Transcriptional and post-transcriptional regulation of young genes in plants

• Published in: BMC biology Vol. 20; no. 1; pp. 134 - 7
• Main Authors: Raxwal, Vivek Kumar, Singh, Somya, Agarwal, Manu, Riha, Karel
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 09.06.2022; BioMed Central; BMC
• Subjects: Abiotic stress; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Botanical research; Cell cycle; Chromatin; Chromatin - genetics; Chromatin - metabolism; Deoxyribonucleic acid; DNA; Enhancers; Evolutionary capacitance; Gene expression; Gene Expression Regulation, Plant; Gene regulation; Genes; Genetic regulation; Genetic transcription; Genomes; Homology; Insects; Nematodes; Nonsense-mediated RNA decay; Open chromatin; Orphan genes; Oryza - genetics; Oryza - metabolism; Plant genetics; Plants - metabolism; Post-transcription; Proteins; Transcription Initiation Site; Young genes; India; Nonsense-mediated RNA decay; Open chromatin; Evolutionary capacitance; Orphan genes; Young genes; Abiotic stress
• ISSN: 1741-7007; 1741-7007
• DOI: 10.1186/s12915-022-01339-7

New genes continuously emerge from non-coding DNA or by diverging from existing genes, but most of them are rapidly lost and only a few become fixed within the population. We hypothesized that young genes are subject to transcriptional and post-transcriptional regulation to limit their expression and minimize their exposure to purifying selection. We performed a protein-based homology search across the tree of life to determine the evolutionary age of protein-coding genes present in the rice genome. We found that young genes in rice have relatively low expression levels, which can be attributed to distal enhancers, and closed chromatin conformation at their transcription start sites (TSS). The chromatin in TSS regions can be re-modeled in response to abiotic stress, indicating conditional expression of young genes. Furthermore, transcripts of young genes in Arabidopsis tend to be targeted by nonsense-mediated RNA decay, presenting another layer of regulation limiting their expression. These data suggest that transcriptional and post-transcriptional mechanisms contribute to the conditional expression of young genes, which may alleviate purging selection while providing an opportunity for phenotypic exposure and functionalization.