1. Molecular Forensics
Adapting a Case for Two
Different Course Levels

2. Molecular Forensics

3. Case Summary
 This case is based on a true story
 HIV+ dentist in Florida was accused of
infecting several patients
 HIV sequences were obtained for the dentist
and the patients
 The dentist was sued based on the sequence
evidence

4. Goals
 Introduce Bioinformatics to students using case-
based learning
 Suggest methods for upper level undergraduate
course, e.g. molecular genetics (300), and lower
level course such as microbiology (200)
 Demonstrate to students that science is evolving
and tools are evolving…science is not static

5. Steps for learning
 Introduce the case: Molecular Forensics
 Look at the “printed” data: HIV sequence data
 Explore the difficulties of manually comparing sequences
 Explore options
 Introduce Workbench
 Align sequences
 Pairwise sequence similarities
 Rooted and unrooted trees

6. Steps for learning – cont.
(In preparation: Module to show students how to
interpret trees)
 Use module with students to explore how to
interpret trees
 Analyze the case using new skills and come to a
conclusion

7. Tree Module - Overview
 Explanation of phylogenetic trees
 What do they show?
 What don’t they tell you?
 Are there different types of trees? Why?
 Sample trees
 Correlating taxonomy with trees
 Practice in interpreting

8. Tree Module
Written Introduction to Trees
Possible Resources
Phylogenetic Trees
Susan Cates
This work is produced by The Connexions Project and
licensed under the Creative Commons Attribution License
http://cnx.org/content/m11052/2.8/
Comparing Phylogenetic Trees
Module by: sam donovan
This work is produced by The Connexions Project and
licensed under the Creative Commons Attribution License
http://cnx.org/content/m15807/latest/

9. Sample Trees
 Provide students with rRNA sequence data
from a variety of organisms, e.g. –
 Rabbit, frog, fungus and bacteria
 Provide rooted and unrooted trees based on
this data
 Show students corresponding alignment

10. Sample Trees

11. Clustal W
Unrooted Tree
http://Workbench.sdsc.edu

12. Clustal W
Rooted Tree
http://Workbench.sdsc.edu

13. Clustal W
Sequence Alignment
http://Workbench.sdsc.edu

14. Taking the Case Farther
 Higher level courses..300 level and higher
 Compare the HIV from the “dentist forensics”
case with HIV sequences from other studies
 Look at trees and interpret

15. Taking the Case Further
 Lower level courses: 200 level and below
 Take the rooted and/or unrooted trees produced
from the case data and create a mobile which
shows the relationships between samples