From Structure Prediction to Genomic Screens for Novel Non-Coding RNAs

Non-coding RNAs (ncRNAs) are receiving more and more attention not only as an abundant class of genes, but also as regulatory structural elements (some located in mRNAs). A key feature of RNA function is its structure. Computational methods were developed early for folding and prediction of RNA structure with the aim of assisting in functional analysis. With the discovery of more and more ncRNAs, it has become clear that a large fraction of these are highly structured. Interestingly, a large part of the structure is comprised of regular Watson-Crick and GU wobble base pairs. This and the increased amount of available genomes have made it possible to employ structure-based methods for genomic screens. The field has moved from folding prediction of single sequences to computational screens for ncRNAs in genomic sequence using the RNA structure as the main characteristic feature. Whereas early methods focused on energy-directed folding of single sequences, comparative analysis based on structure preserving changes of base pairs has been efficient in improving accuracy, and today this constitutes a key component in genomic screens. Here, we cover the basic principles of RNA folding and touch upon some of the concepts in current methods that have been applied in genomic screens for de novo RNA structures in searches for novel ncRNA genes and regulatory RNA structure on mRNAs. We discuss the strengths and weaknesses of the different strategies and how they can complement each other

A exposição ao chumbo como fator de risco para alterações no desenvolvimento da linguagem Lead exposure as a risk factor for alterations in language development

OBJETIVO: Verificar a ocorrência de alterações no desenvolvimento, em particular, o desenvolvimento da linguagem, em crianças com histórico de exposição ao metal chumbo, e a existência ou não de correlação entre índice de contaminação e desenvolvimento de linguagem. MÉTODOS: Cinqüenta e oito crianças entre 12 e 36 meses foram submetidas à triagem fonoaudiológica; destas, 15 compareceram para avaliação específica por meio da Escala de Desenvolvimento Comportamental de Gesell e Amatruda por terem falhado na triagem. A correlação entre índice de chumbo e o grau de defasagem na linguagem foi verificada. RESULTADOS: Seis crianças apresentaram defasagem na área da linguagem da Escala, sendo que, uma delas apresentou defasagem em todos os campos. CONCLUSÃO: Não foi encontrada correlação negativa significante entre a concentração de chumbo e o grau de defasagem no desenvolvimento de linguagem dos indivíduos participantes, entretanto, o estudo sugere que a contaminação pelo chumbo tornou-se fator de risco para alterações no desenvolvimento da linguagem destas crianças. Dessa forma, mais estudos são necessários para verificar o grau de prejuízo que este metal pode ocasionar às pessoas, principalmente quando estão em desenvolvimento.<br>PURPOSE: To verify the occurrence of alterations in the development, in particular language development, in children with history of metal lead exposure, and whether there is a correlation between index of contamination and language development. METHODS: Fifty eight children with ages between 12 and 36 months were submitted to speech-language pathology screening; 15 of these children failed the screening, and were referred to specific evaluation using the Behavioral Development Scale by Gesell and Amatruda (Escala de Desenvolvimento Comportamental de Gesell e Amatruda). The correlation between lead index and the degree of language deficits was verified. RESULTS: Six children presented deficits in the scale's language items; one of them had deficits in all items. CONCLUSION: No significant correlation was found between lead concentration and the degree of the language deficits of the subjects, however, the study suggests that lead contamination became a risk factor for deficits in language development. Therefore, further studies are necessary to verify the damages that this metal can cause in people exposed to it, especially when they are in development