Pathways over Time

Clare O'Connorclare.oconnor@bc.eduBoston College

Project Location

A Functional Genomics Project for the Introductory Laboratory

Student Audience

Introductory, Major

Scientific Domain

  • Genetics/Genomics
  • Molecular and cellular biology

Nature of the Research

  • Wet lab/bench research
  • Informatics/computational research
  • Basic research

Core Concepts

  • Evolution: The diversity of life evolved over time by process of mutation, selection, and genetic change.
  • Information Flow and Exchange: The growth and behavior of organisms are activated through the expression of genetic information in context.
  • Pathways and Transformation of Energy: Biological systems grow and change by processes based on chemical transformation pathways and are governed by the laws of thermodynamics.

Core Competencies

  • Applying the process of science
  • Using quantitative reasoning
  • Tapping into the interdisciplinary nature of science
  • Communicating and collaborating

Learning Objectives

  • Students become proficient in using basic microbiological and molecular biology techniques.
  • Students appreciate how enzymes evolve to suit the metabolic requirements of an organism.
  • Students become proficient in the scientific process by designing and conducting original experiments and by analyzing experimental results.
  • Students become proficient in searching and collecting information from the scientific literature and genomic databases.
  • Students learn to communicate their experimental results in both oral and written formats for multiple kinds of audiences.


BI 204 introduces students to basic techniques in molecular cell biology, genetics and bioinformatics within the context of a functional genomics project. Student are studying the evolution of genes involved in methionine biosynthesis, using the budding yeast, Saccharomyces cerevisiae, as the point of reference. The methionine biosynthetic pathway has been chosen for this project, because it involves multiple enzymatic steps, each of which can be studied by a group of 2-3 students. S. cerevisiae has been chosen as the reference point because it is a well-studied model organism that is easily cultured by undergraduate students at low cost and because of the extensive online and clone resources available to researchers.

During the first part of the semester, students learn to distinguish between S. cerevisiae mutant strains by replica plating, colony PCR and plasmid complementation. In the second part of the semester, students determine if deficiencies in S. cerevisiae mutants can be rescued by expression of an ortholog from a phylogenetically distant organism. Students use bioinformatics tools to identify orthologs of the S. cerevisiae MET genes. Students then transform S. cerevisiae with expression plasmids carrying the orthologous sequences and monitor complementation. Students then use western blots to monitor expression of over-expressed proteins. In the 2011-2012 academic year, students are studying the functional conservation of MET genes between S. cerevisiae and the fission yeast, Schizosaccharomyces pombe. These two yeast species diverged from a common ancestor between 300 million and 1 billion years ago.

O'Connor, Clare Boston College