Differentially expressed genes and miRNA identification in pig skeletal muscle / Identificação de genes diferencialmente expressos e miRNAs em músculo esquelético de suínos

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

25/07/2011

RESUMO

The pig (Sus scrofa) is considered an important animal for meat production. This interest revolves around the potential for muscle growth, which usually is associated with certain characteristics during prenatal myogenesis. To study the genes responsible for these characteristics, expressed sequence tags (EST) provide direct information about the transcriptome and indirectly on the relationship between the genome and different phenotypes, supplying knowledge about differentially expressed genes (DEG) as well as other transcribed genomic sequences for the control of gene expression, e.g., some non-coding RNAs. Characteristics of muscle tissue in pigs may have been directly influenced by genes, and those being regulated, for example, by miRNAs, in different stages of development. This study aimed to identify by in silico annotation, DEG and non-coding sequences, focusing on miRNAs, using cDNA libraries constructed from semi-membranous skeletal muscle of three different pig breeds (Duroc, Large White and naturalized Brazilian Piau ) as well as analysis of gene expression profiles of identified genes and miRNAs during seven stages of development (21, 40, 70 and 90 days prenatal and 107, 121 and 171 days postnatal) from commercial line animals Longissimus Dorsi muscle. Twenty-one identified genes out of 34 DEGs belongs to the muscle-specific path. From these, 13 genes had their expression profiles analyzed by qRT-PCR during the seven periods, forming four clusters of similar expression, with one having greater expression in the postnatal period and three in the prenatal. In the analysis of non-coding sequences, an important result was the identification of two new miRNAs in pigs, which had their sequences similar to mature miRNAs hsa-miR-1207- 5p and hsa-miR-665 which had their precursor sequences forming secondary structures and classified as real precursor sequence by MiPred program. From these, we found 289 genes and 214 respectively regulated by them, of which four are muscle-specific. The new miRNAs and other three which have been identified in previous studies in pigs had their expression levels analyzed by quantitative real time PCR during the mentioned seven periods. Their levels of expression differed between pre-and postnatal stages. These studies may provide valuable information allowing a better understanding of the molecular mechanisms involved in muscle development. Analyses of DEG in the pre-and postnatal periods suggest the presence of genes acting specifically on certain stages of muscle development, contributing to better explain their functions. The identification of two new miRNAs, together with other previously identified and posted on the databases in pigs, may contribute to a better understanding of gene regulation and is important for studies of genetics and animal breeding, allowing the understanding of the muscle deposition physiology to meat production in pigs.

ASSUNTO(S)

tag seqüência expressa in silico pré-natal qrt-pcr mirna músculo esquelético expressão genetica e melhoramento dos animais domesticos expressed sequence tag in silico prenatal qrt-pcr mirna skeletal muscle expression

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