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Lincoln, NE, United States

Zagvazdina N.Y.,U.S. Department of Agriculture | Paris T.M.,University of Florida | Udell B.J.,U.S. Department of Agriculture | Stanislauskas M.,U.S. Department of Agriculture | And 3 more authors.
Annals of the Entomological Society of America

Insects and other animals sometimes modify behavior in response to changes in atmospheric pressure, an environmental cue that can provide warning of potentially injurious windy and rainy weather. To determine if Diaphorina citri (Hemiptera: Liviidae) calling, mate-seeking, and phototaxis behaviors were affected by atmospheric pressure, we conducted analyses to correlate responsiveness with pressure trends over periods up to 48 h before laboratory bioassays. Mean responsiveness increased or decreased depending on the magnitudes and directions of pressure changes measured over different periods up to 24 h before bioassays, and changed differently in calling and mate-seeking bioassays than in phototaxis bioassays. For example, mean responsiveness decreased in mating behavior bioassays but increased in phototaxis bioassays when atmospheric pressure changed more than one standard deviation over a 24-h period. Such a result is consistent with a hypothesis that there may be survival benefits to focusing energy on dispersal or migration rather than mating after occurrences of sustained, unusual pressure changes. A finding that mean phototactic responses increased when pressure decreased over 9-24-h periods before bioassays is potentially of practical interest. More knowledge about the effects of atmospheric pressure and other environmental variables on behavior can lead to improved models of psyllid movement or other pest management tools as well as to improved timing of application of pest management tools. © Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is witten by US Government employees and is in the public domain in the US. Source

Sattarzadeh A.,Cornell University | Fuller J.,Boyce Thompson Institute for Plant Research | Moguel S.,University of Nebraska - Lincoln | Moguel S.,Union College at Lincoln | And 8 more authors.
Plant Biotechnology Journal

Summary Plastid number and morphology vary dramatically between cell types and at different developmental stages. Furthermore, in C4 plants such as maize, chloroplast ultrastructure and biochemical functions are specialized in mesophyll and bundle sheath cells, which differentiate acropetally from the proplastid form in the leaf base. To develop visible markers for maize plastids, we have created a series of stable transgenics expressing fluorescent proteins fused to either the maize ubiquitin promoter, the mesophyll-specific phosphoenolpyruvate carboxylase (PepC) promoter, or the bundle sheath-specific Rubisco small subunit 1 (RbcS) promoter. Multiple independent events were examined and revealed that maize codon-optimized versions of YFP and GFP were particularly well expressed, and that expression was stably inherited. Plants carrying PepC promoter constructs exhibit YFP expression in mesophyll plastids and the RbcS promoter mediated expression in bundle sheath plastids. The PepC and RbcS promoter fusions also proved useful for identifying plastids in organs such as epidermis, silks, roots and trichomes. These tools will inform future plastid-related studies of wild-type and mutant maize plants and provide material from which different plastid types may be isolated. © 2010 Blackwell Publishing Ltd. Source

Thornton B.J.,Union College at Lincoln | Elthon T.E.,University of Nebraska - Lincoln | Cerny R.L.,University of Nebraska - Lincoln | Siegfried B.D.,University of Nebraska - Lincoln

Atrazine is a widely used herbicide that has been reported to induce the activity of certain detoxification enzymes and to affect insecticide toxicity in organisms experiencing simultaneous exposure to both atrazine and insecticides. In this study, the effects of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) exposure on protein expression in male and female Drosophila melanogaster adults in both microsomal and cytosolic cell fractions was investigated by 2-dimensional gel electrophoresis. Differentially expressed proteins (vs. controls) were identified using matrix assisted laser desorption-time (MALDI-TOF) of flight mass spectrometry (MS). We identified a total of 28 proteins associated with energy production including glycolysis and mitochondrial respiration as differentially expressed and nine proteins associated with detoxification and response to oxidative stress. Most of these proteins were expressed in one sex or the other but not in both. Surprisingly, the only proteins associated with detoxification were identified as glutathione transferases. No cytochrome P450s were identified which have previously been shown to be responsive to atrazine exposure in D. melanogaster and proposed to be associated with insecticide/atrazine interactions. Results of this investigation support the role of atrazine in affecting mitochondrial electron transport and oxidative stress. However, the role of atrazine in pesticide interactions remains uncertain. © 2010 Elsevier Ltd. Source

Fernando J.,Union College at Lincoln | Carlson B.,Union College at Lincoln | LeBard T.,Union College at Lincoln | McCarthy M.,Union College at Lincoln | And 3 more authors.
Journal of Biological Education

The dramatic decrease in the cost of sequencing a human genome is leading to an era in which a wide range of students will benefit from having an understanding of human genetic variation. Since over 90% of sequence variation between humans is in the form of single nucleotide polymorphisms (SNPs), a laboratory exercise has been devised in order to illustrate the importance of SNPs. Two separate SNPs are analysed, one of which has a significant effect on a persons phenotype and one which does not. The genotyping protocol is relatively inexpensive and uses standard molecular biology reagents and equipment. © 2015 Society of Biology. Source

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