The activity of plant 9-lipoxygenases (LOXs) influences the outcome of Arabidopsis thaliana interaction with pathogen and insects. Evidence provided here indicates that in Arabidopsis, 9-LOXs facilitate infestation by Myzus persicae, commonly known as the green peach aphid (GPA), a sap-sucking insect, and infection by the fungal pathogen Fusarium graminearum. in comparison to the wild-type plant, lox5 mutants, which are deficient in a 9-lipoxygenase, GPA population was smaller and the insect spent less time feeding from sieve elements and xylem, thus resulting in reduced water content and fecundity of GPA. LOX5 expression is induced rapidly in roots of GPA-infested plants. This increase in LOX5 expression is paralleled by an increase in LOX5-synthesized oxylipins in the root and petiole exudates of GPA-infested plants. Micrografting experiments demonstrated that GPA population size was smaller on plants in which the roots were of the lox5 mutant genotype. Exogenous treatment of lox5 mutant roots with 9-hydroxyoctadecanoic acid restored water content and population size of GPA on lox5 mutants. Together, these results suggest that LOX5 genotype in roots is critical for facilitating insect infestation of Arabidopsis. in Arabidopsis, 9-LOX function is also required for facilitating infection by F. graminearum, which is a leading cause of Fusarium head …

The purpose of this project is to produce a complete and thorough notebook that may be used to supplement laboratory coursework. Its intent is to be used primarily by the students to aid them in understanding background information and the proper laboratory procedures involved in various types of experiments. The laboratory notebook is a summation of all the experiments and procedures used in the six-credit hour Advanced Microbial and Molecular Biology (BIOL 5160) course offered during the summer semester at the University of North Texas. This class is a team taught effort by Professors O'Donovan and Kunz. The course is constructed as an intensive practice exercise to teach the student about gene mutations, biosynthetic pathways, preparation and analysis of plasmid DNA, and many other topics included in the notebook.

A comparative study was made of environmental variables and the density, biomass, diversity, and species composition of macroinvertebrates in areas downstream from a dam with a hypolimnetic release (Hungry Horse Dam on the Flathead River) and a dam with a selective withdrawal system (Libby Dam on the Kootenai River). A major objective of this study was to examine the response of macroinvertebrate communities to defined environmental gradients in temperature, flow, substrate, and food-related variables (periphyton, particulate organic carbon in the seston). In addition, the effects of experimental manipulations in discharge on macroinvertebrate drift and stranding were assessed, and the effects of temperature on the growth rates and emergence of five species of insects were measured.

Twenty-two natural populations of the red shiner minnow, Notropis lutrensis were examined for morphological and genetic variation. This research was aimed at testing the hypothesis that morphological and genetic variation was primarily influenced by the degree of gene flow between populations. Ten linear measurements were taken from each of 1320 specimens. Morphological characters were adjusted for differential growth by least squares linear regression techniques. Genetic variability was estimated for each individual red shiner through the methods of starch gel electrophoresis. Twenty presumtive gene loci were resolved.

Drumming behavior is described for the first time in 16 North American species of Plecoptera, and signals of a 17th species, Isogenoides zionensis, are further detailed. The effective distance over which drumming signals may be transmitted was tested for four communication modes. Results indicate that substratum vibrations are far superior to sound in the transmission of drumming signals, and that dense substrates such as rocks are poor channels for signal transfer. Long communication periods between stonefly pairs of Taeniopteryx burksi resulted in some alterations from initial signaling characteristics.

Four species of net-spinning caddisflies, Hydropsyche simulans Ross, Cheumatopsyche lasia Ross, Cheumatopsyche campyla Ross and Chimarra obscura (Walker) are common in the regulated portions of the Brazos River. Hydropsyche simulans spun capture nets with the largest meshdimensions; the two Cheumatopsyche species' nets had the next largest meshes, and Chimarra obscura spun nets with the smallest dimensions. Cheumatopsyche lasia and C. campyla constructed nets with similar sized meshes. The number of individuals m~2 and standing crop biomass were not significantly different among low, medium, and high velocities. Early hydropsychid instars fed on detritus while later instar H. simulans and C. campyla had larger proportions of animal material. Guts of later instar C. lasia individuals had a greater percentage of algae and diatoms.

This presentation contains an analysis of ~600 solicitation emails related to 317 scholarly journals received within a one-year period to assess the quality of publishing venues available.