Impairment of Figure-Ground and Shape Discrimination After Lesion of Nucleus Subpretectalis in Pigeons

Mentors: Olga Lazareva and Martin AcerboOur earlier research has shown that nucleus rotundus, a thalamic nucleus processing visual information in pigeons, together with its inhibitory complex, is differentially activated in birds performing figure-ground discrimination, color discrimination, and shape discrimination (Acerbo, McInnerney, et al., in preparation). In this study, we conducted bilateral chemical lesions of nucleus subpretectalis, a major inhibitory nucleus that regulates activity of nucleus rotundus but does not process visual information directly. We trained pigeons to simultaneously perform three visual discriminations (figureground, color, and shape) using the same displays. When birds learned to perform all three tasks at high levels of accuracy, we conducted the bilateral lesions of n. subpretectalis using ibotenic acid. After a period of recovery, the birds were retrained on the same tasks to evaluate the effect of lesion on maintenance of discriminations. Preliminary results indicate that lesion of nucleus subpretectalis has no effect on color discrimination, and impairs both shape and figure-ground discrimination. These results suggest that figure-ground segregation in avian brain may occur at the level of thalamus, rather than at the cortical level as it does in primates.Drake University, College of Arts & Sciences, Department of Psycholog

Using Empathetic Design Thinking to Fuel Your Learning Experience Designs

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Empathetic Design Thinking to Fuel your Learning Experience Design

Based on the workshop, “Empathetic Design Thinking to Fuel your Learning Experience Design” presented at the OLCwELD Spring 2017 Conference, this emerging trends article looks to define design thinking and share a model that educators, instructional/learning designers, and other stakeholders can reproduce and adapt in their respective organizations and institutions

Effects of 15-Acetyl-deoxynivalenol (15-ADON) and Diacetoxyscirpenol (DAS) Mycotoxins on Tribolium castaneum

Two major threats to stored products in the United States and throughout the world are stored product insects and contamination from mycotoxins, which are secondary metabolites produced by fungi, such as Fusarium spp. (Glenn, 2007). Although stored product insects are not associated with negative health impacts when consumed by humans or animals, mycotoxins can negatively impact fertility, reproductive health, growth and development, particularly in livestock (Brake, 1999). Unfortunately, it is difficult to remove mycotoxins from contaminated products and most products have to be destroyed. However, stored product insects routinely feed on products contaminated by mold and may posses detoxification enzymes that could be exploited by the food industry to degrade mycotoxins. To determine whether Tribolium castaneum (red flour beetles) may have resistance to mycotoxins commonly encountered in stored products, such as 15-acetyl-deoxynivalenol (15-ADON) and diacetoxyscirpenol (DAS), we performed bioassays using 10-fold serial dilutions of both purified toxins independently and measured life history parameters, including mortality rates, growth rates, and progeny production. These parameters were compared to insects fed on a control diet to determine whether mycotoxins negatively impacted red flour beetle adults. This allows for an understanding of how individual mycotoxins influence the insects rather than their combinations seen in naturally contaminated mold (Guo, 2014).The results showed no significant impact on any of the life history parameters from the 15-ADON mycotoxin; however, the DAS showed a significant impact on growth rates and progeny production. Furthering the study of the resistance of red flour beetles to mycotoxins may allow us to discover novel enzymes that could be used to degrade mycotoxins contaminating grain, allowing it to be used as animal food and reducing post-harvest losses

Behavioral responses of Tribolium castaneum to mycotoxin contaminated wheat

Red flour beetles are major pests of stored grains throughout the world. Since the females can lay up to 300-400 eggs in their lifetime, an infestation can get out of control quickly (Brown et al, 2009). Although ingestion of stored product insects is not associated with any major health risks to humans or animals, infested products can have a pungent odors and are often unsuitable for consumption (Smith et al, 1971). To understand what may attract the beetles to a food source, we tested to see how they would react to mycotoxin deoxynivalenol (DON), a common mycotoxin found in stored grains that have been contaminated with mold (Sobrova et al, 2010). Red flour beetles routinely feed on grain that has been contaminated with mold; however, it is unknown if red flour beetles follow volatile cues from mold to find food sources. This research is to find out if red flour beetles are attracted to wheat that has been contaminated with the mycotoxin deoxynivalenol (DON). The results show that the male beetles avoided the mycotoxin and that the females show neither an attraction or an avoidance of the volatile. Ultimately, identifying compounds that attract or repel stored product insects can help us develop novel behaviorally based-strategies to prevent insects from locating food sources

Microbial Communities Associated With Stable Fly (Diptera: Muscidae) Larvae and Their Developmental Substrates

Bacteria are essential for stable fly (Stomoxys calcitrans (L.)) larval survival and development, but little is known about the innate microbial communities of stable flies, and it is not known if their varied dietary substrates influence their gut microbial communities. This investigation utilized 454 sequencing of 16S and 18S amplicons to characterize and compare the bacterial and eukaryotic microbial communities in stable fly larvae and their developmental substrates. The microbial community of the third-instar stable fly larvae is unambiguously distinct from the microbial community of the supporting substrate, with bacterial communities from larvae reared on different substrates more similar to each other than to the communities from their individual supporting substrates. Bacterial genera that were more abundant proportionally in larvae compared to their substrates were Erysipelothrix, Dysgonomonas, Ignatzschineria (Gammaproteobacteria), and Campylobacter (Epsilonprotobacteria). The alphaproteobacteria Devosia, Brevundimonas, Sphingopyxix, and Paracoccus were more abundant proportionally in field substrates compared to their larvae. The main genera responsible for differences between the positive and negative field substrates were Dysgonomonas and Proteiniphilum. In contrast to Dysgonomonas, Proteiniphilum was more abundant in substrate than in the larvae. A large number of sequences were assigned to an unclassified protest of the superphylum Alveolata in larvae and their substrate. Microscopy validated these findings and a previously undescribed gregarine (phylum Apicomplexa, class Conoidasida) was identified in stable fly larvae and adults

Green Bug Aphid Genome

I studied the greenbug aphid (Shizaphis graminum), which has been recognized as a pest of grain crops and grasses for over 150 years and was first reported in North America in 1882 (University of Florida, Featured Creatures). In warm climates, most insects are female and they reproduce via parthenogenesis (Kansas State University, Sorghum Insects). Greenbugs are agriculturally important because they can feed on over 70 different species of plants. The basis for this project was to attempt to improve the greenbug aphid genome assembly using in order to better understanding its biology and why it have different host plants unlike other aphids. The question was, can we use sequencing data generated from 10X Chromium to improve scaffolding of the existing assembly? The results show that we did in fact improve the genome scaffolding using BWA and ARCS. These results are important because improving the genome allows us compare the greenbug genome to other aphids and measure gene expression (mRNA levels) as it feeds different plants to understand why it has such a broad host range

Functional genomics and microbiome profiling of the Asian longhorned beetle (\u3ci\u3eAnoplophora glabripennis\u3c/i\u3e) reveal insights into the digestive physiology and nutritional ecology of wood feeding beetles

Background: Wood-feeding beetles harbor an ecologically rich and taxonomically diverse assemblage of gut microbes that appear to promote survival in woody tissue, which is devoid of nitrogen and essential nutrients. Nevertheless, the contributions of these apparent symbionts to digestive physiology and nutritional ecology remain uncharacterized in most beetle lineages. Results: Through parallel transcriptome profiling of beetle- and microbial- derived mRNAs, we demonstrate that the midgut microbiome of the Asian longhorned beetle (Anoplophora glabripennis), a member of the beetle family Cerambycidae, is enriched in biosynthetic pathways for the synthesis of essential amino acids, vitamins, and sterols. Consequently, the midgut microbiome of A. glabripennis can provide essential nutrients that the beetle cannot obtain from its woody diet or synthesize itself. The beetle gut microbiota also produce their own suite of transcripts that can enhance lignin degradation, degrade hemicellulose, and ferment xylose and wood sugars. An abundance of cellulases from several glycoside hydrolase families are expressed endogenously by A. glabripennis, as well as transcripts that allow the beetle to convert microbe-synthesized essential amino acids into non-essential amino acids. A. glabripennis and its gut microbes likely collaborate to digest carbohydrates and convert released sugars and amino acid intermediates into essential nutrients otherwise lacking from their woody host plants. Conclusions: The nutritional provisioning capabilities of the A. glabripennis gut microbiome may contribute to the beetles’ unusually broad host range. The presence of some of the same microbes in the guts of other Cerambycidae and other wood-feeding beetles suggests that partnerships with microbes may be a facilitator of evolutionary radiations in beetles, as in certain other groups of insects, allowing access to novel food sources through enhanced nutritional provisioning

Microbial Communities Associated With Stable Fly (Diptera: Muscidae) Larvae and Their Developmental Substrates

Bacteria are essential for stable fly (Stomoxys calcitrans (L.)) larval survival and development, but little is known about the innate microbial communities of stable flies, and it is not known if their varied dietary substrates influence their gut microbial communities. This investigation utilized 454 sequencing of 16S and 18S amplicons to characterize and compare the bacterial and eukaryotic microbial communities in stable fly larvae and their developmental substrates. The microbial community of the third-instar stable fly larvae is unambiguously distinct from the microbial community of the supporting substrate, with bacterial communities from larvae reared on different substrates more similar to each other than to the communities from their individual supporting substrates. Bacterial genera that were more abundant proportionally in larvae compared to their substrates were Erysipelothrix, Dysgonomonas, Ignatzschineria (Gammaproteobacteria), and Campylobacter (Epsilonprotobacteria). The alphaproteobacteria Devosia, Brevundimonas, Sphingopyxix, and Paracoccus were more abundant proportionally in field substrates compared to their larvae. The main genera responsible for differences between the positive and negative field substrates were Dysgonomonas and Proteiniphilum. In contrast to Dysgonomonas, Proteiniphilum was more abundant in substrate than in the larvae. A large number of sequences were assigned to an unclassified protest of the superphylum Alveolata in larvae and their substrate. Microscopy validated these findings and a previously undescribed gregarine (phylum Apicomplexa, class Conoidasida) was identified in stable fly larvae and adults

\u3ci\u3eWheat streak mosaic virus\u3c/i\u3e alters the transcriptome of its vector, wheat curl mite (\u3ci\u3eAceria tosichella Keifer\u3c/i\u3e), to enhance mite development and population expansion

Wheat streak mosaic virus (WSMV; genus Tritimovirus; family Potyviridae) is an economically important wheat virus that is transmitted by the wheat curl mite (WCM; Aceria tosichella Keifer) in a persistent manner. Virus–vector coevolution may potentially influence vector gene expression to prolong viral association and thus increase virus transmission efficiency and spread. To understand the transcriptomic responses of WCM to WSMV, RNA sequencing was performed to assemble and analyse transcriptomes of WSMV viruliferous and aviruliferous mites. Among 7291 de novo-assembled unigenes, 1020 were differentially expressed between viruliferous and aviruliferous WCMs using edgeR at a false discovery rate ≤0.05. Differentially expressed unigenes were enriched for 108 gene ontology terms, with the majority of the unigenes showing downregulation in viruliferous mites in comparison to only a few unigenes that were upregulated. Protein family and metabolic pathway enrichment analyses revealed that most downregulated unigenes encoded enzymes and proteins linked to stress response, immunity and development. Mechanistically, these predicted changes in mite physiology induced by viral association could be suggestive of pathways needed for promoting virus–vector interactions. Overall, our data suggest that transcriptional changes in viruliferous mites facilitate prolonged viral association and alter WCM development to expedite population expansion, both of which could enhance viral transmission