Evolutionary pattern in the OXT-OXTR system in primates: Coevolution and positive selection footprints
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Authors: Vargas-Pinilla, Pedro; Paixao-Cortes, Vanessa Rodrigues; Pare, Pamela; Tovo-Rodrigues, Luciana; de Alencar Gadelha Vieira, Carlos Meton; Xavier, Agatha; Comas, David; Pissinatti, Alcides; Sinigaglia, Marialva; Rigo, Mauricio Menegatti; Vieira, Gustavo Fioravanti; Lucion, Aldo B.; Salzano, Francisco Mauro; Bortolini, Maria Catira
Abstract
Oxytocin is a nonapeptide involved in a wide range of physiologic and behavioral functions. Until recently, it was believed that an unmodified oxytocin sequence was present in all placental mammals. This study analyzed oxytocin (OXT) in 29 primate species and the oxytocin receptor (OXTR) in 21 of these species. We report here three novel OXT forms in the New World monkeys, as well as a more extensive distribution of a previously described variant (Leu8Pro). In structural terms, these OXTs share the same three low-energy conformations in solution during molecular dynamic simulations, with subtle differences in their side chains. A consistent signal of positive selection was detected in the Cebidae family, and OXT position 8 showed a statistically significant (P = 0.013) correlation with litter size. Several OXTR changes were identified, some of them promoting gain or loss of putative phosphorylation sites, with possible consequences for receptor internalization and desensitization. OXTR amino acid sites are under positive selection, and intramolecular and intermolecular coevolutionary processes with OXT were also detected. We suggest that some New World monkey OXT-OXTR forms can be correlated to male parental care through the increase of cross-reactivity with its correlated vasopressin system.
Simultaneous quantification of antibiotics in wastewater from pig farms by capillary electrophoresis
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
Authors: Diaz-Quiroz, Carlos A.; Francisco Hernandez-Chavez, J.; Ulloa-Mercado, Gabriela; Gortares-Moroyoqui, Pablo; Martinez-Macias, Rosario; Meza-Escalante, Edna; Serrano-Palacios, Denisse
Abstract
Pig farming is an important activity in the economic development of Mexico with millions of tons of meat produced annually. Antibiotics are used in therapeutic dose to prevent diseases, and sometimes as growth promoters. These compounds are not completely metabolized; they are carried into the environment in its active form at concentrations that could induce antibiotic resistance in bacteria, which could be transferred to human pathogens by horizontal gene transfer. The objective of this work was to develop methods of analysis for simultaneous quantification of the antibiotics Oxytetracycline (OXT), Chlortetracycline (CLT), Enrofloxacin (ENRO) and Ciprofloxacin (CIPRO) by field-amplified sampling injection in capillary zone electrophoresis (FASICZE). The method was validated by parameters of (1) linearity, obtaining a lineal range of 0.05 at 1 mu g mL(-1) for ENRO and CIPRO, and from 0.1 to 1 mu g mL(-1) for OXT and CLT; (2) precision, obtaining values < 5% of standard deviation for CIPRO and ENRO and < 10% of standard deviation for OXT and CLT; (3) accuracy, with recovery values from 93 to 115%; (4) selectivity, with values of resolution > 2 for the all antibiotics tested. To prove the method, a sample of wastewater from a local pig farm was analyzed, detecting a concentration of 0.140 +/- 0.009 for OXT. This concentration was higher than the minimal selective concentration, indicating the point in which resistance to a determined antibiotic could develop. The methods were validated with precision and sensitivity comparable to chromatographic methods, which can be used to analyze wastewater from pig farms directly.