An Undergraduate Laboratory Exploring Mutational Mechanisms in Escherichia coli Based on the Luria-Delbrück Experiment.

Understanding the mechanism for DNA mutations is a key concept in most genetics and microbiology courses. In addition, understanding that most mutations occur prior to exposure to selection is an important yet often difficult concept for students to grasp. We developed an undergraduate laboratory activity on mutation mechanisms based on the classic experiment from Luria and Delbrück.

Sporulation in Bacteria: Beyond the Standard Model.

Endospore formation follows a complex, highly regulated developmental pathway that occurs in a broad range of Firmicutes. Although Bacillus subtilis has served as a powerful model system to study the morphological, biochemical, and genetic determinants of sporulation, fundamental aspects of the program remain mysterious for other genera. For example, it is entirely unknown how most lineages within the Firmicutes regulate entry into sporulation.

Diversification of a protein kinase cascade: IME-2 is involved in nonself recognition and programmed cell death in Neurospora crassa.

Kinase cascades and the modification of proteins by phosphorylation are major mechanisms for cell signaling and communication, and evolution of these signaling pathways can contribute to new developmental or environmental response pathways. The Saccharomyces cerevisiae kinase Ime2 has been well characterized for its role in meiosis. However, recent studies have revealed alternative functions for Ime2 in both S.

Meiotic regulators Ndt80 and ime2 have different roles in Saccharomyces and Neurospora.

Meiosis is a highly regulated process in eukaryotic species. The filamentous fungus Neurospora crassa has been shown to be missing homologs of a number of meiotic initiation genes conserved in Saccharomyces cerevisiae, but has three homologs of the well-characterized middle meiotic transcriptional regulator NDT80. In this study, we evaluated the role of all three NDT80 homologs in the formation of female reproductive structures, sexual development, and meiosis.