Spring 2009 Seminar Abstracts

Monday, February 2, 2009
Dr. Jiming Jiang, University of Wisconsin
Title: Structure and evolution of eukaryotic centromeres: A rice model
Abstract: The centromere serves as the chromosomal site for assembly of the proteinaceous kinetochore to which spindle microtubules attach during cell division. Centromeric chromatin is unique because it contains a special histone H3 variant (CENH3). In most muticellular eukaryotes, the CENH3-containing chromatin is embedded megabase-sized arrays of satellite repeats. However, several rice centromeres are largely associated with non-satellite DNA, providing an excellent model to study centromere structure and evolution. Various types of DNA sequences, including genes, were found within the CENH3-associated chromatin in rice. The "centromeric genes" are transcriptionally competent and show similar histone modification profiles compared to genes located outside of the centromeres. Rice centromeres structurally resemble human neocentromeres, which are new centromeres emerged from non-centromeric regions. Our results support the hypothesis that all eukaryotic centromeres were evolved from neocentromeres.

Monday, February 16, 2009
Dr. Homme Hellinga, Duke University
Title: Engineering Biology
Abstract: Engineering biology requires learning how to systematically manipulate components and systems to construct organisms with new functions. Sophisticated computational design techniques are being developed in conjunction with robotic automation methods to engineer proteins with a wide variety of new properties. I will use the engineering of proteins for the detection of molecules to illustrate these principles, and will show how such proteins can be used as diagnostic materials in medicine or can be integrated as components in biological systems to enable bacteria or plants to function as sentinels that detect pollutants and chemical threats.

Monday, March 9, 2009
Dr. Michael Marsiske, University of Florida
Title: Producing short- and long-term change in late life cognition
Abstract: A growing body of intervention research seeks to improve cognitive function in older adults, often through training and practice interventions. In assessing such changes, it is important to first understand the normal steady-state fluctuation and practice-related cognitive gains that older adults may experience on their own. This presentation will consider three broad sets of results: (1) Intra-individual variability and inconsistency in cognition: Descriptive and predictive findings; (2) Practice-related gain in cognition: What can older adults achieve on their own?; and (3) Interventions for late life cognition: Magnitude, durability and breadth of training effects.