In trypanosomatids, mature mRNAs are generated after two processing events: trans-splicing to add the spliced leader sequence to the 59 end of transcripts and subsequent polyadenylation. A genome-wide analysis comparing the SL addition site along the developmental cycle of the parasite Catharanthine sulfate suggests that alternative trans-splicing plays an important role in differential gene expression. The occurrence of alternative trans-splicing could be an explanation for the presence of so many different isoforms in T. cruzi after radiation response. A similar event has already been described in D. radiodurans, since different isoforms of the single-strand binding protein were produced after ionizing radiation stress induction. SSB proteins are vital for cell survival due to their involvement in processes such as DNA replication, recombination, and repair. The SSB protein spots in the gel followed a dynamic pattern of appearance, indicating a progressive processing of the C-terminal acidic tail, perhaps upon its interaction with ssDNA. The observed isoelectric point and molecular weight of deinococcal SSB isoforms were in agreement with the in silico-predicted pI and molecular weight of the SSB proteins shortened from the Cterminal end. Intriguingly, in most of the observed processed proteins, the Aceclidine hydrochloride identified peptide sequences were the same or nearly the same in all sequenced protein spots and, therefore, it was impossible to define the actual outcome of the protein processing. As a particular case of study, the protein annotated as prostaglandin F2 alpha synthase, which is similar to NADH-flavinoxidoreductase, is processed to a total of six different forms. While the expected molecular weight for the annotated sequence is of 42 kDa, only two isoforms are nearly this size and were, in fact, the most downregulated isoforms. A third isoform has a predicted molecular mass of 68 kDa, greatly exceeding the expected protein size. As all of the MS/MS-identified peptides were mapped to the C-terminal portion of the isoforms, there is no information to characterize the N-terminal of this enlarged protein naturally present in the NI parasites and downregulated after exposure to gamma radiation.