Poster abstracts
Poster number 5 submitted by Abhijit Badve
Evolutionary dynamics of RNA binding proteins expressions in mammalian species
Abhijit S. Badve (Department of Bio-Health Informatics, School of Informatics, IUPUI,Indinapolis), Vishal K. Sarsani (Department of Bio-Health Informatics, School of Informatics, IUPUI,Indinapolis), Yaseswini Neelamraju (Department of Bio-Health Informatics, School of Informatics, IUPUI,Indinapolis), Sarath C. Janga (Department of Bio-Health Informatics, School of Informatics, IUPUI,Indinapolis)
Abstract:
RNA binding proteins (RBPs) play important roles in controlling the post-transcriptional fate of RNA molecules, yet their evolutionary dynamics remains largely unknown. As expression profiles of genes encoding for RBPs can yield insights about their evolutionary trajectories on the post-transcriptional regulatory networks across species, we performed a comparative analyses of RBP expression profiles across 8 tissues (brain, cerebellum, heart, lung, liver, lung, skeletal muscle, testis) in 7 mammals (human, chimpanzee, gorilla, orangutan, macaque, rat, mouse). Noticeably, orthologous gene expression profiles suggest a significantly higher expression level for RBPs than their non-RBP gene counterparts - which include other protein-coding and non-coding genes, across all the mammalian tissues studied here. This trend is significant irrespective of the tissue and species being compared, though RBP gene expression distribution patterns were found to be generally diverse in nature. Our analysis also shows that RBPs are expressed at a significantly lower level in human and mouse tissues compared to their expression levels in equivalent tissues in other mammals chimpanzee, orangutan, rat, etc. which are all likely exposed to diverse natural habitats and ecological settings compared to more stable ecological environment humans and mice might have been exposed, thus reducing the need for complex and extensive post-transcriptional control. Further analysis of the similarity of orthologous RBP expression profiles between all pairs of tissue-mammal combinations clearly showed the grouping of RBP expression profiles across tissues in a given mammal, in contrast to the clustering of expression profiles for non-RBPs, which frequently grouped equivalent tissues across diverse mammalian species to group together, suggesting a significant evolution of RBP expression after speciation events. Calculation of species specificity indices for RBPs across various tissues, to identify those that exhibited restricted expression to few mammals, revealed that about 30% of the RBPs are species-specific in at least one tissue studied here.
References:
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Keywords: RBP expression, evolution, mammalian species