Characterizing alternative splicing as a generator of lncRNAs from coding genes.

RODRÍGUEZ, FLORENCIA S.; SERVI, LUCAS; BELLORA, NICOLÁS; PETRILLO, EZEQUIEL

Congreso; SAIB-SAMIGE Reunión Conjunta (LVII SAIB Meeting - XVI SAMIGE Meeting); 2021

SAIB

Light signals induce a massive reprogramming of gene expression in plants. Alternative splicing (AS) produces multipletranscripts (variants or isoforms) from a single gene through the variable and regulated choice of different splicing sites. Inaddition to generating different isoforms that can be translated into different proteins, this process can also give rise to variantswithout coding capacity, which tend to degrade, allowing delicate regulation of the amount of protein generated. However,non-coding transcripts could control chromatin status, modulate the abundance of other RNAs (miRNAs, lncRNAs, mRNAs,etc.), and even translation. So, they could act as long non-coding RNAs (lncRNAs). Light regulates the alternative splicing oftranscripts of different genes in A. thaliana, among which At-RS31. Changes in the splicing pattern of this gene in response tolight would modify the amount of protein that can be generated (splicing factor), since only one isoform is translatable,mRNA1. Although the overexpression of mRNA1 generates deleterious phenotypes, by overexpressing all the variants(genomic construction), the resulting plants present normal phenotypes. We previously demonstrated that the otherpredominant isoform of At-RS31, mRNA3, is retained in the nucleus, progressively accumulating in the dark. These findingsinvited us to hypothesize that this transcript could be fulfilling a nuclear regulatory function, being an lncRNA generated byalternative splicing. This reasoning led to the bioinformatics search for other potential transcripts showing similarcharacteristics. For this, the differential expression of the isoforms of A. thaliana in multiple RNAseq (from public repositories)linked to the translation, degradation and localization of RNA was analyzed. As a result of this analysis, we found multiplenew candidates, which resemble the At-RS31 mRNA3 and could function as lncRNAs in A. thaliana. Next we will validatesome of the candidates and characterize their functions.