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Gonzalo Machado‐Schiaffino Frederico Henning Axel Meyer 《Evolution; international journal of organic evolution》2014,68(7):2086-2091
The spectacular species richness of cichlids and their diversity in morphology, coloration, and behavior have made them an ideal model for the study of speciation and adaptive evolution. Hypertrophic lips evolved repeatedly and independently in African and Neotropical cichlid radiations. Cichlids with hypertrophic lips forage predominantly in rocky crevices and it has been hypothesized that mechanical stress caused by friction could result in larger lips through phenotypic plasticity. To test the influence of the environment on the size and development of lips, we conducted a series of breeding and feeding experiments on Midas cichlids. Full‐sibs of Amphilophus labiatus (thick‐lipped) and Amphilophus citrinellus (thin‐lipped) each were split into a control group which was fed food from the water column and a treatment group whose food was fixed to substrates. We found strong evidence for phenotypic plasticity on lip area in the thick‐lipped species, but not in the thin‐lipped species. Intermediate phenotypic values were observed in hybrids from thick‐ and thin‐lipped species reared under “control” conditions. Thus, both a genetic, but also a phenotypic plastic component is involved in the development of hypertrophic lips in Neotropical cichlids. Moreover, species‐specific adaptive phenotypic plasticity was found, suggesting that plasticity is selected for in recent thick‐lipped species. 相似文献
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Hicham Benzekri Paula Armesto Xavier Cousin Mireia Rovira Diego Crespo Manuel Alejandro Merlo David Mazurais Rocío Bautista Darío Guerrero-Fernández Noe Fernandez-Pozo Marian Ponce Carlos Infante Jose Luis Zambonino Sabine Nidelet Marta Gut Laureana Rebordinos Josep V Planas Marie-Laure Bégout M Gonzalo Claros Manuel Manchado 《BMC genomics》2014,15(1)
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Ivania Cerón-Souza Benjamin L. Turner Klaus Winter Ernesto Medina Eldredge Bermingham Gonzalo N. Feliner 《Plant Ecology》2014,215(5):481-493
Factors modulating introgressive hybridization between the red mangrove species Rhizophora mangle and R. racemosa in spatially defined sites are poorly understood. To investigate this, we evaluated the reproductive phenology and the nutrient and physiological traits in those two species and their F1 hybrids genotyped with microsatellite data across a natural hybrid zone from the Pacific coast of Panama. We found no evidence that reproductive phenology represents a barrier to gene flow, because R. mangle and the F1 hybrids produced flowers and propagules throughout the annual cycle, while R. racemosa flowered only in the dry season. Soil nutrient concentrations decreased landward, while soil salinity varied only slightly. Foliar nutrients and δ15N signatures varied according to the soil nutrient gradient, but only foliar phosphorus and carbon varied among species. In contrast, two structural variables (height and trunk diameter) and leaf variables related to salinity tolerance (Na, Cl:Na, K:Na, cation:anion) and water-use efficiency (i.e., δ13C) differed among species, suggesting higher salinity tolerance for R. mangle and F1 hybrids compared with R. racemosa. We conclude that parental species and F1 hybrids differ in salinity tolerance and water-use efficiency, which could be associated with adaptive evolution of the red mangrove hybrid complex. 相似文献
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Alejandra Martinez Gonzalo Peluffo Ariel A. Petruk Martín Hugo Dolores Pi?eyro Verónica Demicheli Diego M. Moreno Analía Lima Carlos Batthyány Rosario Durán Carlos Robello Marcelo A. Martí Nicole Larrieux Alejandro Buschiazzo Madia Trujillo Rafael Radi Lucía Piacenza 《The Journal of biological chemistry》2014,289(18):12760-12778
Trypanosoma cruzi, the causative agent of Chagas disease, contains exclusively iron-dependent superoxide dismutases (Fe-SODs) located in different subcellular compartments. Peroxynitrite, a key cytotoxic and oxidizing effector biomolecule, reacted with T. cruzi mitochondrial (Fe-SODA) and cytosolic (Fe-SODB) SODs with second order rate constants of 4.6 ± 0.2 × 104
m−1 s−1 and 4.3 ± 0.4 × 104
m−1 s−1 at pH 7.4 and 37 °C, respectively. Both isoforms are dose-dependently nitrated and inactivated by peroxynitrite. Susceptibility of T. cruzi Fe-SODA toward peroxynitrite was similar to that reported previously for Escherichia coli Mn- and Fe-SODs and mammalian Mn-SOD, whereas Fe-SODB was exceptionally resistant to oxidant-mediated inactivation. We report mass spectrometry analysis indicating that peroxynitrite-mediated inactivation of T. cruzi Fe-SODs is due to the site-specific nitration of the critical and universally conserved Tyr35. Searching for structural differences, the crystal structure of Fe-SODA was solved at 2.2 Å resolution. Structural analysis comparing both Fe-SOD isoforms reveals differences in key cysteines and tryptophan residues. Thiol alkylation of Fe-SODB cysteines made the enzyme more susceptible to peroxynitrite. In particular, Cys83 mutation (C83S, absent in Fe-SODA) increased the Fe-SODB sensitivity toward peroxynitrite. Molecular dynamics, electron paramagnetic resonance, and immunospin trapping analysis revealed that Cys83 present in Fe-SODB acts as an electron donor that repairs Tyr35 radical via intramolecular electron transfer, preventing peroxynitrite-dependent nitration and consequent inactivation of Fe-SODB. Parasites exposed to exogenous or endogenous sources of peroxynitrite resulted in nitration and inactivation of Fe-SODA but not Fe-SODB, suggesting that these enzymes play distinctive biological roles during parasite infection of mammalian cells. 相似文献
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Ricardo E. Gürtler María C. Cecere Gonzalo M. Vázquez-Prokopec Leonardo A. Ceballos Juan M. Gurevitz María del Pilar Fernández Uriel Kitron Joel E. Cohen 《PLoS neglected tropical diseases》2014,8(5)