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Full-Text Articles in Life Sciences

The Role Of Hif1alpha And Hif2alpha In Muscle Development And Satellite Cell Function, Shiqi Yang Dec 2016

The Role Of Hif1alpha And Hif2alpha In Muscle Development And Satellite Cell Function, Shiqi Yang

Open Access Theses

Hypoxia inducible factors (HIFs) are central mediators of cellular responses to fluctuations of oxygen, an environmental regulator of stem cell activity. Muscle satellite cells are myogenic stem cells whose quiescence, activation, self-renewal and differentiation are influenced by microenvironment oxygen levels. However, the in vivo roles of HIFs in quiescent satellite cells and activated satellite cells (myoblasts) are poorly understood. Expression analyses indicate that HIF1α and HIF2α are preferentially expressed in pre- and post-differentiation myoblasts, respectively. Interestingly, double knockout of HIF1α and HIF2α (HIF1α/2α dKO) in embryonic myoblasts results in apparently normal muscle development and growth. However, HIF1α/2α dKO in postnatal …


Statistical Learning In Songbirds: From Self-Tutoring To Song Culture, Olga Fehér, Iva Ljubičić, Kenta Suzuki, Kazuo Okanoya, Ofer Tchernichovski Nov 2016

Statistical Learning In Songbirds: From Self-Tutoring To Song Culture, Olga Fehér, Iva Ljubičić, Kenta Suzuki, Kazuo Okanoya, Ofer Tchernichovski

Publications and Research

At the onset of vocal development, both songbirds and humans produce variable vocal babbling with broadly distributed acoustic features. Over development, these vocalizations differentiate into the well-defined, categorical signals that characterize adult vocal behaviour. A broadly distributed signal is ideal for vocal exploration, that is, for matching vocal production to the statistics of the sensory input. The developmental transition to categorical signals is a gradual process during which the vocal output becomes differentiated and stable. But does it require categorical input?We trained juvenile zebra finches with playbacks of their own developing song, produced just a few moments earlier, updated continuously …


Host-Parasite Relationships Between The Copepod Naobranchia Lizae And Its Host (Striped Mullet, Mugil Cephalus): A Description Of Morphological Development, Sara R. Teemer Jul 2016

Host-Parasite Relationships Between The Copepod Naobranchia Lizae And Its Host (Striped Mullet, Mugil Cephalus): A Description Of Morphological Development, Sara R. Teemer

DePaul Discoveries

The parasitic copepod, Naobranchia lizae, is often found within the gill arches of the striped mullet, Mugil cephalus, in the Charleston Harbor Estuarine System of South Carolina. The parasite is relatively common, but little is known about its early stages of development. In order to describe the developmental stages and pattern of morphological development, 221 female N. lizae that were collected between February 2002 and May 2003 were used. Using variation in morphological characters (maxilla, trunk), these parasites were assigned to developmental stages (juvenile, subadult, adult). A small number of the males (three ‘dwarf’ males) were also found …


The Effects Of Amphetamine Exposure On Neurodevelopment And Behavior In Early Life Stages Of Danio Rerio, Jennifer D. Bullard Jul 2016

The Effects Of Amphetamine Exposure On Neurodevelopment And Behavior In Early Life Stages Of Danio Rerio, Jennifer D. Bullard

Master of Science in Integrative Biology Theses

Amphetamines are frequently prescribed to young children for attention deficit hyperactivity disorder (ADHD). Due to the recent rise in ADHD diagnoses and the resulting increase in amphetamine intake in children, we investigated how amphetamine exposure impacts the development of stereotyped behaviors and the neural circuit that governs these behaviors. The zebrafish (Danio rerio) was used as our model organism because of the extensively studied developmental milestones these fish provide. Using escape responses as a behavior model, we exposed embryos to three doses of amphetamine (10 μg/ml, 20 μg/ml, and 30 μg/ml) environmentally during the first 48 hours of …


The Role Of Daf-19 In Non-Ciliated Neurons: How Is Neural Development Regulated By Different Daf-19 Isoforms?, Zabdiel Ek Vazquez Jun 2016

The Role Of Daf-19 In Non-Ciliated Neurons: How Is Neural Development Regulated By Different Daf-19 Isoforms?, Zabdiel Ek Vazquez

Lawrence University Honors Projects

A degenerative disease-like phenotype, specifically reduction in synaptic protein levels in adult worms, is correlated with loss-of-function of the only RFX transcription factor gene, daf-19, in C. elegans. This gene encodes four known transcription factor isoforms, two of which are correlated with particular functions. The DAF-19C isoform activates genes responsible for cilia development, while DAF-19M is needed for cilia specification in males. A comparison of the transcriptome of daf-19 null and isogenic wild type adult worms suggests both positive and negative regulation of gene expression is correlated with the presence of DAF-19 proteins. We have assessed DAF-19 regulation …


Evolvability Of The Skull: A Study Of Genetic Basis And Integration In The Teleost Craniofacial Skeleton, Yinan Hu Mar 2016

Evolvability Of The Skull: A Study Of Genetic Basis And Integration In The Teleost Craniofacial Skeleton, Yinan Hu

Doctoral Dissertations

As the field of evolutionary biology pivots away from a gene-centric view of how adaptive evolution proceeds, renewed emphasis is placed on the origin of phenotypic variation. Understanding the developmental processes that underlie the production of novel traits, and how they might influence evolvability, is considered a primary goal in the on-going “extended evolutionary synthesis”. The following dissertation explores these questions in the context of adaptive radiations in fish, with a focus on morphological variation in the craniofacial skeleton. Specifically, the first chapter investigates the genetic and developmental basis of shape (co-)variation in the feeding apparatus of African cichlid fishes, …


Further Support For Thermal Ecosystem Engineering By Wandering Albatross On Marion Island, Steven L Chown, Justine D. Shaw, Tanya M Haupt, Brent J Sinclair Feb 2016

Further Support For Thermal Ecosystem Engineering By Wandering Albatross On Marion Island, Steven L Chown, Justine D. Shaw, Tanya M Haupt, Brent J Sinclair

Biology Publications

On sub-Antarctic Marion Island, wandering albatross (Diomedea exulans) nests support high abundances of tineid moth, Pringleophaga marioni, caterpillars. Previous work proposed that the birds serve as thermal ecosystem engineers by elevating nest temperatures relative to ambient, thereby promoting growth and survival of the caterpillars. However, only 17 days of temperature data were presented previously, despite year-long nest occupation by birds. Previous sampling was also restricted to old and recently failed nests, though nests from which chicks have recently fledged are key to understanding how the engineering effect is realized. Here we build on previous work by providing nest temperature data …


Characterization Of Somatically-Eliminated Genes During Development Of The Sea Lamprey (Petromyzon Marinus), Stephanie A. Bryant Jan 2016

Characterization Of Somatically-Eliminated Genes During Development Of The Sea Lamprey (Petromyzon Marinus), Stephanie A. Bryant

Theses and Dissertations--Biology

The sea lamprey (Petromyzon marinus) undergoes programmed genome rearrangements (PGRs) during early development that facilitate the elimination of ~20% of the genome from the somatic cell lineage, resulting in distinct somatic and germline genomes. To improve our understanding of the evolutionary/developmental logic of PGR, we generated computational predictions to identify candidate germline-specific genes within a transcriptomic dataset derived from adult germline and the embryonic stages encompassing PGR. Validation studies identified 44 germline-specific genes and characterized patterns of transcription and DNA loss during early embryogenesis. Expression analyses reveal that several of these genes are differentially expressed during early embryogenesis …


Weighing The Relative Potential Impacts Of Climate Change And Land-Use Change On An Endangered Bird, Betsy A. Bancroft, Joshua J. Lawler, Nathan H. Schumaker Jan 2016

Weighing The Relative Potential Impacts Of Climate Change And Land-Use Change On An Endangered Bird, Betsy A. Bancroft, Joshua J. Lawler, Nathan H. Schumaker

Biology Faculty Scholarship

Climate change and land-use change are projected to be the two greatest drivers of biodiversity loss over the coming century. Land-use change has resulted in extensive habitat loss for many species. Likewise, climate change has affected many species resulting in range shifts, changes in phenology, and altered interactions. We used a spatially explicit, individual-based model to explore the effects of land-use change and climate change on a population of the endangered Red-cockaded Woodpecker (RCW; Picoides borealis). We modeled the effects of land-use change using multiple scenarios representing different spatial arrangements of new training areas for troops across Fort Benning. …