RESUMO

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.

RESUMO

Phosphorus (P) is an essential mineral for the development and maintenance of the vertebrate skeletal system. Modulation of P levels is believed to influence metabolism and the physiological responses of gene expression. In this study, we investigated the influence of dietary P on skeletal deformities and osteocalcin gene expression in zebrafish (Danio rerio), and sought to determine appropriate levels in a diet. We analyzed a total of 450 zebrafish within 31 days of hatching. Animals were distributed in a completely randomized experimental design that consisted of five replications. After an eight-week experiment, fish were diaphanized to evaluate cranial and spinal bone deformities. Increases in dietary phosphorus were inversely proportional to the occurrence of partial spine fusions, the absence of spine fusions, absence of parallelism between spines, intervertebral spacing, vertebral compression, scoliosis, lordosis, ankylosis, fin caudal insertion, and craniofacial deformities. Additionally, osteocalcin expression was inversely correlated to P levels, suggesting a physiological recovery response for bone mineralization deficiency. Our data showed that dietary P concentration was a critical factor in the occurrence of zebrafish skeletal abnormalities. We concluded that 1.55% P in the diet significantly reduces the appearance of skeletal deformities and favors adequate bone mineralization through the adjustment of osteocalcin expression.

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RESUMO

O aleitamento materno é reconhecidamente um dos principais fatores de crescimento saudável, um indicador de saúde das crianças, especialmente nas populaçöes carentes. Este trabalho objetivou caracterizar a prática da amamentaçäo em um grupo de 143 mäes atendidas na Unidade Básica de Saúde Säo Lourenço (Regiäo Sul, Londrina), distribuídas em duas realidades socioeconômicas distintas. Investigou-se a frequência do aleitamento, incidência de doenças em crianças amamentadas ou näo, conhecimentos sobre o tipo ideal de leite, suplementaçäo e desmame e tabus alimentares. Observamos que a prática do aleitamento é maior entre mäes de família que ganham até um salário mínimo mensal (cerca de 64 por cento) e que receberam orientaçöes quando do parto (90 por cento); o aleitamento exclusivo até os seis meses de idade ocorre em apenas 50 por cento dos casos e o desmame é relativamente tardio, talvez devido à impossibilidade econômica em introduzir suplementaçäo adequada. Estes resultados apontam à necessidade de desencadear atividades educativas, de atençäo pré e perinatal nos serviços de saúde e lideranças comunitárias, visando a prevençäo de agravos à saúde das mäes e de seus filhos

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