Rett Syndrome (RTT, OMIM 312750) is a pervasive autism spectrum disorder affecting 1 in 10,000 females. The majority of cases are caused by mutations in the X-linked gene MECP2. The RTT phenotype appears to be caused by impaired synapse maturation or maintenance, resulting in disrupted autonomic nervous system function, mental retardation, ataxia, apraxia, and movement stereotypies. While not a neurodegenerative disorder RTT is marked by region-specific reductions in brain volume. We examined the morphology of YFP-expressing Layer 5 pyramidal neurons in the motor cortex of a MeCP2 mutant RTT mouse model. Mutant mice exhibited smaller somata and reduced dendritic lengths in both the apical tuft and basal arbor. Basal dendritic branching was also reduced proximal to the soma. These changes are consistent with the motor deficits observed in mutant mice and in human RTT patients. Altered expression of a Thy-1-YFP reporter transgene in MeCP2 mutant mice is also described.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2005. / (UnM)AAI3202116. Adviser: Arthur L. DeVries. Source: Dissertation Abstracts International, Volume: 67-02, Section: B, page: 0633.

Although food quality is thought to play an important role in the survival of marine copepods, the extent of natural variability in food quality remains poorly characterized. Here I characterize the different scales at which food quality varies in copepods of the Strait of Georgia, British Columbia, Canada. Significant interannual variability occurs in the diet of Neocalanus plumchrus in the Strait of Georgia. Between 2001-06 the fatty acid profiles of N. plumchrus switched from omnivorous, oceanic signatures to herbivorous, diatom-dominated signatures. An index of food quality (DHA/EPA) is strongly correlated to the abundance of diapausing N. plumchrus, suggesting that the relative proportion of essential fatty acids provided by dinoflagellates and diatoms are related to the survival of this species. Combined fatty acid and stable isotope analysis indicated that the spring calanoid copepods of the Strait of Georgia occupy three trophic positions: Eucalanus bungii is herbivorous, Calanus marshallae and N. plumchrus are omnivorous, while Euchaeta elongata is carnivorous. Oceanic conspecifics of Strait of Georgia copepods experience a more omnivorous diet, as indicated by the presence of higher proportions of flagellate and carnivory markers, and lower proportions of diatom-based markers in their fatty acids. Despite spatial differences in the quality of their diets, the relative trophic positions of these copepods are constant as indicated by their stable isotope signatures. There is a correlation between the trophic information provided by stable isotopes and fatty acids. However, stable isotopes are not sensitive enough to capture the range of dietary variability observed in fatty acids, and fatty acids do not always provide reliable markers of carnivory and trophic position. Over the span of a season, copepods can utilize a wide range of dietary items including diatoms, flagellates, bacteria, detritus and microzooplankton. Copepods can switch from herbivory to carnivory in response to declining chlorophyll concentrations after the spring bloom, and are occasionally able to utilize detrital and bacterial sources. I conclude that the quality of copepod diets in the SoG varies on interannual, interspecific and seasonal scales. The implications of these findings are discussed in relation to ecosystem models of the area, and to copepod physiology.

Doctor of Philosophy / Department of Biology / Donald W. Kaufman / Glennis A. Kaufman / Little is known about nightly activity patterns of nocturnal small mammals under natural conditions, and how these activity patterns might be affected by photoperiod, season, and sex, age, and reproductive status of individuals. The main objectives of this research were: 1) to find an appropriate method for marking individual deer mice (Peromyscus maniculatus) so that their activity could be monitored remotely; 2) to design a portable activity-monitoring system to investigate temporal patterns of shelter use by deer mice under natural conditions; 3) to determine the influence of environmental conditions such as photoperiod and season on nightly activity of deer mice; and 4) to compare effects of demographic or physiological factors such as sex, age, and reproductive status on nightly activity of deer mice at artificial burrows in tallgrass prairie. In general, commencement of activity was correlated positively with timing of sunset, and time of retirement to the burrow was correlated positively with sunrise. Among adults, males first emerged from the burrow earlier and made more trips of shorter duration in a night than did females, although total duration of trips was similar. Return visits and subsequent stays typically were shorter for males than females, but total time spent in the burrow and retirement time relative to sunrise were similar for both sexes. Young deer mice emerged significantly later, made more trips of shorter duration, spent less total time outside, and retired to their burrow earlier than adults. Reproductive females emerged later, made fewer trips of generally longer duration, and spent shorter total amounts of time away from the burrow each night than non-reproductive females. Return visits of reproductive females were of longer duration than non-reproductives, but total time spent inside and time of retirement for the night did not differ relative to reproductive status. From parturition through lactation, activity of females showed a number of directional trends. Results suggest that under natural conditions, activity patterns of deer mice are highly variable but responsive to both the changing physical environment and internal conditions related to sex-specific maximization of fitness.

Peregrine falcon subspecies taxonomy is widely debated due to uncertainty in their evolutionary history and unresolved phylogenetic reconstruction using both morphological and molecular data. Previous genetic work has shown limited support for subspecies taxonomy largely as a result of molecular markers used, potential contemporary gene flow, incomplete lineage sorting, and ancestral polymorphisms. With the advent of next-generation sequencing, the cost of generating large amounts of sequence data has dropped significantly, making whole genome re-sequencing (WGR) studies of non-model organisms more tangible. In this study, WGR methods have been utilized to investigate the phylogenetic relationships among all 20 currently recognized peregrine falcon subspecies. By generating whole-genome data for all 20 subspecies, subspecies specific diagnostic SNPs have been identified to aid in subspecies delimitation. Results of this study broadly support current subspecies, however, reveal that further study is needed to investigate regional relationships among subspecies in Asia, Australia, and western North America. With these results, conservation efforts can be further supported by allowing for accurate delimitation of local subspecies and subspecies boundaries.

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