Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 1 - 5 of 5
Full-Text Articles in Life Sciences
A Transgenic Marker For Newly Born Granule Cells In Dentate Gyrus, Linda S. Overstreet, Shane T. Hentges, Viviana F. Bumaschny, Flavio S.J. De Souza, James L. Smart, Andrea M. Santangelo, Malcolm J. Low, Gary L. Westbrook, Marcelo Rubinstein
A Transgenic Marker For Newly Born Granule Cells In Dentate Gyrus, Linda S. Overstreet, Shane T. Hentges, Viviana F. Bumaschny, Flavio S.J. De Souza, James L. Smart, Andrea M. Santangelo, Malcolm J. Low, Gary L. Westbrook, Marcelo Rubinstein
Faculty Publications - Department of Biological & Molecular Science
Neurogenesis in the dentate gyrus continues into adulthood, yet little is known about the function of newly born neurons or how they integrate into an existing network of mature neurons. We made transgenic mice that selectively and transiently express enhanced green fluorescent protein (EGFP) in newly born granule cells of the dentate gyrus under the transcriptional control of proopiomelanocortin (POMC) genomic sequences. Analysis of transgenic pedigrees with truncation or deletion mutations indicated that EGFP expression in the dentate gyrus required cryptic POMC promoter regions dispensable for arcuate hypothalamic or pituitary expression. Unlike arcuate neurons, dentate granule cells did not express …
Distributions Of Z-Dna And Nuclear Factor I In Human Chromosome 22: A Model For Coupled Transcriptional Regulation, P. Christoph Champ, Sandor Maurice, Jeff Vargason, Tracy Camp, P. Shing Ho
Distributions Of Z-Dna And Nuclear Factor I In Human Chromosome 22: A Model For Coupled Transcriptional Regulation, P. Christoph Champ, Sandor Maurice, Jeff Vargason, Tracy Camp, P. Shing Ho
Faculty Publications - Department of Biological & Molecular Science
An analysis of the human chromosome 22 genomic sequence shows that both Z-DNA forming regions (ZDRs) and promoter sites for nuclear factor-I (NFI) are correlated with the locations of known and predicted genes across the chromosome and accumulate around the transcriptional start sites of the known genes. Thus, the occurrence of Z-DNA across human genomic sequences mirrors that of a known eukaryotic transcription factor. In addition, 43 of the 383 fully annotated chromosomal genes have ZDRs within 2 nucleosomes upstream of strong NFIs. This suggests a distinct class of human genes that may potentially be transcriptionally regulated by a mechanism …
Take-Off Mechanics In Hummingbirds (Trochilidae), Bret W. Tobalske, Douglas L. Altshuler, Donald R. Powers
Take-Off Mechanics In Hummingbirds (Trochilidae), Bret W. Tobalske, Douglas L. Altshuler, Donald R. Powers
Faculty Publications - Department of Biological & Molecular Science
Initiating flight is challenging, and considerable effort has focused on understanding the energetics and aerodynamics of take-off for both machines and animals. For animal flight, the available evidence suggests that birds maximize their initial flight velocity using leg thrust rather than wing flapping. The smallest birds, hummingbirds (Order Apodiformes), are unique in their ability to perform sustained hovering but have proportionally small hindlimbs that could hinder generation of high leg thrust. Understanding the take-off flight of hummingbirds can provide novel insight into the take-off mechanics that will be required for micro-air vehicles. During take-off by hummingbirds, we measured hindlimb forces …
Calcium Activation Of Erk Mediated By Calmodulin Kinase I, John M. Schmitt, Gary A. Wayman, Naohito Nozaki, Thomas R. Soderling
Calcium Activation Of Erk Mediated By Calmodulin Kinase I, John M. Schmitt, Gary A. Wayman, Naohito Nozaki, Thomas R. Soderling
Faculty Publications - Department of Biological & Molecular Science
Elevated intracellular Ca2+ triggers numerous signaling pathways including protein kinases such as the calmodulin-dependent kinases (CaMKs) and the extracellular signal-regulated kinases (ERKs). In the present study we examined Ca2- dependent “cross-talk” between these two protein kinase families. Using a combination of pharmacological inhibitors and dominant- negative kinases (dnKinase), we identified a requirement for CaMKK acting through CaMKI in the stimulation of ERKs upon depolarization of the neuroblastoma cell line, NG108. Depolarization stimulated prolonged ERK and JNK activation that was blocked by the CaMKK inhibitor, STO-609; this inhibition of ERK activation by STO-609 was rescued by expression of a STO-609-insensitive mutant …
The Impact Of Social Interactions On Torpor Use In Hummingbirds, Donald R. Powers
The Impact Of Social Interactions On Torpor Use In Hummingbirds, Donald R. Powers
Faculty Publications - Department of Biological & Molecular Science
Measurements of metabolic rate and fat deposition were made on a three-species hummingbird guild in southeastern Arizona to determine if the energetic advantage gained by a dominant territorial species (Lampornis clemenciae) over subordinate competitors (Archilochus alexandri and Eugenes fulgens) resulted in less frequent use of torpor. Results showed that L. clemenciae was able to store enough fat during the day to avoid nocturnal torpor. Restricted access to food limited fat storage in both competitors, resulting in frequent torpor use. Avoidance of torpor by L. clemenciae supports the notion that use of nocturnal torpor by hummingbirds comes with a cost, and …