Life Sciences Commons^™

Synchronization Of Reproduction In Deertoe Mussel (Truncilla Truncata), Kendell R. Loyd

MSU Graduate Theses

Freshwater mussels, Order Unionoida, are diverse and widespread in North America but have suffered general decline and many extinctions in recent decades. The reproductive biology of Unionoida is complex and may be vulnerable to human impacts. Male mussels release aggregates of sperm called spermatozeugmata that drift downstream. Females obtain spermatozeugmata from the water and brood the fertilized eggs internally during development. Many aspects of general reproductive biology are poorly understood, including the mechanisms that coordinate spawning and the route by which sperm meet eggs in the female. The present study focuses on reproduction in the Deertoe (Truncilla truncata), …

Multigeneration Effects Of Chronic Exposure To Polycyclic Aromatic Hydrocarbons In Gulf Killifish (Fundulus Grandis), Andrea Yammine

LSU Master's Theses

The goal of this study was to examine potential adaptation within two generations of Gulf killifish exposed to polycyclic aromatic hydrocarbons (PAH) while also investigating the use of mucus as an effective and non-lethal alternative to determine concentrations of 11-ketotestosterone (11-KT) and vitellogenin (VTG) of F. grandis. Multiple biomarkers were used to assess adaptation within these fish, such as lysozyme (enzyme critical in innate immunity), and 11-ketotestosterone and vitellogenin (endocrine hormones often affected by PAHs).

Mucal concentrations of 11-KT and VTG were determined and evaluated for effectiveness through comparative assays with blood plasma. This method was then applied to …

Great Basin Bristlecone Pine Resistance To Mountain Pine Beetle: An Evaluation Of Dendroctonus Ponderosae Host Selection Behavior And Reproductive Success In Pinus Longaeva, Erika L. Eidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (Dendroctonus ponderosae) is a native bark beetle that attacks and kills most species of pines (Pinus) throughout its range in western North America. Due to the strong relationship between thermal conditions and mountain pine beetle population success, climate change-induced changes in mountain pine beetle outbreaks are a major concern for land managers. Over the past several decades, warmer than average temperatures allowed mountain pine beetle populations to reach epidemic levels across much of the western U.S. and Canada, including high elevations where outbreaks were previously limited by cool temperatures. Many high-elevation pine …

Assessing The Rate And Extent Of Transgenerational Acclimation And Adaptation To Ocean Warming, Abby C. Nease

HCNSO Student Theses and Dissertations

A primary goal of climate change research is to determine if species will be able to persist in a warmer environment. Most studies predict climate change will cause many species to become extinct. However, these predictions are based on experiments where only a single life stage or generation of a species was exposed to predicted future conditions (i.e. shock treatments), and thus overlook the possibility of species adapting or acclimatizing to new environmental conditions over multiple generations. As a result, current projections of species persistence through climate change are likely to overestimate species extinction. In this study, the rate and …

Determining The Reproductive Patterns Of The Titan Acorn Barnacle (Megabalanus Coccopoma) In Its Introduced Range, Isabel L. Moran Ms.

Honors College Theses

Invasive species are a significant conservation concern given their contribution to native species decline. The barnacle, Megabalanus coccopoma, is a common invasive species in tropical and subtropical regions of both the Pacific and Atlantic oceans. Little is known about the life history and ecology of M. coccopoma, and data on reproductive biology could provide valuable insight into its propensity to establish introduced populations. Most species of barnacle (including M. coccopoma) are hermaphroditic, but self-fertilization is rare in species studied to date. A recent genetic study of introduced M. coccopoma populations in the southeastern US showed high levels of …

Glucocorticoids And Parental Effort In Tree Swallows (Tachycineta Bicolor), Mackenzie Prichard

Undergraduate Theses, Professional Papers, and Capstone Artifacts

All vertebrates respond to stressful situations through the release of hormones called glucocorticoids (CORT). These hormones alter processes within the body to prioritize long term survival over immediate reproduction. It is hypothesized that this is helps individuals survive until conditions become more favorable for successful reproduction. Historically, stress was hypothesized to primarily to pull organisms out of reproductive life history stages when unfavorable conditions made offspring survival slim (otherwise known as the “CORT-tradeoff hypothesis”). However, recent evidence suggests that birds actively feeding nestlings show elevated CORT levels, possibly due to the increased metabolic demands of parenthood. This relationship has been …

Local And Systemic Actions Of Gnrh Relating To Estradiol And Associated Reproductive Parameters In Beef Cattle, Jerica J.J. Rich

Electronic Theses and Dissertations

In cattle, estradiol is responsible for modulating many mechanisms involved in successful reproduction. Specifically estradiol is the primary signal for the initiation of standing estrus (Allrich, 1994), and cattle expressing estrus prior to fixed time AI (FTAI) have been reported to have increased preovulatory estradiol concentrations (Perry and Perry, 2008) and increased pregnancy success compared to animals that did not exhibit estrus (Richardson et al., 2016). Gonadotropin releasing hormone, classically, stimulates estradiol production via the two-cell two-gonadotropin hypothesis (Fortune and Quirk, 1988), and GnRH administered systemically in small doses (5 μg) has been reported to elicit an LH pulse similar …

Evaluation Of A Role For Prolactin In The Recrudescense Of Ovarian Activity In Seasonally Anovulatory Mares, Erin Lea Oberhaus

LSU Doctoral Dissertations

A series of experiments studied the possible role for prolactin in the spring-time recrudescence of ovarian activity in mares. The first experiment was based on cabergoline administration to seasonally anovulatory mares to prevent the seasonal rise in endogenous plasma prolactin to assess whether reduced prolactin altered onset of ovarian activity or first ovulation. Although prolactin concentrations were reduced, basal prolactin concentrations recovered from suppression by the time of the next injection (10 days later), even though low-dose sulpiride stimulation of prolactin was still suppressed by 85%. The subsequent experiment tested whether season affected the duration and degree of suppression produced …

Characterizing The Developmental And Reproductive Toxicities Of Cannabidiol And Δ9-Tetrahydrocannabinol, Dennis Ray Carty

Electronic Theses and Dissertations

Medical marijuana is legal in twenty-nine of the United States and an additional nineteen states have passed legislation for cannabidiol (CBD) treatment of drug-resistant epilepsy, such as Dravet Syndrome (DS) which is diagnosed in children as young as two months. While CBD has shown anecdotal and recently clinical trial efficacy in reducing seizure frequency in DS patients, little is known about the potential adverse side-effects on child physiology, brain development, adult disease, or subsequent generations. Moreover, CBD is rarely administered without including low concentrations of Δ9-tetrahydrocannabinol (THC). The goal of this project is to characterize the relative morphological, behavioral, reproductive, …

Managing Sociality Of A Captive Female Bornean Orangutan From Breeding To Post-Partum At The Smithsonian's National Zoo, Marie Vergamini

Theses and Dissertations

The Association of Zoos and Aquariums’ Orangutan Species Survival Plan® aims to maintain 100 Bornean orangutans (Pongo pygmaeus) in captivity. Because investment in breeding these lineages is high, properly managing sociality of potential mothers is essential. This study assessed how behaviors of a captive breeding female at the Smithsonian’s National Zoo changed from pre-gestation through the offspring’s sixth month of age to improve breeding recommendations.

The infant Bornean orangutan was born September 2016. Results indicate that during breeding, the mother socialized most with two adult females. During pregnancy, the pregnant female socialized in less energy-consuming ways, i.e. grooming. …