Genetics and Genomics Commons^™

Elucidation Of The Role Of Agouti-Signaling Protein Throughout Folliculogenesis And Early Embryonic Development In Cattle, Heather L. Chaney

Graduate Theses, Dissertations, and Problem Reports

The oocyte expresses certain genes during folliculogenesis to regulate the acquisition of oocyte competence. Oocyte competence, which refers to the presence of imperative molecular factors in the oocyte that are critical for high oocyte quality, is directly related to the ability of the oocyte to result in a successful pregnancy following fertilization. Over the past few decades, the development and optimization of assisted reproductive technologies, particularly in vitrofertilization, have enabled the beef and dairy industries to advance cattle genetics and productivity. However, only approximately 40% of bovine embryos will develop to the blastocyst stage in vitro. In addition, bovine embryos …

The Investigation Of Novel Bovine Oocyte-Specific Long Non-Coding Rnas And Their Roles In Oocyte Maturation And Early Embryonic Development, Jaelyn Zoe Current

Graduate Theses, Dissertations, and Problem Reports

Early embryonic loss is a significant factor in livestock species' infertility, resulting in an economic deficit. In cattle, the in vivo fertilization rate is ~90%, with an average calving rate of about 55%, indicating an embryonic-fetal mortality rate of roughly 35%. Further, 70-80% of total embryonic loss in cattle occurs during the first three weeks after insemination, particularly between days 7-16. Growing evidence indicates that the oocyte plays an active role in regulating critical aspects of the reproductive process required for successful fertilization, embryo development, and pregnancy. However, defining oocyte quality remains enigmatic. Recently, many have abandoned the notion that …

Genetic Underpinnings Of Novel Trait Development In A Euwallacea-Fusarium Mutualism, Elaina J. Spahr

Graduate Theses, Dissertations, and Problem Reports

Evolutionary Developmental Biology seeks to answer fundamental questions about the mechanisms underlying the evolution and innovation towards increasing structural complexity within the body plan. The ambrosia symbiosis, a polyphyletic group of xylem-feeding beetles, provides a wealth of diversity in novel pouch-like structures called mycangia. This diversity could serve as a rich model for understanding how mutualisms may prompt structural innovation and diversification in a host organism. The ambrosia symbiosis has become a fast-growing research subject in entomology and forest pathology but has yet to experience the same attention under the lens of evolutionary developmental genetics.

Development of mycangia was examined …

Getting To The Root Cause: The Genetic Underpinnings Of Root System Architecture And Rhizodeposition In Sorghum, Farren Smith

Graduate Theses, Dissertations, and Problem Reports

Plants are some of the most diverse organisms on earth, consisting of more than 350,000 different species. To understand the underlying processes that contributed to plant diversification, it is fundamental to identify the genetic and genomic components that facilitated various adaptations over evolutionary history. Most studies to date have focused on the underlying controls of above-ground traits such as grain and vegetation; however, little is known about the “hidden half” of plants. Root systems comprise half of the total plant structure and provide vital functions such as anchorage, resource acquisition, and storage of energy reserves. The execution of these key …

The Origin Of Novel Trait Inferred From Transcriptomic Analysis And A Targeted Gene Approach In The Beetle Horns., Naureen Fatima

Graduate Theses, Dissertations, and Problem Reports

The origin of the evolutionary new trait (evolutionary novelty) and its subsequent evolution is of great interest for biologists in various fields, and beetle horns have been used to address this fundamental biological question. Previous studies on one of the horned beetle species, Onthophagus taurus, that utilized comparative gene expression analyses, suggested legs to be a strong candidate of the origin of horns. At the same time, their horns are secondary sexual traits whose development is regulated by the same gene (doublesex) as genitalia, which also originates from paired appendages such as legs. However, little is known …

Developmental Mechanisms For The Diversification Of Polyphenic Morphs In The Head Horn Of Onthophagine Beetles (Coleoptera: Scarabaeidae Onthophagus Taurus): Plasticity Through Nutrition, Logan Paul Zeigler

Graduate Theses, Dissertations, and Problem Reports

Developmental plasticity is the phenotypic variation between organisms that is caused by environmental interactions affecting the developmental systems of organisms. The research focused primarily on nutrition-responsive developmental plasticity. In this research we used the nutritionally determined head horn development of Onthophagus taurus to better understand the developmental mechanisms and genetic underpinnings of nutrition-responsive trait development. We focused specifically on altering the availability of specific nutrition-related primary metabolites, cholesterol and palmitic acid, identified in the activity of The Hedgehog pathway, a critical pathway in head horn development. By altering diet composition using cholesterol, reducing transcript expression of an acyltransferase gene, rasp …

The Effects Of Internal Physiology On Polyphenic Horn Development In The Dung Beetle Onthophagus Taurus, Naomi Garrett Williamson

Graduate Theses, Dissertations, and Problem Reports

An organism’s phenotype can be affected in development by alterations to gene expression based on environmental inputs. Nutrition is one such environmental input and the central regulator of development of large horn or small horn phenotypes in the dung beetle species, Onthophagus taurus. However, little is known about the nature of chemical compounds that are critical to this plastic horn development. To better understand these compounds, we are utilizing an untargeted metabolomic approach as well as a targeted gene approach. Through the metabolomic approach, it was uncovered that environmental conditions tend to have a greater impact on metabolomic composition …