Functional characterisation of Sirex noctilio chemosensation genes

dc.contributor.advisorSlippers, Bernard
dc.contributor.coadvisorAllison, Jeremy D.
dc.contributor.coadvisorDuong, Tuan A.
dc.contributor.coadvisorPostma, Alisa
dc.contributor.emailleandri.klynsmith@up.ac.zaen_US
dc.contributor.postgraduateKlynsmith, Leandri
dc.date.accessioned2022-05-06T12:04:58Z
dc.date.available2022-05-06T12:04:58Z
dc.date.created2022
dc.date.issued2021-11
dc.descriptionDissertation (MSc (Genetics))--University of Pretoria, 2021.en_US
dc.description.abstractInsects rely on olfaction and gustation to interact with their surrounding environment. The highly sophisticated and complex chemosensory system behind smell and taste has received considerable attention due to its potential to contribute to the development of pest control strategies. This is because elucidating the molecular basis of chemosensation can be exploited in the design of behaviour-modifying chemical molecules. To gain a better understanding of the molecular basis of Sirex noctilio Fabricius (Hymenoptera: Siricidae) chemosensation we used RNA sequencing to create the most comprehensive comparison to date of chemosensation gene expression between olfactory and non-olfactory appendages of this representative of an ancient hymenopteran group. We compared gene expression between 15 transcriptome datasets to identify sex-, tissue-, and developmental stage-specific chemosensation genes. Sirex noctilio has 129 candidate chemosensation genes consisting of 45 olfactory receptors (OR), 12 gustatory receptors (GR), 48 ionotropic receptors (IR), 14 odourant binding proteins (OBP), 9 chemosensory proteins (CSP), and one sensory neuron membrane protein (SNMP). ORs and OBPS were enriched in olfactory appendages whereas GRs, IRs, CSPs, and the SNMP exhibited variable expression profiles across tissues. Developmental stage and tissue type, and to a lesser extent sex, influenced the expression of chemosensory genes. Several differentially expressed genes were identified. The antennae-, ovipositor- and leg-biased chemosensation genes identified are of particular interest due to the olfactory function, oviposition site-selection function and sexual dimorphism of these tissues, respectively. Based on expressed OR transcripts the chemoreceptive spectrum is largely similar between males and females. However, if relative expression levels of ORs correlate with sensitivity then females could have enhanced odour sensitivity. Sex- and tissue-specific genes are promising targets for future deorphanisation studies which could aid the identification of novel attractants or repellents for biorational pest management.en_US
dc.description.availabilityUnrestricteden_US
dc.description.degreeMSc (Genetics)en_US
dc.description.departmentGeneticsen_US
dc.description.sponsorshipDSI-NRF Centre Of Excellence In Plant Health Biotechnologyen_US
dc.description.sponsorshipTree Protection Co-Operative Programmeen_US
dc.identifier.citation*en_US
dc.identifier.otherS2022
dc.identifier.urihttps://repository.up.ac.za/handle/2263/85144
dc.language.isoenen_US
dc.publisherUniversity of Pretoria
dc.rights© 2022 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
dc.subjectChemoreceptorsen_US
dc.subjectChemosensory carrier proteinsen_US
dc.subjectExpression profilingen_US
dc.subjectInvasive insecten_US
dc.subjectOlfactionen_US
dc.subjectSirex noctilioen_US
dc.subjectTranscriptomicsen_US
dc.subjectUCTD
dc.titleFunctional characterisation of Sirex noctilio chemosensation genesen_US
dc.typeDissertationen_US

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