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Targeted Gene Replacement To Mimic Familial Hypertrophic Cardiomyopathy In Caenorhabditis Elegans, Craig Alan Almeida

Doctoral Dissertations

The identification in invertebrates of genes homologous to human disease genes provides the possibility to broaden the spectrum of model organisms to include experimental invertebrates. The goal of this study is to test the possibility of using Caenorhabditis elegans as an animal model for the inherited human heart disorder familial hypertrophic cardiomyopathy. In 10-30% of the affected families that have been studied, this disease is caused by mutations in the $\beta$-cardiac myosin heavy chain (MHC) gene. The most common of these mutations results in the replacement of an evolutionarily conserved arginine residue (R403) with glutamine (R403Q). While this information has …

Relationship Of Critical Photoperiod Of Short-Day Parents To Frequency Of Day-Neutral Progeny In Short-Day X Day-Neutral Crosses Of Fragaria X Ananassa, Christina Marie Cundari

Doctoral Dissertations

Critical photoperiod for flowering was determined for short-day (SD) and day-neutral (DN) genotypes of strawberry used in SD x DN crosses to investigate whether variation in critical photoperiod contributes to variation in frequency of DN progeny and, hence, may be an effective selection criterion for screening SD genotypes for use as parents in breeding regionally-adapted DN cultivars. Twelve SD and four DN genotypes were grown in controlled environments under eight photothermal regimes (four photoperiods (9, 11, 13, 15 hr) x two day/night temperatures (19/14 and 24/19$\sp\circ$C)). Among the SD genotypes, critical photoperiod varied more under cool than warm regimes. Under …

The Purification And Characterization Of An Extrapallial Fluid Protein From The Mollusc, Mytilus Edulis, Stephen Joseph Hattan

Doctoral Dissertations

Shell deposition within the bivalve mollusc Mytilus edulis is regulated by the macromolecules of the extrapallial fluid (EP fluid). These mineralization regulating macromolecules are thought to be responsible for the nucleation, growth regulation and growth cessation of the CaCO$\sb3$ mineral crystals that will inevitable constitute $\geq$95% of the mature shell.

This dissertation presents the results of the purification and characterization of the major EP fluid protein of the bivalve Mytilus edulis. The major EP fluid protein was determined to comprise 56% of the total fluid protein and to consist of 7.25% by weight carbohydrate. The protein was purified though a …

Formation And Fate Of Methyltin Compounds In The Great Bay Estuary (New Hampshire), Anne M. Falke

Doctoral Dissertations

Methyltin compounds (MeSn), which are not of anthropogenic origin, are common in estuaries, particularly in the marsh grass Spartina alterniflora. During the 1989 growing season, S. alterniflora leaves collected from three locations in the Great Bay Estuary were analyzed for MeSn and inorganic tin by hydride generation/atomic absorption spectrophotometry (HG-AAS). Total MeSn concentrations showed a sharp increase early in the season, reaching a maximum on May 23, then gradually decreased. Statistical calculations verified that date was a significant contributor to the observed variance, while location was not.

Two years later the seasonal study was expanded to include below ground portions …

Life History And Reproductive Biology Of The Estuarine Nudibranch Tenellia Adspersa (Nordmann, 1845), Charles Morgan Chester

Doctoral Dissertations

Tenellia adspersa is a small (5-7 mm) estuarine nudibranch. Tenellia lives in a highly variable environment and feeds on many gymnoblastic and calyptoblastic hydroids. I undertook a field study at four sites in the Great Bay Estuary (Durham, New Hampshire) to assess the amount of variability in abiotic and biotic factors. Environmental parameters (temperature and salinity) and the availability of hydroid prey (Cordyolophora lacustris and Obelia spp.) varied within the generation time of Tenellia and could affect its life history.

Laboratory studies compared the growth rate of the hydroid, Cordylophora to the growth rate and predation rate of Tenellia. The …

The Effects Of Primary Olfactory Cortical And Thalamic Lesions On Olfactory Continuous Non-Matching To Sample And Discrimination In The Rat, Yueping Zhang

Doctoral Dissertations

Forty-two male rats were pretrained on the olfactory continuous delayed non-matching to sample (CDNMTS) task. They were then matched for performance and randomly assigned to one of the following six treatment groups: excitotoxic lesions of pyriform cortex, later entorhinal cortex, lateral internal medullary lamina (L-IML), mediodorsal nucleus (MDn), nonspecific nuclei, and sham control. After recovery from surgery, the rats were retrained on the olfactory CDNMTS. Delay effects were examined by manipulating retention intervals (RI), with five RIs (4, 6, 9, 13.5, and 20.25 s) randomly mixed within each session. The number of odor stimuli used in each session varied from …

Ecophysiology Of Metal-Reducing Aeromonas And Shewanella Strains From Great Bay Estuary, Victoria Knight

Doctoral Dissertations

The seasonal abundance and distribution of mesophilic aeromonads at seven sites in Great Bay Estuary, NH were monitored over a 24 month period. Total heterotrophic bacteria, total and fecal coliforms, salinity, temperature, pH, total suspended solids, and chlorophyll were also measured in the samples. Aeromonads were isolated at each site throughout the year with the highest incidence and population density in the late summer to early fall. Aeromonad abundance correlated positively with the incidence of coliforms, temperature, and salinity.

Aeromonas hydrophila ATCC 7966 grew anaerobically by using NO$\sb3\sp-$, fumarate, Fe (III), Co (III), or Se (VI) as terminal electron acceptors. …

Variation In Transposable Element Sequence And Activity In The Nematode Caenorhabditis Elegans, Jeremy David Glasner

Doctoral Dissertations

Eukaryotic genomes are replete with transposable elements. The nematode C. elegans will be the first multicellular organism to have its genome completely sequenced. This sequence will allow identification of all the transposon and transposon-related sequences from a single genome. In anticipation of the complete genome sequence I have initiated a series of analyses of sequences from the C. elegans genome database that share significant similarity to known families of transposons. Several members of known transposon families were observed along with a plethora of sequences related to these known transposons. Cladistic analyses were used to describe the relationships among transposons and …

Patterns Of Base Composition Within And Between Animal Mitochondrial Genomes, Nicole T. Perna

Doctoral Dissertations

Nucleotide composition of a DNA molecule is a product of base substitution. Variation in nucleotide composition indicates a change in the pattern of substitution at either the level of the underlying mutational spectrum or the constraints imposed by natural selection. This work explores patterns of nucleotide usage within and between animal mitochondrial genomes and the evolutionary mechanisms that have shaped these patterns. Fourfold degenerate sites are expected to reflect the underlying mutational spectrum. Three simple measures of compositional bias, taking into account the strand-specific nature of nucleotide distribution in mtDNA, reveal considerable variation among fourfold degenerate sites of metazoan mitochondrial …

Ecological Patterns During Ontogeny In The Bicolor Damselfish, Stegastes Partitus, Poey, Richard Stephen Nemeth

Doctoral Dissertations

This dissertation examined the ecological constraints during the early life history of the bicolor damselfish, Stegastes partitus Poey (Perciformes, Pomacentridae). A series of studies, conducted in Teague Bay, St. Croix and Discovery Bay, Jamaica between 1991 and 1996, determined the cause of variation in length of the planktonic larval period, the effect of larval history on settlement success and examined the causes behind the patterns of distribution and population structure seen throughout its geographic range. Variable growth rates in early-stage larvae established a canalized trajectory toward larval competence and provides a mechanism for determining planktonic duration. Using otolith microstructure I …

Competition And Dispersal In The Regulation Of Plant Species Richness On Carex Stricta Tussocks, Leonard Alexander Lord

Doctoral Dissertations

Many wetland plant species can be found growing on Carex stricta Lam. (tussock sedge) tussocks in freshwater marshes. Based on Grime's model of plant species richness, the objectives of this research were to: (1) examine if dispersal characteristics vary among C. stricta marshes in a manner that could potentially influence species richness on individual tussocks, and (2) examine how variation in propagule availability may interact with standing crop and leaf litter to regulate species richness on individual tussocks. All of the research was conducted in southeastern New Hampshire.

Dispersal characteristics were quantified in five wetlands representing a broad range of …

Molecular Identification, Coastal Distribution And Recruitment Of Cucmaria Frondosa Larvae In The Western Gulf Of Maine, Dorothy E. Medeiros-Bergen

Doctoral Dissertations

Understanding of the physical transport of larvae requires information on adult source populations, larval distributions, larval behavior and physical oceanography. Identification of three species (Cucumaria frondosa, Psolus fabricii and Chiridota laevis) of holothurian larvae in the western Gulf of Maine was done with a simple detection protocol, using oligonucleotide probes, for the 16S rRNA portion of the mitochondrial DNA genome. More than 2000 larvae and new recruits were analyzed. This technique revealed that of the three species present in the plankton, Cucumaria larvae dominated the samples comprising $>$90% of the larvae and 95% of new recruits during 1993. Cucumaria …