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Contemporary Morphological Evolution In A Lacustrine Population Of Threespine Stickleback, Rose Watts
Contemporary Morphological Evolution In A Lacustrine Population Of Threespine Stickleback, Rose Watts
Biology
In the face of rapidly changing environments, some populations go through contemporary evolution in response to altered selective pressures. In this situation, changes in morphology and behavior can be observed to monitor phenotypic transitions. In adaptive radiations such as the threespine stickleback, Gasterosteus aculeatus, species complex, both re-expression of ancestral phenotypes and the expression of novel phenotypes have been detected. I monitored a population of threespine stickleback in Lynne Lake, Alaska, which is undergoing rapid environmental changes due in part to an increase in primary productivity in the lake. Changes have been documented in the body size and foraging behavior …
The Population Genomics Of Human Microrna Gene Copy Number Variation, Julianne Murphy
The Population Genomics Of Human Microrna Gene Copy Number Variation, Julianne Murphy
Biology
Copy number variation (CNV) is a class of small structural variation defined as loci that vary in their number of copies between individuals due to duplication or deletion. CNV is pervasive in the human genome and can influence phenotype. However, little is known about CNV of genes encoding regulatory microRNAs (miRNAs). We developed a computational method based on variation in read depth to estimate miRNA copy number. This approach was used to quantify the copy number of 1,805 miRNA loci across 161 Yoruban (YRI) and European (CEU) genomes. The vast majority of autosomal miRNA encoding genes were present at a …
Population Genetics Of Freshwater Pearl Mussel (Margaritifera Margaritifera) In Central Massachusetts And Implications For Conservation, Stefanie Farrington
Population Genetics Of Freshwater Pearl Mussel (Margaritifera Margaritifera) In Central Massachusetts And Implications For Conservation, Stefanie Farrington
Biology
The freshwater pearl mussel Margaritifera margaritifera is an ecologically-important globally-endangered species, yet little is known about biodiversity and population genetics in North American populations. We focused our study on M. margaritifera from central and eastern Massachusetts, USA, to better understand the historical impact of damming and habitat fragmentation on local population structure and genetic diversity. In order to examine the local population genetics of M. margaritifera, we generated ~300 informative single nucleotide polymorphisms (SNPs) from 59 individuals across 6 geographic locations, using the RAD-seq approach. We also gleaned genotypes from publicly available RNA-seq data of 23 French M. margaritifera samples. …
Connections Between Protein Misfolding And Monobenzone-Induced Vitiligo, Senegal Carty
Connections Between Protein Misfolding And Monobenzone-Induced Vitiligo, Senegal Carty
Biology
Vitiligo, an autoimmune disease affecting melanocytes, causes areas of skin to completely lose pigment. These colorless lesions can spread, eventually leading to the complete absence of skin and hair pigment in some patients. Exposure to monobenzyl ether of hydroquinone (MBEH), or monobenzone, is an environmental trigger of this disfiguring disease. In this study, we aimed to elucidate the mechanism of this phenomenon by studying monobenzone's inhibition of tyrosinase, a melanocyte enzyme that plays a key role in melanin production. As tyrosinase is an oxidizing enzyme, we hypothesized that when inhibited by monobenzone, resulting elevated levels of reactive oxygen species (ROS) …
Quantification Of Phenotypic Variation In Populations Of Newfoundland Threespine Stickleback (Gasterosteus Aculeatus), Nathan R. Biedak
Quantification Of Phenotypic Variation In Populations Of Newfoundland Threespine Stickleback (Gasterosteus Aculeatus), Nathan R. Biedak
Biology
Phenotypic variation in morphology driven by ecological factors has been well characterized in Alaskan and British Columbian populations of threespine stickleback, with studies demonstrating that the variation is extensive in a wide variety of anti-predator traits and body shape. In contrast, the limited published studies of stickleback in eastern North America suggest that there is relatively little among-population phenotypic variation in anti-predatory armor and body shape. Recent samples obtained from 30 populations of stickleback in Newfoundland, from a wide array of habitats, indicate that the earlier suggestion of relatively limited phenotypic diversity may need to be reevaluated. Using geomorphic morphometrics …
Temporal Patterns Of Armor And Body Shape Evolution Of The Threespine Stickleback In Scout Lake, Alaska, James Patrick Keogh
Temporal Patterns Of Armor And Body Shape Evolution Of The Threespine Stickleback In Scout Lake, Alaska, James Patrick Keogh
Biology
Invasive predators can have devastating ecological and evolutionary impacts on native prey species within the ecosystems they invade. These effects may be particularly pronounced when the predator is novel to the prey, a situation that is on-going in southcentral Alaska, where the large and voracious northern pike are invading the native range of the threespine stickleback. In this area, pike have caused the extirpation of several populations of stickleback, yet in some instances stickleback have persisted. Here, we report on phenotypic changes following introduction of pike into Scout Lake, Alaska, in which the stickleback persisted.
Population Genomics Reveals Loss Of Odorant Receptor Gene Repertoire During Polar Bear (Ursus Maritimus) Evolution, Natalya Katerina Specian
Population Genomics Reveals Loss Of Odorant Receptor Gene Repertoire During Polar Bear (Ursus Maritimus) Evolution, Natalya Katerina Specian
Biology
The polar bear (Ursus maritimus) and brown bear ( Ursus arctos) are a recently diverged species pair but are morphologically, behaviorally, and physiologically distinct. These phenotypic differences reflect adaptation to local environments. Previous research aimed to identify the genetic underpinnings of adaptive traits focused mainly on single nucleotide polymorphisms (SNPs), while ignoring copy number variation (CNV). CNV refers to loci that vary in their number of copies between individuals due to duplication or deletion. Here, we computationally predicted whole genome copy number profiles across 17 polar bear and 9 brown bear genomes using FREEC. We identified hundreds of genes overlapping …
Proteolytic Degradation Of Ctf57 And Abeta Polypeptides By Insulin-Degrading Enzyme: Biophysical Studies With Implications For Alzheimer's Disease, Claire A. Krasinski
Proteolytic Degradation Of Ctf57 And Abeta Polypeptides By Insulin-Degrading Enzyme: Biophysical Studies With Implications For Alzheimer's Disease, Claire A. Krasinski
Biology
Alzheimer's Disease (AD) is today's most common type of dementia, affecting approximately 5.4 million Americans. After many years of basic science research and clinical trials, there is still no cure for the disease. We hypothesize that the impaired degradation/clearance of CTF57 and Abeta polypeptides from the brain contributes to the onset of AD. This work expands upon the honor's thesis with emphasis on the proteolytic degradation of these species by insulin-degrading enzyme (IDE). Chapter 3 investigates CTF57's global conformation in solution and its proteolysis using various biophysical techniques. CTF57 forms a reproducible beta-sheet that is non-fibrillar, anti-parallel, and degradable near …
A Functional Analysis Of Drosophila Plcgamma And The Screening For A Novel Inhibitor, Michelle K. Latino
A Functional Analysis Of Drosophila Plcgamma And The Screening For A Novel Inhibitor, Michelle K. Latino
Biology
The epidermal growth factor receptor, EGFR, pathway is a highly conserved and complicated pathway required for cell growth, proliferation, migration, and proper regulation of the pathway is required for normal development (reviewed by Fischer et al., 2003). Due to the pathways role in development, the EGFR pathway is often implicated with various diseases including cancer. The EGFR pathway is regulated by various proteins including by PLCgamma which works to regulate the pathway by promoting motility, adhesion, and differentiation (Murillo-Maldonado et al., 2011; Butchar et al., 2012; Shepard et al., 2006). Because of the role PLCgamma plays in cell proliferation, it …
Functionalization Of Linear Poly(Ethylenimine) As Dna-Binding Polymer For Gene Therapy Application, Thanaphorn Suk-In
Functionalization Of Linear Poly(Ethylenimine) As Dna-Binding Polymer For Gene Therapy Application, Thanaphorn Suk-In
Biology
Gene therapy is a technique used to combat diseases by correcting the defective gene responsible for the disease to alleviate its symptoms and restore normal function to the defective gene. Gene therapy uses vectors to deliver a functional copy of the defective gene targeted towards the defective cell to replace the defective gene with the functional one via gene transfer (1). Over the years, gene delivery vectors available for gene therapy have gradually evolved, leading to the development of new and better vectors for gene delivery. These advances contribute largely to the growing successes of gene therapy and its application …
Investigating Differential Methylation In Apis Mellifera Worker Bee Sub-Castes, Ethan Wainblat
Investigating Differential Methylation In Apis Mellifera Worker Bee Sub-Castes, Ethan Wainblat
Biology
DNA can undergo epigenetic modification at cytosine nucleotides by the addition of a methyl group (CH3). These alterations, which are frequently located within the exons in social insects, may regulate transcription and/or splicing of genes. I analyzed the methylome at two developmental stages of the worker caste in the honey bee (Apis mellifera), specifically the nurse stage and the forager stage. The methylation appeared to be mostly in exons relative to the introns and exons. I then examined genome wide methylation between the two sub-castes and noticed twenty-one (21) differentially methylated genes and seventy-one (71) differentially methylated regions. The forager …
Evolution Of Nervous System Centralization: Role Of Bmp Signaling In Neural Fate And Dorsal-Ventral Axis Specification In Capitella Teleta, Christie Joyce
Evolution Of Nervous System Centralization: Role Of Bmp Signaling In Neural Fate And Dorsal-Ventral Axis Specification In Capitella Teleta, Christie Joyce
Biology
Bone Morphogenetic Protein (BMP) signaling plays an important role in establishing the dorsal-ventral (D-V) axis across Bilateria. BMP signaling has also been implicated in neural fate specification in several bilaterians that possess centralized nervous systems. The classic examples are found in vertebrates and Drosophila melanogaster, where opposing gradients of BMP2/4/Dpp and Chordin/Sog specify the D-V axis and the nervous system arises on the Chordin/Sog side of the early embryo due to the anti-neural role of BMPs. These similarities have been used as support for the hypothesis that the bilaterian ancestor possessed a centralized nervous system and that BMP signaling delimited …
The Effect Of Substrate Unevenness And Irregularity On Locomotor Performance And Kinematics Of Curly-Tailed Lizards, Marian E. Crockett
The Effect Of Substrate Unevenness And Irregularity On Locomotor Performance And Kinematics Of Curly-Tailed Lizards, Marian E. Crockett
Biology
Uneven surfaces are ubiquitous in nature and animals must frequently move across them, yet their effects on locomotion are not well understood. I studied how surface unevenness and irregularity of substrates made of large particles affect the locomotor performance and kinematics of the terrestrial generalist sprinter, the Northern Curly-Tailed Lizard (Leiocephalus carinatus). I compared a flat surface (even), three sizes of spheres (regular but uneven surfaces), and three sizes of natural rocks (irregular and uneven surfaces). As the size of the particles increased, the unevenness of the surface increased. The lizards ran at similar speeds on all substrates, but compensated …