Sep 6

Welkin Pope, Ph.D., University of Pittsburgh
Cluster J Mycobacteriophages and the discovery of self-splicing introns in phage structural proteins (hosted by Steve Cresawn)

Sep 13

Michael S. Strickland, Ph.D., Department of Biological Sciences, Virginia Tech
"Microbial communities and the terrestrial carbon cycle: What are the connections?"

Abstract: Microbial communities are the primary drivers of the terrestrial carbon cycle but our understanding of this role is limited. My research seeks to explore how change in microbial communities can ultimately impact processes related to the carbon cycle. I will be presenting research that examines this relationship and that spans topics from restoration and applied ecology to diversity-ecosystem function relationships. Together, demonstrating that the smallest organisms in an ecosystem are often some of the most important.

Sep 20

Grace Wyngaard, Ph.D Biology & Brain Walton, Ph.D. Mathematics & Statistics, JMU
"Billions of Basepairs of Recently Expanded, Repetitive Sequences are Eliminated from the Somatic Genome during Copepod Development"

Abstract: We present the first in-depth genomic analysis of chromatin diminution (i.e. the programmed excision of DNA from the pre-somatic cell lineage during embryogenesis) from a copepod. Copepods are unique among the taxa that undergo chromatin diminution because they have evolved massive germline genomes; depending on species, germline genome sizes range from 15 – 75 Gb, 12-74 Gb of which are lost from pre-somatic cell lineages at germline – soma differentiation. Although numerous functions for chromatin diminution have been proposed across taxa, very little is known about the DNA excised from copepods, precluding any understanding of (1) the processes underlying germline genome expansion, and (2) the function of chromatin diminution.

We used high-throughput genomic shotgun data and qPCR to characterize the germline and somatic genomes of Mesocyclops edax.  We show that the majority of both M. edax genomes consists of repetitive sequences that are either 1) verifiable transposable elements (TEs), or 2) non-simple elements of likely TE origin. Our results suggest that germline genome expansion in M. edax reflects explosive proliferation of repeat elements, and that billions of base pairs of such repeats are deleted from the somatic genome every generation. Thus, we hypothesize that chromatin diminution is a mechanism that controls repeat element load, and that this load can evolve to be divergent between tissue types within single organisms.

9/27

 10/4

 John Fuller, Ph.D. Postdoctoral Fellow, Wilmer Eye Institute, Johns Hopkins School of Medicine, Guest Researcher, Assay Development & Screening Technologies, NIH NCATS.
"Drug Screening in Academia: a search for treatments of a rare disease"

 There are currently no NIH approved drugs for treating diseases that result in photoreceptor death (e.g. retinitis pigmentosa, AMD). By modifying and microscaling assays that utilize automated microscopy and quantitative gene expression analysis, we are capable of testing thousands of drugs simultaneously over multiple concentrations, enabling dose-response profiling for promising lead molecules that may influence photoreceptor survival.

 10/11

 Stephen Turner, Ph.D. University of Virginia & JMU Alumnus

 10/18

 Dan N. Cox, Ph.D. Krasnow Institute for Advanced Study, George Mason University
Systems Neuroscience Driven Exploration of Dendrite Development and Behavior

 The functional diversity of neurons in complex nervous systems is matched by the corresponding diversity of dendrite arbor morphologies. The shape of a mature arbor delineates propagation and integration of dendritic signals, hence defining the computational properties of the neuron. Moreover, dendrite morphology underlies synaptic connectivity and thus heavily affects network dynamics and functions as well as behavior in response to a range of sensory stimuli.  This functional role is further illustrated in a diverse array of neuropathological and neurodegenerative disease states including Alzheimer’s, mental retardation, and Autism in which strong neuroanatomical correlates exist between dendrite defects and cognitive impairments.  We use a systems-level approach to identify and characterize key molecular and cellular programs that function in directing cell-type specific dendrite morphogenesis and on uncovering structure-function links between dendrite development and somatosensory behavior with an emphasis on pain perception.

 10/25

Catherine Lowry Franssen, Ph.D. Psychology, JMU
From Mommy Brains to Airplanes: Impacts of Environmental Enrichment on Neuroendocrinology

 Throughout life, experiences and environments shape behavior through altering an organism’s physiology. The experience of becoming a parent changes neural structures in the adult brain, accompanying –and likely underlying- the acquisition of parental behavior. As another example, spending time in an enriched environment changes not only neural structures and behaviors related to cognition, but can also alter an animal’s anxiety response. These discoveries lead us to ask which environments and experiences are best for improving cognition and reducing stress? Some answers may come in unconventional places.

 11/1

Jessica Lucas, Ph.D. Biology Department, Santa Clara University

 11/8

Tom Voss, Ph.D., SRI
Cell-based and Animal Models of Acute Human Viral Infections - Building Tools for Drug and Vaccine Development