Thesis (M.S.)--State University of New York at Binghamton, Biology Department, 2006. / Includes bibliographical references.

<p>Mushrooms are believed to have a great potential for production of bioactive metabolites e. g. terpenes, a group of interesting compounds with diverse chemical properties such as antitumour and antibacterial activity. Cop6 is a terpene cyclase isolated from the mushroom <em>Coprinus cinereus</em> that catalyzes the cyclization of farnesyl diphosphate (FPP) to mainly α-cuprenene. In this study gas chromatography combined with mass spectroscopy (GC-MS) is used to analyze the product profile of Cop6 mutants created by PCR based site directed mutagenesis. The goal is to produce trichodiene, the parent hydrocarbon in the biosynthesis of trichothecene antibiotics and mycotoxins. Valine instead of tyrosine in amino acid position 195 resulted in cyclisation of (E)-β-Farnesene and (3Z,6E)-α-Farnesene besides the products of the wild type enzyme. Another mutant with aspartic acid instead of asparagine in position 224 resulted in the synthesis of β-Bisabolene except for α-cuprenene and methionine in position 74 instead of isoleucine killed the activity of the cyclase. Furthermore, an attempt to saturation of position 98 was made, resulting in four mutants. Two of them essentially killed the activity of the cyclase whereas two had minor effect of the product profile compared to the wild type. </p>

Mushrooms are believed to have a great potential for production of bioactive metabolites e. g. terpenes, a group of interesting compounds with diverse chemical properties such as antitumour and antibacterial activity. Cop6 is a terpene cyclase isolated from the mushroom Coprinus cinereus that catalyzes the cyclization of farnesyl diphosphate (FPP) to mainly α-cuprenene. In this study gas chromatography combined with mass spectroscopy (GC-MS) is used to analyze the product profile of Cop6 mutants created by PCR based site directed mutagenesis. The goal is to produce trichodiene, the parent hydrocarbon in the biosynthesis of trichothecene antibiotics and mycotoxins. Valine instead of tyrosine in amino acid position 195 resulted in cyclisation of (E)-β-Farnesene and (3Z,6E)-α-Farnesene besides the products of the wild type enzyme. Another mutant with aspartic acid instead of asparagine in position 224 resulted in the synthesis of β-Bisabolene except for α-cuprenene and methionine in position 74 instead of isoleucine killed the activity of the cyclase. Furthermore, an attempt to saturation of position 98 was made, resulting in four mutants. Two of them essentially killed the activity of the cyclase whereas two had minor effect of the product profile compared to the wild type.

Terrestrial salamanders of the genus Plethodon are among many vertebrates possessing both main olfactory and vomeronasal systems, which the Volatility Theory posits are for detection of volatile and soluble olfactory cues, respectively. Further recent work showing a high amount of convergence between the two olfactory subsystems at the level of the central nervous system suggests complementary or overlapping roles for them. This study examined the use of the olfactory subsystems in prey detection from the perspectives of behaviour and neurobiology. Red-backed salamanders, Plethodon cinereus, were observed in standardized behavioural assays with both volatile and soluble prey olfactory cues. Naïve salamanders showed an increase in nosetapping as well as a side preference in the presence of soluble and volatile prey cues when tested in a 22°C day/20°C night room. In a 15°C day /12°C night room, salamanders increased nosetapping in the presence of soluble prey cues. Salamanders showed a pattern of responses that differed based on their previous experience with the assay, as well as the temperature of the testing room. Attempts to study the neurobiology of olfactory function in Plethodon shermani were inconclusive up to this point, but future directions are discussed. This study shows the importance of olfaction in prey detection by salamanders and that prey searching behaviour is exhibited in the exclusive presence of olfactory cues.

Habitat destruction and degradation are the most important threatening processes for the majority of species of conservation concern. As landscapes become more fragmented their spatial structure becomes increasingly important for the viability of wildlife populations. Therefore, understanding the dynamics of how populations interact with landscape structure is crucial for developing effective wildlife management and monitoring strategies. To achieve robust management, such an understanding should be incorporated into decision theory approaches for the design of management and monitoring strategies. Monitoring is a crucial component for assessing the outcome of management, because this can then be used to inform future management actions in an adaptive management framework. However, for many species, their spatial population dynamics are not well understood and objective management frameworks not well developed. In this thesis I use modelling approaches to develop the components of an adaptive management framework for species of conservation concern that occur in fragmented landscapes. I use the koala (Phascolarctos cinereus) as a study organism and specifically address three key components that are important for adaptive management. These components are: (1) the development of novel approaches for modelling and understanding spatial population processes, (2) the application of modelling approaches to develop general principles and methods for managing wildlife populations in fragmented landscapes and (3) the application of modelling approaches to identify the best spatio-temporal sampling strategies for monitoring population trends in fragmented landscapes. This research advances our understanding of the dynamics of wildlife populations in fragmented landscapes, but importantly also develops tools and general principles for the adaptive management of these populations. To improve our understanding of the dynamics of populations in fragmented landscapes I develop several novel modelling approaches. Firstly, I develop an approach for disassociating the effect of natural habitat and anthropogenic influences on population distributions using static occupancy models. This approach allows inferences to be made about how important the distribution of habitat is compared to other human-related factors. Secondly, I develop modelling approaches for understanding habitat selection and dispersal processes. In particular, I address common problems for modelling complex habitat selection processes and parameterising dispersal simulation models. The habitat selection models are novel because they account for habitat preferences that depend upon the spatial location of habitat. The novel emphasis for the dispersal models, is showing that pattern-oriented approaches are useful for parameterising dispersal simulation models, even when we have little data. These models make an important contribution to our understanding of and methods for understanding spatial population processes. These and other modelling approaches are then applied to some key management questions, in order to develop general principles and methods for wildlife management decision-making. These studies relate to identifying the best spatial allocation of different management strategies, the planning of road networks to minimise impacts on wildlife and the impact of different mortality rates on the ranking of habitat protection strategies. First, I show that the relative spatial distribution of habitat and anthropogenic influences has important implications for the spatial allocation of management strategies. Second, I show that increasing traffic volume on existing roads is generally preferential to building new roads in terms of minimising the impact on wildlife mortality. Third, I use a multi-criteria decision analysis to show that the spatial arrangement of protected habitat is much less important for populations subject to high mortality rates than those subject to low mortality rates. Finally, spatially-explicit modelling approaches are applied to questions related to how sampling effort should best be allocated spatially and spatio-temporally to monitor population trends. These studies reveal that the best sampling strategy depends predictably upon the monitoring objectives and the dynamics of the species. Using the principles developed, improved monitoring strategies and ultimately improved management strategies will be possible. This thesis makes an important contribution to the development of adaptive management strategies for wildlife populations in fragmented landscapes. To implement an adaptive management approach, the modelling, management and monitoring components must be explicitly linked. By developing each of these components, this thesis provides a strong basis from which an adaptive management framework can be constructed. How this may be achieved and key areas for future research are discussed.

No description available.

The potential of basin wildrye (Elymus cinereus Scribn. & Merr. 'Magnar') and tall wheatgrass [Agropyron elongatum (Host) Beav. 'Jose '] to establish on saline, arid rangelands in the Great Basin in relation to soil water and salinity was compared in field and laboratory experiments. Tall wheatgrass had higher emergence and establishment on a nonsaline and a saline soil (electrical conductivity of the saturation extract of 7 dS·m-1) over a range of spring precipitation as simulated by sprinkler irrigation. Basin wildrye will require supplemental irrigation to establish on soils of similar salinity. In the absence of precipitation, soil salinity increases and matric and osmotic potentials rapidly decrease as the surface soil dries in late spring. Germination and growth responses in relation to salinity and drought in laboratory experiments were consistent with emergence and establishment results in the field experiments. Tall wheatgrass had higher total germination, rate of germination and radicle growth under decreasing osmotic potentials and higher emergence under decreasing matric potentials than basin wildrye. Tall wheatgrass had greater root and shoot yield than basin wildrye when osmotic potentials in sand cultures were decreased by solutions of NaCl, Na2SO4 and CaCl2.Tall wheatgrass is more tolerant of salt and boron than basin wildrye, but basin wildrye is highly salt tolerant compared to most forage species. Tall wheatgrass had more rapid root elongation and more extensive root growth than basin wildrye seedlings grown in 60-cm soil columns filled with nonsaline and saline soil. Germination and growth of both species was reduced by ions in addition to the effects of water stress due to low osmotic potentials. Rate of germination and radicle growth of both species was less in salts than in isosmotic polyethylene glycol solutions. Seedlings exhibited less growth in saline than nonsaline soil even when plant water stress was minimal or when leaf water potentials were low but turgor was maintained by osmotic adjustment. Germination at low osmotic and matric potentials and root elongation in relation to salinity may be important plant responses to use in evaluating the potential for establishment of new plant materials on saline, arid rangelands.

No description available.

No description available.

No description available.