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Full-Text Articles in Life Sciences

Investigating The Role Of Lbh During Early Embryonic Development In Xenopus Laevis, Emma Weir Oct 2019

Investigating The Role Of Lbh During Early Embryonic Development In Xenopus Laevis, Emma Weir

Masters Theses

LBH is a highly conserved protein whose role during vertebrate development is relatively under-studied. In collaboration with the Albertson lab, our lab has previously shown that it is necessary for cranial neural crest cell migration in the zebrafish and in Xenopus laevis. The molecular mechanisms through which it acts are not well understood.

In Xenopus, LBH is a maternally deposited protein. As such, studying its role in early development has not been feasible through the morpholino-mediated knockdown techniques that prevent translation of target genes. Recently, a technique for degrading endogenous proteins was developed, called Trim-Away. This was developed in mammalian ...


Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel Oct 2019

Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel

Masters Theses

In order to ascertain the degree of compatibility in developmental restructuring and behavioral plasticity between two fish species frequently made subject of laboratory research (Metriaclima zebra & Danio rerio), alternative trophic niche exposure experiments utilizing novel three-prong feeding treatments were conducted to obtain morphometric data, which demonstrated both species do bear some degree of plasticity. The results are somewhat complicated by differences in locality of detectable restructuring, which may be due to disparity in the form-function relationship for each species’ lineage. Each is notable in the manner of respective species’ jaw protrusion, as it is driven by anterior kinethmoid rotation in ...


Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho Nov 2018

Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho

Doctoral Dissertations

Mammalian development involves remarkable changes, starting from a single-cell, totipotent zygote and ending with a developed organism comprised of diverse cells types with distinct morphologies, structures, and functions. Within three days of murine development, the two parental genomes merge into a single nucleus, begin zygotic gene expression, undergo epigenetic remodeling, and make the first lineage decisions. Diversity in cell-types is possible even though cells share the same genome. This diversity is achieved by the tight regulation of differential transcriptional programs. There are many ways these transcriptional programs can be initiated. Epigenetic alterations to the genome can drive transcriptional changes.

Epigenetic ...


New Approaches In Engineering Somatic Embryogenesis In Loblolly Pine Suspension Cultures, Elizabeth Morgan Cummings Bende Jul 2018

New Approaches In Engineering Somatic Embryogenesis In Loblolly Pine Suspension Cultures, Elizabeth Morgan Cummings Bende

Doctoral Dissertations

Many industries including agriculture and healthcare require efficient methods for replication of plants with optimal traits. The loblolly pine (Pinus taeda) is a valuable crop in the timber industry, occupying 30 million acres of U.S. land, and breeding efforts aim to produce a crop with ideal phenotypic traits, including superior growth and wood quality. One method to large-scale clonal crop propagation is somatic embryogenesis (SE), the process through which asexual (somatic) plant cells undergo differentiation in vitro, resulting in germination-competent embryos. There are three main stages of growth and development that lead to the production of embryos: 1) aggregated ...


Identification Of The Mesoderm/Endoderm Interactions Involved In Murine Liver And Pancreas Development, Jesse Angelo Jul 2018

Identification Of The Mesoderm/Endoderm Interactions Involved In Murine Liver And Pancreas Development, Jesse Angelo

Doctoral Dissertations

The definitive endoderm, one of the three primary germ layers, arises during gastrulation as a simple epithelial sheet that will produce the entire gut tube and associated organs including the thyroid, lung, liver and pancreas. DiI fate mapping and whole embryo culture were used to determine the endodermal origin of the 9.5 days post coitum (dpc) dorsal and ventral pancreas buds. Our results demonstrate that the progenitors of each bud occupy distinct endodermal territories. Similarly, previous data has shown that the neighboring liver is formed from two separate progenitor populations. Numerous studies have demonstrated that signals secreted from adjacent ...


Partial Craniofacial Cartilage Rescue In Ace/Fgf8 Mutants From Compensatory Signaling From The Ventricle Of Danio Rerio, Douglas A. Calenda Ii Oct 2017

Partial Craniofacial Cartilage Rescue In Ace/Fgf8 Mutants From Compensatory Signaling From The Ventricle Of Danio Rerio, Douglas A. Calenda Ii

Masters Theses

Examples of asymmetric organs are found throughout the animal kingdom. Whether it is superficial like the fiddler crab’s claw or within an organism like our visceral organs, asymmetries have repeatedly evolved in nature. However, the genetic and developmental origins for asymmetric organ development remain unclear, especially for superficially paired structures. Within zebrafish, a striking example of asymmetry occurs within the ace/fgf8 mutant. The pharyngeal cartilages of these mutants develop asymmetrically 35% of the time, with more cartilages developing on the left or right side of the head, but the origins of this asymmetry are unknown. A significant proportion ...


Methylglyoxal Influences Development Of Caenorhabditis Elegans Via Heterochronic Pathway, Jiaying Wang Jul 2017

Methylglyoxal Influences Development Of Caenorhabditis Elegans Via Heterochronic Pathway, Jiaying Wang

Masters Theses

Methylglyoxal is a highly reactive dicarbonyl compound, which is widely distributed in food products and beverages, and is particularly high in Manuka honey. In addition to its antibacterial effects, methylglyoxal is also known as a major precursor of advanced glycation end products (AGEs), that produces altered macromolecules (such as proteins and DNA), leading to abnormal physiological changes. However, the effects of methylglyoxal on development is unclear. Thus, this study aimed to determine the role of methylglyoxal in this aspect using Caenorhabditis elegans (C. elegans). Treatment of methylglyoxal at 0.1 mM and 1 mM for 48 h significantly inhibited development ...


A Genetic Analysis Of Cichlid Scale Morphology, Kenta C. Kawasaki Nov 2016

A Genetic Analysis Of Cichlid Scale Morphology, Kenta C. Kawasaki

Masters Theses

Epidermal appendages are found on every vertebrate this world has to offer. In fish, these are commonly represented by scales. While we have a solid grasp of how scales develop, little is known about the underlying genetic mechanisms behind these phenotypic changes. Using two species of African cichlids (Labeotropheus fuelleborni and Tropheops “red cheek”) with varying scale phenotypes, we sought to examine their F2 hybrid offspring and statistically link the responsible genetic elements to their respective parental phenotypes through Quantitative Loci Trait (QTL) analysis.

Scales were removed from six different locations across the midline of each individual. Then, numerous traits ...


Mammalian Egg Activation: The Roles Of Trpv3 Channels And Plcz1, Hoi Chang Lee Mar 2016

Mammalian Egg Activation: The Roles Of Trpv3 Channels And Plcz1, Hoi Chang Lee

Doctoral Dissertations

Calcium channels at the plasma membrane have been suggested to mediate Ca2+ influx during egg activation. The transient receptor potential (TRP) Ca2+ channel, TRPV3, is differentially expressed in oocytes during maturation, being fully active at MII stage. Specific stimulation of TRPV3 channels in mouse eggs promotes Ca2+ influx sufficient to induce egg activation and parthenogenesis. In chapter 2, we explore the function and distribution dynamics of the TRPV3 channel protein during oocyte maturation. Using dsRNA, TrpV3 overexpression, and inhibitors of protein synthesis, we modified the native expression of the channel and showed that the TRPV3 protein is ...


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 ...


Characterization Of The Role Of Intrinsic And Extrinsic Factors During Murine Endoderm Development, Siyeon Rhee Nov 2015

Characterization Of The Role Of Intrinsic And Extrinsic Factors During Murine Endoderm Development, Siyeon Rhee

Doctoral Dissertations

Yin Yang1 (YY1) is a ubiquitously expressed factor that plays multiple roles in early mouse development. We have found that an essential role of YY1 in the visceral endoderm (VE) of the yolk sac is the maintenance of VEGF. Furthermore, we have demonstrated that paracrine signals downstream of VEGF support the VE, assessed by maintenance of HNF4α. Because the VE is essential for yolk sac development, and thus for embryonic survival, we used an inducible-knockout strategy to demonstrate that YY1 is essential in the definitive endoderm (DE) for invasion of hepatoblasts into the surrounding mesenchyme. By E14.5 YY1-/- livers ...


Uncovering New Roles For The Cell Surface Protease Adam13 In Neural Crest Migration, Genevieve Abbruzzese Nov 2015

Uncovering New Roles For The Cell Surface Protease Adam13 In Neural Crest Migration, Genevieve Abbruzzese

Doctoral Dissertations

ADAMs are a family of transmembrane metalloproteases that control cell behavior by cleaving both cell adhesion and signaling molecules. They play a variety of roles in diverse tissue types during development and can affect cell processes such as migration, differentiation, growth and survival. In the embryo, several ADAMs have proven to be integral components of the cranial of neural crest (CNC), which is a multipotent population of cells that gives rise to multiple structures of the face and head. These cells are highly motile and undergo a large-scale migration throughout the embryo that is essential for proper craniofacial development. The ...


Behavioral And Neural Mechanisms Of Impulsive Choice, Jesse Mcclure Nov 2015

Behavioral And Neural Mechanisms Of Impulsive Choice, Jesse Mcclure

Doctoral Dissertations

Impulsive choice is defined as the preference for a small immediate reward over a larger delayed reward. Individual variablity in impulsive choice correlates with many socially relevant behaviors. Although forms of impulsive choice have been studied in both behavioral ecology and psychology, the exchange of knowledge between these fields is just beginning. Drawing from both of these fields will improve our research methods allowing for a more detailed understanding of this complex behavior. Existing tasks to measure impulsive choice conflate the delay and quantity of the reward. To address this, I have drawn from foraging research to establish a method ...


Interactions Between The Hypothalamic-Pituitary-Adrenal (Hpa) Axis, Oxytocin System, And Behavior In Differently Reared Rhesus Monkeys (Macaca Mulatta), Amanda F. Hamel Aug 2015

Interactions Between The Hypothalamic-Pituitary-Adrenal (Hpa) Axis, Oxytocin System, And Behavior In Differently Reared Rhesus Monkeys (Macaca Mulatta), Amanda F. Hamel

Doctoral Dissertations

Adverse experiences that occur during early critical periods of development modify activity of neuroendocrine systems, such as the hypothalamic-pituitary-adrenal (HPA) axis and oxytocin system. This dissertation examines the effects of nursery rearing, an established model of adverse early experiences, on activity of the HPA axis and oxytocin system in infant and adult rhesus macaques (Macaca mulatta). In addition, influence of oxytocin system activity on the HPA axis and behavioral reactivity was examined. In infant monkeys, nursery-rearing was associated with lower HPA axis, yet higher oxytocin system activity, following the acute stress of developmental assessment. Nursery rearing may result in dysregulation ...


The Role Of The Novel Lupus Antigen, Acheron, In Moderating Life And Death Decisions, Ankur Sheel Aug 2014

The Role Of The Novel Lupus Antigen, Acheron, In Moderating Life And Death Decisions, Ankur Sheel

Masters Theses

Programmed cell death (PCD) is a major regulatory mechanism employed during development and homeostasis. The term PCD was coined to describe the death of the intersegmental muscles (ISMs) of moths at the end of metamorphosis. The timing of ISM death in the Tobacco Hawkmoth, Manduca sexta, is regulated by a fall in the titer of the steroid molting hormone 20-hydroxyecdysone (20E) late on day 17of pupal-adult development. This triggers the release of the peptide hormone, Eclosion Hormone (EH), which mediates its effects via the secondary messenger cGMP. It has been previously demonstrated that ISM death requires de novo gene expression ...