ALTERNATIVE SPLICING OF THE S5A GENE DURING Schistosoma mansoni LIFE CYCLE
Pereira Júnior, O.S.1; Castro-Borges, W.1; Silva, S.H. 1; Silva, C.S. 3; Guerra-Sá, R.2; Macedo, E.1; Brigatto, O.M.1; Cabral, F. C.1; Andreolli, A.B.P.1 ; Magalhães, L.G1 ; Soares, S.C. 1; Moreira, E.B.C.1; Botelho-Machado, C. 1; Momo, P.B. 1 ; Rodrigues,V. 1.
1 Department of Biochemistry and Immunology, School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil;2 Department of Biological Science, ICEB, Federal University of Ouro Preto, MG, Brazil;3 Department of Immunology, Microbiology and Parasitology, Federal University of Uberlândia, MG, Brazil.
The 26S proteasome is a multisubunit protein-destroying. To data only a single specie of S5a (Rpn10), which function as a multiubiquitin chain-binding subunit, has been identified in invertebrate organisms. Objective: The present work aimed the analysis of the gene expression profile of S5a gene throughout life cycle of Schistosoma mansoni Material and Methods: Around three micrograms of total RNA, previously extracted with Trizol, from different life stages of this parasite (adult worms, eggs, hepatopancreas of infected and non-infected Biomphalaria snails, cercariae, schistosomulae) were submitted to a reverse transcription in the presence of an oligo dT primer and the thermoscript RT, according the manufactures. The transcript was amplified by PCR using the specific primer for S5a, designed from sequences obtained of the S. mansoni transcriptome project, ONSA-FAPESP. The PCR product was cloned and sequenced in ABI 3100. The exon-intron analyze was performed using the genomic sequence for S5a, obtained of the S. mansoni gene DB data bases (www.genedb.com). Results: The gene expression profile of the S5a subunit revealed the presence of at least three isoforms of this transcript. The adult worms, cercariae, eggs and schistosomula share a common S5a isoform containing 1260 bp. Schistosomula has a additional isoform containing 950 bp, while sporocyts has a isoform of the 1230 bp. Comparative analysis among all S5a transcripts and S5a gene revealed a presence of at least four exons and three introns in S5a genomic sequence, as well as one putative alternative splicing region into the exon two.Conclusion: This is the first time evidence of S5a isoforms generated by alternative splicing of this gene in invertebrates Supported by CNPq, FAPESP and FAEPA.
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