02990nam a2200277 a 450000100080000000500110000800800410001910000160006024500860007626001760016230000120033850000690035052020290041965000190244865000350246765000240250265300200252665300400254670000140258670000150260070000230261570000200263870000210265870000160267970000170269510092872020-01-17       2005    bl uuuu     u00u1 u    #d1 aSIMÕES, M.  aSNP identification in Schistosoma mansoni expressed genes.h[electronic resource]  aIn: X-MEETING; INTERNATIONAL CONFERENCE OF THE AB3C, 1., 2005, Caxambu. [Proceedings...]. [S.l.]: Associação Brasileira de Bioinformática e Biologia Computacionalc2005  ap. 131.  aX-meeting 2005. Presented Posters. Na publicação: Paula Kuser.  aSchistosomes are parasitic platyhelminths that cause a chronic. often debilitating disease afflicting over 200 million people worldwide. The study of genetic polymorphisms in Schistosomes is important for vaccine and drug development, in addition to the understanding of the genetic structure of populations. Single nucleotide polymorphisms (SNPs) are the most frequent form of DNA variation, they are abundant and have low mutation rates. SNPs are thought to be the next generation of genetic markers that can be used in many of important biological, genetic, pharmacological and medical applications (Thiel et al, 2004). The aim of this project is to identify in silico SNPs (Useche et al, 2001) in ESTs of Schistosoma mansoni, verify their presence in vaccine and drug target candidates and validate putative SNPs using the cathepsin B gene as a model. The S mansoni cathepin B is a proteolytic enzyme that has been evaluated for development of vaccines and new drugs. It is expressed in the parasite gut and it is believed to function in the digestion of haemoglobin, the main nutrient source for the parasite (Sajid and McKerrow, 2002.) The source of ESTs were 61.002 ESTs generated by Minas Gerais Genome Network, all with quality files base called by Phred (Ewing and Green et al, 2004). The sequences were clustered using Phrap, followed by the identification of putative SNPs applying a novel detection algorithm written by our group, cSNPer. A pre-selection of candidate sequence polymorphisms was conducted and SNPs in the cathepsin B gene, among others, were identified. The quality of the DNA sequences and individual SNPs were assessed by visual inspection with reference to chromatograms. Sixteen SNPs were identified, 44% were transitions and 56% transversions, 62% synonym mutations and 38% non-synonym mutations. The majority of the polymorphisms were in the third codon base. We are now pursuing the characterization of the possible effect of the polymorphisms in the structure of the cathepsin B protein.  aBioinformatics  aSingle nucleotide polymorphism  aSchistosoma mansoni  aBioinformática  aPolimorfismo de nucleotídeo único1 aBAHIA, D.1 aTORRES, K.1 aZERLOTINI NETO, A.1 aARTIGUENAVE, F.1 aFALCAO, P. R. K.1 aNESHICH, G.1 aOLIVEIRA, G.