DNA1: Last week's take-home lessons

10/8/02


Click here to start


Table of Contents

DNA1: Last week's take-home lessons

DNA2: Today's story and goals

DNA 2

Applications of Dynamic Programming

Alignments & Scores

Increasingly complex (accurate) searches

"Hardness" of (multi-) sequence alignment

Testing search & classification algorithms

Comparisons of homology scores

Switch to protein searches when possible

A Multiple Alignment of Immunoglobulins

Scoring matrix based on large set of distantly related blocks: Blosum62

Scoring Functions and Alignments

Calculating Alignment Scores

DNA2: Today's story and goals

What is dynamic programming?

Recursion of Optimal Global Alignments

Recursion of Optimal Local Alignments

Computing Row-by-Row

Traceback Optimal Global Alignment

Local and Global Alignments

Time and Space Complexity of Computing Alignments

Time and Space Problems

Time & Space Improvement for w-band Global Alignments

Summary

DNA2: Today's story and goals

A Multiple Alignment of Immunoglobulins

A multiple alignment <=> Dynamic programming on a hyperlattice

Multiple Alignment vs Pairwise Alignment

Computing a Node on Hyperlattice

Challenges of Optimal Multiple Alignments

Methods and Heuristics for Optimal Multiple Alignments

ClustalW: Progressive Multiple Alignment

Star Alignments

DNA2: Today's story and goals

Accurately finding genes & their edges

Annotated "Protein" Sizes in Yeast & Mycoplasma

Predicting small proteins (ORFs)

Small coding regions

Motif Matrices

Protein starts

Motif Matrices

DNA2: Today's story and goals

Why probabilistic models in sequence analysis?

A Basic idea

Sequence recognition

Database search

Plausible sources of mono, di, tri, & tetra- nucleotide biases

CpG Island + in a ocean of - First order Markov Model

Estimate transistion probabilities -- an example

Estimated transistion probabilities from 48 "known" islands

Viterbi: dynamic programming for HMM

DNA2: Today's story and goals

Author: George Church

Home Page: http://www.courses.fas.harvard.edu/~bphys101/