TRANSCRIPTIONAL CHARACTERIZATION OF RIBOTOXINS HORIZONTALLY ACQUIRED IN Trialeurodes vaporarorium

CAÑADAS GUADALUPA; LAPADULA WALTER JESÚS; JURI AYUB, MAXIMILIANO

Congreso; XL Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

Ribosome Inactivating Proteins (RIPs) are RNA N-glycosidase that depurinate a specific adenine residue in the conserved sarcin/ricin loop of 28S rRNA. RIP encoding genes are found in plant, bacterial and fungal lineages. Recently, we reported the presence of these genes in some species of mosquitos and whiteflies belonging to Culicidae and Aleyrodidae families, respectively. Evolutionary analysis confirmed that both groups of genes were acquired by two independent horizontal gene transfer events and are evolving under purifying (negative) selection. This evidence indicates that these foreign genes have a positive impact on the fitness of the host organism. Recently, we have demonstrated that RIP genes present in A. aegypti are expressed and their transcripts are polyadenylated. Most importantly, the expression levels of RIP genes are modulated across the developmental stage of mosquito. Based on these results, we hypothesized that RIP genes have a functional role in insects. In order to test this postulate, we performed a transcriptional characterization of RIP genes in one species of Aleyrodidae family. For this purpose, we established a colony of whiteflies, confirmed its taxonomic identity by DNA barcoding sequencing, and quantified the transcript levels of RIP genes by RT-qPCR. As result of this work, we found that the colony’s individuals belong to T. vaporarorium. Moreover, we experimentally confirmed the presence of three RIP genes in the genome of this species. Interestingly, two of the three RIP genes were expressed and their transcription levels are modulated during ontogeny. In conclusion, we showed evidence of expression for these foreign genes in a second lineage of insects. Similar to A. aegypti, these results suggest that RIP genes are functional in Aleyrodidae family, supporting the main hypothesis of this work.