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Full-Text Articles in Life Sciences

Sex And Starvation Influences Latrotoxin Expression In The Brown Widow Spider, Mattie Harris Apr 2022

Sex And Starvation Influences Latrotoxin Expression In The Brown Widow Spider, Mattie Harris

Honors College Theses

Widow spiders (genus Latrodectus) are well-known for their potent venom. Seven latrotoxin proteins constitute the main components of widow spider venom. The vertebrate specific (α-latrotoxin) and insect specific (α-latroinsectotoxin) latrotoxins have been well-characterized with respect to structure and function. Regulation of latrotoxin gene expression is not well understood but sex and feeding could be factors influencing production. In this study, I used quantitative qPCR to (1) characterize the expression patterns of both the insect and vertebrate specific latrotoxins in male and female brown widow spiders (Latrodectus geometricus) to characterize sex-biased expression and to (2) study expression patterns …


Effects Of 17Α-Ethinylestradiol (Ee2) On Gonadal Development And Gene Expression In Larval Mummichog (Fundulus Heteroclitus), Carly Sing-Judge Jan 2022

Effects Of 17Α-Ethinylestradiol (Ee2) On Gonadal Development And Gene Expression In Larval Mummichog (Fundulus Heteroclitus), Carly Sing-Judge

Theses and Dissertations (Comprehensive)

The mummichog (Fundulus heteroclitus) is a small-bodied estuarine fish that inhabits the North American east coast and is often used as a model adult saltwater fish in environmental bioassays. This study aimed to describe gonadal development and gene expression levels in five-week-old mummichog under control conditions and following 17α-ethinylestradiol (EE2) treatment in order to better understand the susceptibility of sex determination (SD) and gonadal differentiation (GD) processes following contaminant exposure. In the first experiment, eggs were fertilized, collected and incubated in the laboratory for three weeks, then yolk-sac larvae were grown out for five weeks and …


Interspecific Gene Flow Potentiates Adaptive Evolution In A Hybrid Zone Formed Between Pinus Strobiformis And Pinus Flexilis, Mitra Menon Jan 2020

Interspecific Gene Flow Potentiates Adaptive Evolution In A Hybrid Zone Formed Between Pinus Strobiformis And Pinus Flexilis, Mitra Menon

Theses and Dissertations

Species range margins are often characterised by high degrees of habitat fragmentation resulting in low genetic diversity and higher gene flow from populations at the core of the species range. Interspecific gene flow from a closely related species with abutting range margins can increase standing genetic diversity and generate novel allelic combinations thereby alleviating limits to adaptive evolution in range margin populations. Hybridization driven interspecific gene flow has played a key role in the demographic history of several conifer due to their life history characteristics such as weak crossability barriers and long generation times. Nevertheless, demonstrating whether introgression is adaptive …


Plasticity And The Impact Of Increasing Temperature On A Tropical Ectotherm, Adam A. Rosso Jan 2020

Plasticity And The Impact Of Increasing Temperature On A Tropical Ectotherm, Adam A. Rosso

Electronic Theses and Dissertations

Organisms may respond to climate change through behavior, genetic adaptation, and/or phenotypic plasticity. Tropical ectotherms are thought to be especially vulnerable to climate change because most have a narrow range of thermal tolerance while living close to their upper thermal tolerance limits. Additionally, many tropical species live in closed-canopy forests, which provide homogenous thermal landscapes that prevent behavioral compensation for stressfully warm temperatures. Finally, tropical ectotherms are thought to have decreased capacity for phenotypic plasticity because they have evolved in thermally stable environments. We tested gene expression patterns and phenotypic plasticity in the Panamanian slender anole by a) measuring changes …


Divergent Responses Of Larval And Juvenile Blue Mussels To Low Salinity Exposure, Melissa A. May May 2017

Divergent Responses Of Larval And Juvenile Blue Mussels To Low Salinity Exposure, Melissa A. May

Electronic Theses and Dissertations

In this study, we compared the osmotic stress response of larval and juvenile blue mussels (Mytilus edulis) at the transcriptomic, metabolomic, and whole organism levels. Blue mussels inhabit coastal areas, where they face climate-induced reductions in nearshore salinity. Despite their ecological and economic importance, scientists do not fully understand the underlying transcriptomic and cellular mechanisms of the osmotic stress response in blue mussels or how the ability to respond to stress changes throughout development. Blue mussels spend the first weeks of life developing through several larval stages in the plankton. These early life history stages are more vulnerable …


The Effects Of 4-Nonylphenol On The Immune Response Of The Pacific Oyster, Crassostrea Gigas, Following Bacterial Infection (Vibrio Campbellii), Courtney Hart Aug 2016

The Effects Of 4-Nonylphenol On The Immune Response Of The Pacific Oyster, Crassostrea Gigas, Following Bacterial Infection (Vibrio Campbellii), Courtney Hart

Master's Theses

Endocrine disrupting chemicals (EDCs) are compounds that can interfere with hormone signaling pathways and are now recognized as pervasive in estuarine and marine waters. One prevalent EDC in California’s coastal waters is the xenoestrogen 4-nonylphenol (4-NP), which has been shown to impair reproduction, development, growth, and in some cases immune function of marine invertebrates. To further investigate effects of 4-NP on marine invertebrate immune function we measured total hemocyte counts (THC), relative transcript abundance of immune-relevant genes, and lysozyme activity in Pacific oysters (Crassostrea gigas) following bacterial infection. To quantify these effects we exposed oysters to dissolved phase …