Identification, in silico, of molecular targets for phenotype maintenance and muscle growth in fish

Abstract

Fish are important for food, are considered as environmental bioindicators, and can be used as models for research to try understanding human diseases. Skeletal muscle forms most of the body mass, is a source of amino acids for the body, in addition to the great importance in locomotion. Muscle growth in vertebrates occurs by hypertrophy and hyperplasia (stratified and mosaic). Fish that present muscle growth by both hyperplasias have indeterminate growth, such as pacu (Piaractus mesopotamicus), and fish that show a predominance of stratified hyperplasia, are considered as determined growth fish, such as zebrafish (Daniorerio). Although numerous studies have been carried out over the years, the mechanisms that control muscle growth are not well understood. In this sense, omics analysis is a good tool that provides a global view of genes that coordinate complex processes, such as muscle growth. Furthermore, using omics data from public banks has been an interesting strategy that can provide new information about the biological networks involved with the control of the muscle phenotype and growth, which have not been explored, yet. A meta-analysis performed by our research group, using transcriptomic data from fish skeletal muscle, showed the ribosomal gene rps27a, the cell cycle genes, cdkn1a, plan and ccnd1, as well as the eef1a2gene interactions with strong interactions in fish with different types of growth. Thus, carrying out the laboratory validation of these genes associated as ribosomal proteins in the skeletal muscle of fish with determined and indeterminate growth will be of great value in the characterization of these processes, considering that these vertebrates are exposed to the action of various extrinsic factors, such as a food restriction. The hypothesis of our work is that fish with determined growth, such as zebrafish, have a lower expression of factors related to ribosomal biogenesis when compared to fish with indeterminate growth, such as pacu, a species that has mandatory importance for the productive sector. Also, these factors can cause skeletal muscle hyperplasia and hypertrophy during fasting and re-feeding conditions. The aims of our study are: 1. Evaluate the gene expression of the rps27a, cdkn1a and pcna gene in juvenile pacus, fish of indeterminate growth, after fasting and posterior feeding, by RTq-PCR.2. Evaluate the gene expression of the same genes, in normal conditions, in fish with determined growth (zebra fish) and indeterminate growth (pacu), by RTq-PCR. 3. Explore, insilico, other genes identified through meta-analysis as potential regulators of phenotype maintenance and muscle growth, using Bioinformatics tools.(AU)