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Full-Text Articles in Life Sciences

Reducing Seed Coat Fiber Content And Pod Shatter, And Engineering Medium Chain Fatty Acids-Containing Oil, In The Oilseed Crop Pennycress ( Thlaspi Arvense L. ), Maliheh Esfahanian Mar 2021

Reducing Seed Coat Fiber Content And Pod Shatter, And Engineering Medium Chain Fatty Acids-Containing Oil, In The Oilseed Crop Pennycress ( Thlaspi Arvense L. ), Maliheh Esfahanian

Theses and Dissertations

The overall goal of this thesis was to genetically improve agronomic traits of pennycress (Thlaspi arvense L.; Field Pennycress) and demonstrate the production of value-added designer seed oils to domesticate pennycress and enable its establishment as a new winter annual oilseed/meal/cover crop to be grown in temperate regions of the world. In the U.S. Midwest, pennycress can be double cropped on existing farmland during the time between corn harvest and subsequent planting of soybeans the following spring. Pennycress has the potential to produce 2,000 lbs/acre seeds, which at 33% by weight oil content and 20% protein, would yield 85 gallons/acre …


A Molecular Toolset For The In Vivo Detection Of A Sulfolobus Islandicus Leucyl Trna Synthetase Paralog, Nicholas Michael Bretz Dec 2020

A Molecular Toolset For The In Vivo Detection Of A Sulfolobus Islandicus Leucyl Trna Synthetase Paralog, Nicholas Michael Bretz

Theses and Dissertations

An ancient and ubiquitous set of enzymes known as the aminoacyl-tRNA synthetases are required for the viability of all organisms. The aminoacyl-tRNA synthetases catalyze the attachment of amino acids onto tRNA molecules. The aminoacylated, or charged, tRNA is then transported and utilized at the ribosome for the synthesis of proteins. The genome of the hyperthermophilic microorganism Sulfolobus islandicus (S. islandicus) harbors a unique leucyl-tRNA synthetase paralog, LeuRS-I, of unknown function. While its duplicate, LeuRS-F, carries out all the classical functions of LeuRS-family enzymes, LeuRS-I fails to charge leucine onto tRNALeu, despite its ability to activate this amino acid and bind …


An Investigation Of Gene Regulatory Network State Space Variability, Sara Faye Liesman Jul 2020

An Investigation Of Gene Regulatory Network State Space Variability, Sara Faye Liesman

Theses and Dissertations

Genes are segments of DNA that provide a blueprint for cells and organisms to effectively control processes and regulations within individuals. There have been many attempts to quantify these processes, as a greater understanding of how genes operate could have large impacts on both personalized and precision medicine. Gene interactions are of particular interest, however, current biological methods can not easily reveal the details of these interactions. Therefore, we infer networks of interactions from gene expression data which we call a gene regulatory network, or GRN. Due to the robust behavior of genes and the inherent variability within interactions, models …


Elucidating The Role Of The High Aliphatic Glucosinolate ( Hag ) Genes In Pennycress ( Thlaspi Arvense L. ) Glucosinolate Production, Dalton Williams May 2020

Elucidating The Role Of The High Aliphatic Glucosinolate ( Hag ) Genes In Pennycress ( Thlaspi Arvense L. ) Glucosinolate Production, Dalton Williams

Theses and Dissertations

Pennycress (Thlaspi arvense L.) is a Brassica species being developed into an oilseed-producing winter cash cover crop. Similar to its relatives, rapeseed (Brassica napus L.) and camelina (Camelina sativa L.), pennycress seeds produce high levels of oil and protein (~34% oil and ~19% protein dry weight). For pennycress to be economically viable and environmentally sustainable as a crop, both the oil and seed meal must be utilized. Pennycress like other Brassicaceae, produces high levels of glucosinolates in the seed coat. Glucosinolates taste bitter and can be metabolized by the enzyme, myrosinase, into toxic isothiocyanates, nitriles, and epithionitriles. Seed meal containing …


Developing Pennycress ( Thlaspi Arvense ) As A Biodiesel Feedstock Crop And Plant Model System, Michaela Mcginn Feb 2018

Developing Pennycress ( Thlaspi Arvense ) As A Biodiesel Feedstock Crop And Plant Model System, Michaela Mcginn

Theses and Dissertations

Thlapsi arvense L. (pennycress) is currently being developed as a profitable oilseed-producing winter annual cover crop with extreme cold tolerance and a rapid life cycle that can be grown on fallow farmland throughout the U.S. Midwest Corn Belt, controlling soil erosion and nutrient runoff while serving as an additional source of income for the American farmer without displacing food crops. The research comprising this dissertation demonstrates that pennycress can serve as a user-friendly model system highly similar to Arabidopsis thaliana, and is well-suited for both laboratory and field experimentation, being readily employable in existing growth facilities. After 10 generations of …


Elucidating The Molecular Parameters And Mechanism Of Homology Searching During Meiosis In Neurospora Crassa, Nicholas Adam Rhoades Jul 2017

Elucidating The Molecular Parameters And Mechanism Of Homology Searching During Meiosis In Neurospora Crassa, Nicholas Adam Rhoades

Theses and Dissertations

Integration of foreign DNA into a host genome is often detrimental to the host organism, as the DNA is often of viral or transposon origin. Many organisms have established DNA surveillance and genome integrity mechanisms to defend against these harmful DNA insertions. Neurospora crassa, a filamentous fungus belonging to the Ascomycota group, has several DNA defense mechanisms to combat foreign DNA integration to its genome. One such mechanism is Meiotic Silencing of Unpaired DNA (MSUD). During meiosis, this remarkable system can detect unpaired genes on homologous chromosomes during sexual reproduction and silence their expression throughout meiosis. In order for the …


Investigating The Roles And Interactions Of Sad-6 Within The Parameters Of Meiotic Silencing By Unpaired Dna ( Msud )., Zachary J. Smith Mar 2016

Investigating The Roles And Interactions Of Sad-6 Within The Parameters Of Meiotic Silencing By Unpaired Dna ( Msud )., Zachary J. Smith

Theses and Dissertations

Meiotic silencing by unpaired DNA (MSUD) is a process observed in the model organism Neurospora crassa. During this process unpaired DNA between homologous chromosomes is detected and silenced, resulting in the suppression of unpaired genes. The effects of MSUD can be seen using phenotypic markers such as the Roundspore gene and evidence supports the existence of a physical search for unpaired DNA. However, the mechanism for detecting unpaired DNA remains uncertain. Previously, we have shown evidence that a Rad54-like protein, SAD-6 is required for the efficient completion of MSUD and may be necessary for the detection of unpaired DNA. Currently, …


Cell Wall Mutants In Arabidopsis Thaliana, Christy Jane Moore Jun 2015

Cell Wall Mutants In Arabidopsis Thaliana, Christy Jane Moore

Theses and Dissertations

Plant cell walls are versatile structures, playing important roles in communication, defense, organization and support. The importance of each of these functions varies by cell type, with specialized cells often utilizing one or two functions more than others. Trichomes, or leaf hairs, and hypocotyl cells for instance, exhibit distinct cell wall characteristics. Trichomes have developed very thick cell walls with several raised structures, known as papillae, on their surfaces. It is believed that these cells function in defense against predators, making it difficult to crawl on the leaf surface, and in protection against ultra violet radiation, through refraction of light …


Investigating The Initial Detection Stage Of Meiotic Silencing By Unpaired Dna In The Model Organism Neurospora Crassa, Pegan A. Sauls Apr 2015

Investigating The Initial Detection Stage Of Meiotic Silencing By Unpaired Dna In The Model Organism Neurospora Crassa, Pegan A. Sauls

Theses and Dissertations

In an attempt to neutralize transposable elements or retrovirus invasions Neurospora crassa will rely on one of its many genome defense mechanism, Meiotic Silencing by Unpaired DNA (MSUD). MSUD works in a two-step process that first detects unpaired sequences between homologous chromosomes followed by downstream silenced expression of the sequence. The ultimate silencing stage of MSUD is widely accepted to operate through an RNAi-like system. However, the mechanics of the detection step of MSUD remains elusive. The research presented attempts to elaborate on how the initial stage of MSUD occurs and its specifics. First, a genetic approach is utilized to …


Genetic Analysis Of Ton2 Dependent Processes In Microtubule Organization In Arabidopsis Thaliana, Samantha Nicole Atkinson Oct 2014

Genetic Analysis Of Ton2 Dependent Processes In Microtubule Organization In Arabidopsis Thaliana, Samantha Nicole Atkinson

Theses and Dissertations

Microtubules carry out many functions within the cell. They're used during mitosis and meiosis to move chromosomes to opposite sides of the cell so that cell division can occur. They're also used as structural support for the cell and are involved in establishing the cell shape. Microtubules are also able to reorient from a longitudinal orientation to a transverse orientation in response to gibberellic acid and auxin (two hormones that are involved in cell elongation). The mechanism for how this reorientation occurs is unknown. The TONNEAU2 (TON2) protein is necessary for proper microtubule organization. We looked at how TON2 affects …