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Lessons

Generating Multiple Sequence Alignments with ClustalW

Dr. Susan Parrish (McDaniel College) developed a basic lecture and weblem exercise (found at the end of the lecture) on using ClustalW to generate multiple sequence alignments, phylograms, and cladograms. This lecture and exercise are given prior to beginning the GEP annotation projects. Students who submit their GEP annotation projects early are then asked to generate multiple sequence alignments and phylograms of the putative proteins encoded within their assigned contig or fosmid, compared to those related proteins encoded by other Drosophila species of interest to the GEP.

Generating Multiple Sequence Alignments with Clustal Omega

Developed by Dr. Susan Parrish (McDaniel College), this PowerPoint presentation describes how Clustal Omega can be used to produce multiple sequence alignments. The multiple sequence alignments of the nucleotide sequences surrounding the transcription start sites can be used to identify core promoter motifs, while the multiple sequence alignments of protein sequences can be used to identify conserved domains. The presentation also includes a discussion of two strategies (UPGMA and Neighbor Joining) that are often used to construct phylogenetic trees.

Overview of Multiple Sequence Alignment Algorithms

Developed by Yu He (TA for Bio 4342), this PowerPoint presentation provides a basic overview of the common algorithms used to generate multiple sequence alignments. The presentation also illustrates how one could use Clustal Omega to generate a multiple sequence alignment for a set of orthologous proteins in order to identify conserved domains within the protein.

Using FlyBase RNA-Seq Tools to Investigate Gene Expression Profiles

This walkthrough illustrates how GBrowse and the RNA-Seq tools at FlyBase can be used to identify genes with similar expression patterns. This walkthrough provides an introduction to the TopoView RNA-Seq track in FlyBase GBrowse, the FlyBase Expression Profile Search tool, and the Expression Similarity Search tool. It also illustrates how the Gene2Function web site can be used to infer the function of a D. melanogaster gene based on the functions of its orthologs in other model organisms.

Eukaryotic Comparative Genomics

This lecture from Dr. Barak Cohen discusses the major factors to consider (e.g., species to analyze, model for conserved sequences) when using phylogenetic footprinting to identify conserved regions across multiple species. The lecture also illustrates how the weight matrix model can be used to describe sequence motifs, and it provides an introduction to Magma, which uses the multiple species with multiple genes approach to discover conserved motifs.

From Smith-Waterman to BLAST

This lecture from Dr. Jeremy Buhler discusses the limitations of the Smith-Waterman local alignment algorithm and the heuristics used by the BLAST program in order to reduce the search space and to quickly produce high-scoring local alignments.

Introduction to Dynamic Programming

Developed by Dr. Anton E. Weisstein (Truman State University) and Mingchao Xie (TA for Bio 4342), this lecture and exercise introduce students to the core algorithm (dynamic programming) used by many sequence alignment tools (e.g., BLAST). The exercise includes a spreadsheet with a dynamic programming matrix that allows students to explore the impact of different types of alignments (i.e. global, semiglobal, and local) and scoring systems on the resulting sequence alignment.

An Introduction to Hidden Markov Models

Developed by Dr. Anton E. Weisstein (Truman State University), Zongtai Qi and Zane Goodwin (TAs for Bio 4342), this curriculum introduces students to the idea of Hidden Markov Models (HMM) that forms the core component of most gene predictors. The lecture by Zongtai Qi uses weather prediction to illustrate the key concepts of the HMM, whereas the lecture by Zane Goodwin focuses on the HMM that models a splice donor site. The exercise developed by Dr. Weisstein includes a spreadsheet with a simple HMM exercise that models a splice donor site. The spreadsheet allows students to examine the impact of different transition and emission probabilities on splice site predictions. A video recording of Dr. Weisstein’s HMM presentation during the 2014 GEP Alumni Workshop is also available online. This HMM curriculum is also available on CourseSource.

Web Databases for Drosophila

This PowerPoint presentation introduces the species-specific databases available on the web, including FlyBase and the Ensembl Drosophila melanogaster database.