Molecular Evolution of the Neuropeptide S Receptor

The neuropeptide S receptor (NPSR) is a recently deorphanized member of the G protein-coupled receptor (GPCR) superfamily and is activated by the neuropeptide S (NPS). NPSR and NPS are widely expressed in central nervous system and are known to have crucial roles in asthma pathogenesis, locomotor activity, wakefulness, anxiety and food intake. The NPS-NPSR system was previously thought to have first evolved in the tetrapods. Here we examine the origin and the molecular evolution of the NPSR using in-silico comparative analyses and document the molecular basis of divergence of the NPSR from its closest vertebrate paralogs. In this study, NPSR-like sequences have been identified in a hemichordate and a cephalochordate, suggesting an earlier emergence of a NPSR-like sequence in the metazoan lineage. Phylogenetic analyses revealed that the NPSR is most closely related to the invertebrate cardioacceleratory peptide receptor (CCAPR) and the group of vasopressin-like receptors. Gene structure features were congruent with the phylogenetic clustering and supported the orthology of NPSR to the invertebrate NPSR-like and CCAPR. A site-specific analysis between the vertebrate NPSR and the well studied paralogous vasopressin-like receptor subtypes revealed several putative amino acid sites that may account for the observed functional divergence between them. The data can facilitate experimental studies aiming at deciphering the common features as well as those related to ligand binding and signal transduction processes specific to the NPSR

Evaluation of a polymerase chain reaction protocol for the detection of Salmonella species directly from superficial samples of chicken carcasses and preenrichment broth

Chicken meat is an important vehicle of foodborne pathogens, such as Salmonella spp., and demands a systematic control of microbiological contamination during industrial processing. This control occurs by the adoption of quality control systems in slaughters based on the microbiological investigation on hygiene indicators and pathogens, requiring the development of fast, trustable, and precise methodologies. The objective of this study was to compare the Salmonella spp. conventional methodology to a protocol of PCR in chicken carcass surface samples. The PCR protocol was developed directly from the collected samples and from preenrichment broth before and after incubation. The obtained results were compared by χ2 and McNemar tests (P 0.05), the PCR developed from preenrichment after incubation presented significant differences from all the other methodologies (P < 0.05). Wide variations were observed in the PCR performance for Salmonella spp. detection in chicken carcasses, which can be due to intrinsic factors inherent to the achievement of this food. Further studies are necessary to elucidate the applicability of the PCR as a tool for microbiological monitoring in quality control systems for chicken processing