Differential Expression Analysis on Schizophrenia Dataset Suggests Pseudogene RNU6-505P as under Selective Pressure

Abstract

Schizophrenia is one of the 15 leading causes of disability worldwide. About 1% of the global population has schizophrenia, with 10% of premature mortality chance. Schizophrenia is therefore associated with significant health, social and economic concerns. In this context, thalamus and striatum areas play important roles as much in schizophrenia as processing information before reaching the conscious thought: step happening soon in the creativity action. Creativity is defined by psychological scientists as the generation of ideas or products that are both original and valuable. Creativity relies on imagination and this fundamental human ability remains understudied in comparison to other important psychological phenomena. It is natural to ask whether the gene expression profiling of samples from schizophrenic patients could highlight the activity of some genes specific to humans. Microarray analysis of the dataset GSE25673 revealed that the pseudogene RNU6-505P is expressed differentially in schizophrenic samples and correlates to CYP26A1, ARHGAP18, TSPAN12, HEY2 and TMEM132A genes. Ontological analysis showed that the RNU6-505P pseudogene is involved in brain development and certain neurological pathologies. Evolutionary analysis showed that the AGA 3-nucleotide sequence of RNU6-505P has been under positive selective pressure. Finally, the 1-nucleotide mutation prediction test revealed that variations on the AGA nucleotides could be fatal to the RNA structure of the sequence. We conclude that differential expression of the RNU6-505P pseudogene can be valid to diagnose schizophrenia and the RNU6-505P pseudogene may have a relevant function in the cerebral development and in the divergent evolution of humans from apes.