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7. Analyze the following ten DNA sequences by the Gibbs sampling algorithm.
seq1   C CAG A
seq2   G TTA A
seq3   G TAC C
seq4   T TAT T
seq5   C AGA T
seq6   T TTT G
seq7   A TAC T
seq8   C TAT G
seq9   A GCT C
seq10  G TAG A
  1. Assuming that the background base frequencies are 0.25, calculate a log odds matrix for the central three positions.
  2. Assuming that another sequence G TTT G is the left-out sequence, slide the log odds matrix along the left-out sequence and find the log odds score at each of three possible positions.
  3. Change each log odds score to an odds score and sum the odds scores. Calculate the probability of a match at each position in the left-out sequence. (Odds score = 2 raised to the power of the log odds score.)
  4. How do we choose a possible location for the motif in the left-out sequence?


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