S. E. Dixon

University of Guelph

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R. W. Shuel

University of Guelph

Niel A. Karrow

University of Guelph

ÁC

Ángela Cánovas

University of Guelph

Paula Menzies

University of Guelph

Bonnie A. Mallard

University of Guelph

Andrew S. Peregrine

University of Guelph

Emma Borkowski

University of Guelph

Aroa Suárez‐Vega

Universidad de León

H. Lerer

University of Guelph

Peter F. Lue

University of Ottawa

Cooperative Institutions

University of Guelph

Cornell University

Ontario Veterinary College

Agricultural Research Service

University of Arizona

United States Department of Agriculture

Carl Hayden Bee Research Center

University of Saskatchewan

Harvard University

Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria

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THE EFFECT OF JUVENILE HORMONE ON THE FUNCTION OF THE ACCESSORY GLAND OF THE ADULT MALE COCKROACH PERIPLANETA AMERICANA (ORTHOPTERA: BLATTIDAE)

The Canadian Entomologist (1973)

W. D. Blaine S. E. Dixon

Abstract The juvenile hormone was necessary for the sex accessory glands in newly metamorphosed, adult males, to produce a normal amount of spermatophore material. Protein production could be restored to normal in allatectomized newly metamorphosed roaches by implanting adult or nymphal roach corpora allata. In decapitated roaches, the weight of the accessory gland is reduced drastically. The weight of the gland could be increased by implanting adult roach corpora allata, or by injecting juvenile hormone.

Corpus allatum

Blattidae

10.4039/ent1051275-10

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Identification of Long Non-Coding RNAs Linked to Parasite Host Immune Response in Sheep

Aroa Suárez‐Vega S. E. Dixon Niel A. Karrow Paula Menzies Bonnie A. Mallard

Identification

Host response

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149 Differences in Gene Expression Following Natural Exposure to Gastrointestinal Parasites between Sheep Selected for High Innate Responses and High Antibody-Mediated Adaptive Immune Responses

Journal of Animal Science (2022)

Olivia Willoughby Emma Borkowski S. E. Dixon Samla M F Cunha Victoria Asselstine

Abstract Parasitism by gastrointestinal nematodes (GINs) is a major source of morbidity and mortality for sheep flocks grazed on pasture. Since there is evidence for genetic resistance to GINs in some sheep breeds, genetic selection for immunologic resistance to GIN is a possible management strategy. This study sought to identify differences at the transcriptome level between Ridau-Arcott sheep characterized as high innate immune responders (IIRs, n=5) or high antibody-mediated immune responders (AbMIRs, n=5) following natural exposure to and infection with GINs after spending the summer on GIN-infested pasture; infection was confirmed with individual fecal egg counts. The transcriptomes of the high IIR and high AbMIR animals were also compared with GIN-naïve sheep of the same breed (all medium IIR and AbMIR responders, n = 7). Liver tissue samples from the 17 animals were used to perform transcriptomic analyses using RNA-Sequencing technology. The CLC Genomics Workbench 20.0.4 (CLC Bio, Aarhaus, Denmark) software was used to map reads to the most recent ovine reference genome (Oar rambouillet.v1.0.105), and for differential gene expression analysis. In total, 144 differentially expressed genes (DEG) were found between the high IIRs and the high AbMIRs (FDR< 0.05, and fold change (FC) abs > 2). When compared to the naïve animals, 136 and 53 DEG were found between them and the high IIRs and the high AbMIRs, respectively. In order to verify their function in the host immune response to GINs, functional enrichment analyses were performed on these candidate genes using the AmiGO2 software. Monocarboxilic acid metabolism was identified as an enriched biological process (FDR < 0.05), and ammonia-lyase activity and metalloendopeptidase activity were enriched molecular functions between the high IIR and high AbMIR animals (FDR < 0.05). These preliminary results improve understanding of how host resistance to GINs is genetically regulated through the innate and adaptive immune systems in sheep.

10.1093/jas/skac247.138

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Variation in ovine serum vitamin D concentrations from late summer to early spring and during immune challenge with bacterial endotoxin

Veterinary Immunology and Immunopathology (2024)

Stacy B Randle Lauri Wagter-Lesperance S. E. Dixon Umesh K. Shandilya Bonnie A. Mallard

10.1016/j.vetimm.2024.110856

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A TECHNIQUE FOR AGEING COCOONS OF THE SAWFLY NEODIPRION SERTIFER (HYMENOPTERA: DIPRIONIDAE)

The Canadian Entomologist (1971)

Fong-Ching Chai S. E. Dixon

Abstract A technique for ageing cocoons of Neodiprion sertifer (Geoff.) is outlined using the redox dye 2,6-dichloroindophenol. New cocoons reduce 1 ml of a 0.001% solution in 85% ethanol from blue to colorless in 15 minutes. This reducing power diminishes with age.

Sawfly

10.4039/ent10380-1

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Aspects of the metabolism of 10-hydroxy-2-decenoic acid, the natural lipid of honeybee (Apis mellifera L.) larval diet

Canadian Journal of Zoology (1978)

S. E. Dixon R. W. Shuel

The fatty acid unique to the natural diet of honeybee larvae, 10-hydroxy-2-decenoic acid (10-HDA) is not metabolized by the mitochondria but by the microsomal fraction of larval homogenates. The only other fatty acid metabolized was γ-hydroxybutyrate and this by the mitochondria. The rate of 10-HDA oxidation was enhanced by ferrous ion and NADPH.

Royal Jelly

10.1139/z78-085

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HYDROLYZING ENZYME ACTIVITY IN THE BRAIN AND THE RETROCEREBRAL SYSTEM OF THE AMERICAN COCKROACH (PERIPLANETA AMERICANA (L)) WITH SPECIAL REFERENCE TO THE NEUROSECRETORY MATERIALS

Canadian Journal of Zoology (1964)

Yong Shao S. E. Dixon

Some hydrolyzing enzymes have been investigated by histochemical and biochemical methods. Almost all neurons in the brain contain acid phosphatases. About half of the total activity is associated with subcellular particles. Most of the acid-phosphatase activity in the corpora cardiaca (CC) is associated with the neurosecretory materials (NSM). Elementary neurosecretory granules (ENG) have been isolated from the CC by fractionation and subfractionation procedures and subjected to in vitro enzyme activity studies. Electron micrographs of the subfraction having the highest acid-phosphatase activity are discussed in relation to three types or "stages" of ENG. About 80% of the total esterase activity in the brain and the retrocerebral system has been found to be in a "soluble" form. The remaining 20%, the "insoluble" forms, may be associated with subcellular organelles. The methods of Gomori and Burstone for acid-phosphatase localizations are compared, and differing results discussed. The possible roles or functions of acid phosphatases and esterases in the neurosecretory system are discussed.

American cockroach

Organelle

Cell fractionation

Esterase

10.1139/z64-027

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Identifying Hepatic Genes Regulating the Ovine Response to Gastrointestinal Nematodes

S. E. Dixon

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STUDIES IN THE MODE OF ACTION OF ROYAL JELLY IN HONEYBEE DEVELOPMENT: III. THE EFFECT OF EXPERIMENTAL VARIATION IN DIET ON GROWTH AND METABOLISM OF HONEYBEE LARVAE

Canadian Journal of Zoology (1963)

S. E. Dixon R. W. Shuel

Norms were established for respiration, growth, and tissue composition of 0- to 72-hour-old female honeybee larvae reared in the laboratory on natural royal jelly and worker jelly diets. The worker jelly diet was then altered experimentally in the direction of royal jelly through additions of sugar and certain water-soluble acids of unknown structure extracted from royal jelly, but present in the natural diets of larvae of both female castes. In general, developmental norms were shifted in the direction of the norms of larvae fed royal jelly, but the changes were not fully co-ordinated. The added acids were strongly growth inhibitory. A high inverse association between the total water-soluble acid content of the diet and larval weight suggested that the acids may represent a nutritional growth-regulating mechanism. The evidence indicates that nutrient balance is significant in the early development of the dichotomy between female castes, and that no single constituent determines the ultimate development of either caste.

Royal Jelly

10.1139/z63-045

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Quantitative Changes in Dna, Rna and Protein During Early Caste Development in the Female Honeybee

Journal of Apicultural Research (1977)

H. Lerer S. E. Dixon

SummaryThe RNA, DNA and protein contents of queen and worker honeybees between 48 and 96 hours of larval life were determined. Whereas DNA content does not seem to play a part in the initiation of caste, a definite dimorphism between castes was observed with respect to RNA content; this was greater for worker larvae than for queen larvae during the period of caste determination. Queen and worker larvae had similar protein concentrations. The ratio RNA/DNA may represent the capacity for protein synthesis in the whole animal.

Caste

Queen (butterfly)

Sexual dimorphism

10.1080/00218839.1977.11099872

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Citations (2)