Identification of a conserved baculoviral microRNA coded by Spodoptera frugiperda Multiple Nucleopolyhedrovirus

SANTIAGO MANUEL GOMEZ BERGNA; PIDRE MATÍAS LUIS; FERRELLI MARÍA LETICIA

evento virtual

Congreso; 2nd Women in Bioinformatics & Data Science LA Conference; 2021

Women in Bioinformatics & Data Science LA

Spodoptera frugiperda Multiple Nucleopolyhedrovirus (SfMNPV) belongs to theAlphabaculovirus genus, Baculoviridae. Its natural host is Spodoptera frugiperda, anagronomically important pest.MicroRNAs (miRNA) are endogenous eukaryotic small noncoding RNAs that regulate geneexpression by kidnapping or cleaving mRNAs in a sequence specific manner. SeveralmiRNAs were found and well characterized in viruses, including baculoviruses.The aim of this work was to identify a miRNA encoded in the SfMNPV genome, ortholog tothe previously described and experimentally validated BmNPV-miR-2 encoded in Bombyxmori nucleopolyhedrovirus (BmNPV) genome. BmNPV-miR-2 is coded in the complementstrand of the chi-a gene, which encodes the chitinase protein.Initially, we used the Matcher algorithm to perform a local alignment between BmNPV-miR-2sequence and the complement strand of the chitinase gene of SfMNPV. It generated analignment with 81 % identity, matching a sequence similar in location to the site whereBmNPV-miR-2 is encoded in BmNPV.Next, using the miRNAFold webserver, we looked for putative sequences that could acquirethe characteristic stem-loop structure and that included the sequence found in the alignment.We found a sequence of 81 nucleotides that generated a secondary structure with aminimum free energy (MFE) of -23,24 kcal/mol.In order to validate the conservation, we performed a blastn search with the pre-miRNAsequence obtained from miRNAFold as a query. We found highly conserved sequences inmore than 25 different baculovirus species, including BmNPV. Finally, we looked for putative viral targets using the miRanda algorithm, in the galaxywebserver. It predicted 34 possible targets, expressed mostly in late and very late stages ofthe infection.In conclusion, we found a novel miRNA in SfMNPV, ortholog to BmNPV-miR-2 andpotentially capable of regulating gene expression of multiple putative targets.