.,National University of Cardoba | Comba A.,CONICET | Maestri D.M.,CONICET | Berra M.A.,National University of Cardoba | And 6 more authors.
Lipids in Health and Disease | Year: 2010

Background. Nutritional factors play a major role in cancer initiation and development. Dietary polyunsaturated fatty acids (PUFAs) have the ability to induce modifications in the activity of lipoxygenase (LOX) and cyclooxygenase (COX) enzymes that affect tumour growth. We studied the effect of two diets enriched in 6% Walnut and Peanut oils that are rich in -3 and 9 PUFAs respectively on a murine mammary gland adenocarcinoma as compared with the control (C) that received commercial diet. Results. Peanut oil enriched diet induced an increase in membrane arachidonic acid (AA) content and the cyclooxygenase enzyme derived 12-HHT (p < 0.05) and simultaneously showed decrease in 12-LOX, 15-LOX-2, 15-LOX-1 and PGE activities (p < 0.05) that corresponded to higher apoptosis and lower mitosis seen in this group (p < 0.05). Furthermore, Peanut oil group showed lower T-cell infiltration (p < 0.05), number of metastasis (p < 0.05) and tumour volume (p < 0.05) and longer survival rate compared to other groups. Conclusions. The results of the present study showed that Peanut oil-enriched diet protects against mammary cancer development by modulating tumour membrane fatty acids composition and LOX and COX enzyme activities. © 2010 Comba et al; licensee BioMed Central Ltd. Source

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