Fishing Into the MicroRNA Transcriptome.

In the last decade, several studies have been focused on revealing the microRNA (miRNA) repertoire and determining their functions in farm animals such as poultry, pigs, cattle, and fish. These small non-protein coding RNA molecules (18-25 nucleotides) are capable of controlling gene expression by binding to messenger RNA (mRNA) targets, thus interfering in the final protein output. MiRNAs have been recognized as the main regulators of biological features of economic interest, including body growth, muscle development, fat deposition, and immunology, among other highly valuable traits, in aquatic livestock. Currently, the miRNA repertoire of some farmed fish species has been identified and characterized, bringing insights about miRNA functions, and novel perspectives for improving health and productivity. In this review, we summarize the current advances in miRNA research by examining available data on Neotropical and other key species exploited by fisheries and in aquaculture worldwide and discuss how future studies on Neotropical fish could benefit from this knowledge. We also make a horizontal comparison of major results and discuss forefront strategies for miRNA manipulation in aquaculture focusing on forward-looking ideas for forthcoming research.

Combining Results from Distinct MicroRNA Target Prediction Tools Enhances the Performance of Analyses.

Target prediction is generally the first step toward recognition of bona fide microRNA (miRNA)-target interactions in living cells. Several target prediction tools are now available, which use distinct criteria and stringency to provide the best set of candidate targets for a single miRNA or a subset of miRNAs. However, there are many false-negative predictions, and consensus about the optimum strategy to select and use the output information provided by the target prediction tools is lacking. We compared the performance of four tools cited in literature-TargetScan (TS), miRanda-mirSVR (MR), Pita, and RNA22 (R22), and we determined the most effective approach for analyzing target prediction data (individual, union, or intersection). For this purpose, we calculated the sensitivity, specificity, precision, and correlation of these approaches using 10 miRNAs (miR-1-3p, miR-17-5p, miR-21-5p, miR-24-3p, miR-29a-3p, miR-34a-5p, miR-124-3p, miR-125b-5p, miR-145-5p, and miR-155-5p) and 1,400 genes (700 validated and 700 non-validated) as targets of these miRNAs. The four tools provided a subset of high-quality predictions and returned few false-positive predictions; however, they could not identify several known true targets. We demonstrate that union of TS/MR and TS/MR/R22 enhanced the quality of in silico prediction analysis of miRNA targets. We conclude that the union rather than the intersection of the aforementioned tools is the best strategy for maximizing performance while minimizing the loss of time and resources in subsequent in vivo and in vitro experiments for functional validation of miRNA-target interactions.

Prevalence of C282Y and H63D mutations in the HFEgene in patients from São Paulo and Southern Brazil / Prevalência das mutações C282Y e H63D no gene HFEem pacientes de São Paulo e do Sul do Brasil

ABSTRACT Hereditary hemochromatosis (HH) is an autosomal recessive disorder caused by mutations in the HFE gene; it is characterized by the risk of iron overload. C282Y and H63D are the most associated mutations in HH. This study aimed to determine the frequency of mutations in the south of Brazil and São Paulo. It used the real-time polymerase chain reaction (PCR) technique and the results collected from Genolab data. In 90 individuals, 46.67% had at least one of the mutations for HH. There is a high prevalence of these mutations in both populations, therefore searching for patients under clinical suspicion is recommended.

RESUMO A hemocromatose hereditária (HH) é uma desordem autossômica recessiva provocada por mutações no gene HFE e caracterizada pelo risco de uma sobrecarga de ferro. As mutações mais conhecidas associadas à HH são a C282Ye a H63D. Este estudo teve como objetivo determinar a frequência das mutações no sul do Brasil e em São Paulo. Ele utilizou a técnica de reação em cadeia da polimerase (PCR) em tempo real e o resultado coletado dos dados do Genolab. De 90 indivíduos, 46,67%possuíam pelo menos uma das mutações para HH. Existe alta prevalência dessas mutações nas duas populações, portanto recomenda-se a busca em pacientes sob suspeita clínica.