This volume contains the papers selected for presentation at the 4th Brazilian Sym- sium on
Bioinformatics BSB 2009 which was held in Porto Alegre Brazil during August 29-31 2009.
The BSB symposium had its origins in the Brazilian Workshop on Bioinformatics (WOB). WOB had
three editions in 2002 (Gramado RS) in 2003 (Macaé RJ) and in 2004 (Brasília DF). The
change in the designation from wo- shop to symposium reflects the increase in the quality of
the contributions and also in the interest of the scientific community for the meeting. The
previous editions of BSB took place in São Leopoldo RS in 2005 in Angra dos Reis RJ in
2007 and in Santo André SP in 2008. As evidence of the internationalization of the event
BSB 2009 had 55 submissions from seven countries. Of the 55 papers submitted 36 were full
papers with up to 12 pages each and 19 were extended abstracts with up to 4 pages each. The
articles submitted were carefully reviewed and selected by an international Program Comm- tee
comprising three chairs and 45 members from around the world with the help of 21 additional
reviewers. The Program Committee Chairs are very thankful to the - thors of all submitted
papers and especially to the Program Committee members and the additional reviewers who
helped select the 12 full papers and the six extended abstracts that make up this book.
