Dr. Bryan Dewsbury | Dewsbury Lab

Bio:
Bryan Dewsbury is an Associate Professor of Biology at Florida International University where he also is an Associate Director of the STEM Transformation Institute. He received is Bachelors degree in Biology from Morehouse College in Atlanta, GA, and his Masters and PhD in Biology from Florida International University in Miami, FL. He is the Principal Investigator of the Science Education And Society (SEAS) program, where his team conducts research on the social context of education. He is a Fellow of the John N. Gardner Institute and a Director at RIOS (Racially-Just Inclusive Open Science) institute. He conducts faculty development and support for institutions interested in transforming their educational practices pertaining to creating inclusive environments and, in this regard, has worked with over 100 institutions across North America, United Kingdom and West Africa. He is a co-author of the book 'Norton's Guide to Equity-Minded Teaching', available for free as an E-book. He is the founder of the National Science Foundation (NSF) funded Deep Teaching Residency, a national workshop aimed at supporting faculty in transforming their classroom to more meaningfully incorporate inclusive practices. He is the creator of the MOOC called 'Inclusive Teaching' sponsored by HHMI Biointeractive which will be released on August 15th. Bryan is originally from the Republic of Trinidad and Tobago and proudly still calls the twin island republic home.

Abstract:
Education holds the promise of preparing students to be engaged, thriving participants in a socially just democracy. For that ideal to occur, the structure and experience of the classroom must reflect both its constituents and consider the socially just imaginaries in which we would all like to inhabit. Using examples from the civil rights era's interrogation of our society, we will explore how an introductory biology course can help fulfill higher
education's civic mission.

Check out his book here!

Check out his HHMI/Inclusive Teaching trailer here!

Watch the seminar here!

Ned Dochtermann | Dochtermann Lab

Abstract:
While behavioral syndromes are frequently argued to represent an optimal outcome of correlated selection, they also have the potential to constrain evolutionary responses. Via intraspecific and interspecific comparisons we attempted to determine whether behavioral variation was distributed in a manner consistent with either (or both) of these explanations. We compared the distribution of genetic variation across four populations of field crickets (Gryllus integer) and for seven behavioral measures. The distribution and orientation of genetic variation was conserved across populations and divergence among populations was constrained to a shared direction in multivariate space. We then compared the distribution of behavioral variation across five species of crickets and identified a strong phylogenetic signal. Combined, these intra- and interspecific comparisons are consistent with behavioral syndromes acting as constraints on evolutionary outcomes. Finally, in a natural population of deer mice (Peromyscus maniculatus) we compared the orientation of behavioral variation with the direction of selection acting on the population. We found that the distribution of behavioral variation was inconsistent with our a priori predictions. These three independent results suggest that intuitive adaptive explanations may be insufficient to explain the ubiquity of behavioral syndromes.

Check out the seminar here!

Dr. Rafael Demarco | Demarco Lab

Bio:
I am a new Assistant Professor in the Department of Biology at the University of Louisville whose ultimate goal is to understand how changes in metabolism impact stem cell behavior during homeostasis, aging and stress conditions. I was trained as a geneticist during my Ph.D. with Dr. Erik Lundquist at the University of Kansas, where I learned to ask questions and interpret genetic data using model organisms. To pursue my objective of studying stem cells and their niches, I obtained my postdoctoral training and later position as a Research Specialist in the laboratory of Dr. Leanne Jones (first at the Salk Institute and then at the University of California, Los Angeles and San Francisco), a leading expert in the fields of stem cells and current director of the Bakar Aging Research Institute at UCSF. During my time working with Dr. Jones, I developed my own research interests focusing on how different aspects of metabolism impact the stem cell niche present in the Drosophila testis. Unexpectedly, I found that both stem cell populations present in the testis niche employ mechanisms to maintain proper lipid homeostasis in order to prevent stem cell loss. Disruptions in either mitochondrial fusion (in germline stem cells1) or autophagy (in cyst stem cells2) led to deficient lipid catabolism and ectopic accumulation of lipids in the stem cell niche, which promoted stem cell loss through differentiation. Hence, a model has emerged revealing a novel metabolic facet in the regulation of stem cell fate, which appears conserved across stem cell systems3. In my recently established laboratory, I am engaged in pursuing the mechanism(s) through which ectopic lipid accumulation can impact stem cell fate within the niche, which could shed light into the development of new strategies targeting stem cell-based regenerative therapies.

Abstract:
The capacity of stem cells to self-renew or differentiate has been attributed to distinct metabolic states. A genetic screen targeting regulators of mitochondrial dynamics revealed that mitochondrial fusion is required for male germline stem cell (GSC) maintenance in Drosophila melanogaster.  Depletion of Mitofusin (dMfn) or Optic atrophy 1 (Opa1) led to dysfunctional mitochondria, activation of Target of Rapamycin (TOR), and a dramatic accumulation of lipid droplets (LDs). Pharmacologic or genetic enhancement of lipid utilization by the mitochondria decreased LD accumulation, attenuated TOR activation and rescued GSC loss caused by inhibition of mitochondrial fusion. However, the mechanism(s) leading to GSC loss were unclear. TOR activation has been demonstrated to suppress JAK-STAT signaling by stabilizing the JAK-STAT inhibitor SOCS36E. As JAK-STAT signaling is critical for regulating stem cell self-renewal in the testis, we wanted to test the hypothesis that the increase in TOR activity in early germ cells would lead to SOCS36E stabilization, which in turn, could contribute to stem cell loss.  Indeed, we found that SOCS36E levels were higher in early germ cells upon depletion of dMfn or Opa1. Subsequently, we show that activation of the JAK-STAT pathway, but not BMP signaling, is sufficient to rescue loss of GSCs as a result of the block in mitochondrial fusion.  In addition, preliminary genetic and proximity-labeling data suggest that LD accumulation acts in parallel to TOR/SOCS36E to promote GSC loss. Our findings highlight a critical role for mitochondrial metabolism and lipid homeostasis in GSC maintenance, providing a framework for investigating the impact of metabolic diseases on stem cell function and tissue homeostasis.