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Desiccation physiology of Ceratitis species (Diptera: Tephritidae)
Thesis (PhDConsEcol)--Stellenbosch University, 2023.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2023
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| _version_ | 1867613926057836544 |
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| access_status_str | Open Access |
| author | Bosua, Henrika Jacomina |
| author2 | Terblanche, Jonathan Steed |
| author_browse | Bosua, Henrika Jacomina Terblanche, Jonathan Steed |
| author_facet | Terblanche, Jonathan Steed Bosua, Henrika Jacomina |
| author_sort | Bosua, Henrika Jacomina |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhDConsEcol)--Stellenbosch University, 2023. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/128494 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:43:54.041Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/128494 Desiccation physiology of Ceratitis species (Diptera: Tephritidae) Bosua, Henrika Jacomina Terblanche, Jonathan Steed Weldon, Christopher W. Stellenbosch University. Faculty of AgriSciences. Dept. of Conservation Ecology and Entomology. Ceratitis Tephritidae -- Phylogeny Fruit-flies -- Speciation -- Genetic aspects Fruit-flies -- Geographical distribution Diptera -- Physiology Fruit-flies -- Environmental aspects Insects -- Climatic factors Plant-water relationships Climatic changes UCTD Thesis (PhDConsEcol)--Stellenbosch University, 2023. ENGLISH ABSTRACT: Closely related species from the family Tephritidae (True fruit flies) have different geographic distributions and occupy different climate niches. Several of these species are highly invasive and come to survive and thrive in large parts of the world where they damage fruit and limit fruit trade markets. Therefore, it is that likely that these species have underlying physiological differences that determines the range of environmental conditions they can persist and flourish under. Due to insects having a large surface area to volume ratios, they are prone to losing water and therefore possess a range of mechanisms for coping with desiccating conditions and enabling water homeostasis. This thesis explores three main themes relating to the desiccation physiology of species from the family Tephtritidae. Firstly, the roles that basal and plastic desiccation tolerance play respectively, in species range distribution is explored by comparing metabolic and water loss across four closely related Ceratitis species (Ceratitis capitata, Ceratitis cosyra, Ceratitis podocarpi and Ceratitis rosa), with different geographic ranges. High precision, flow through respirometry measurements were conducted on individual flies to partition total water loss rates into its components and pin-point specific differences between species. The second theme explores how flexibility in metabolic pathways (specifically macronutrient regulation) can offset desiccation stress. Macronutrient oxidations were traced in a desiccation sensitive (Ceratitis rosa) and desiccation tolerant (Ceratitis capitata) species under different environmental conditions (before, during and after desiccation stress). Stable isotope tracers were used to 13C-labbeled body stores of protein, lipid and carbohydrates of these two species. To determine if differential nutrient oxidation can lead to a beneficial survival response, both longevity and nutrient oxidation rates were compared between these two species. The third theme explored concerns the underlying genetic variation and differential gene expression that drives phenotypic plasticity. As Ceratitis capitata has shown a remarkable flexibility in desiccation response that leads to a significant survival benefit, a full mRNA sequencing along with lipidomic profile was conducted on this species to determine if genes related to desiccation traits are differentially expressed. A transcriptomic and lipidomic analysis during desiccation and heat stress, as well gene expression after recovery from stress was explored in this species. A range of metabolic pathways were identified as where differential gene expression correlated with observed phenotypic changes. This thesis contributes to our current understanding of how physiological mechanisms interact with environmental factors to determine a species success in a specific environment. The results and conclusions are discussed in in terms of how changing climates that impact water availability in large areas could affect population dynamics of pest species. AFRIKAANSE OPSOMMING: Naverwante spesies uit die familie Tephritidae (Ware vrugtevlieë) het verskillende geografiese verspreidings en beslaan verskillende klimaatnisse. Verskeie van hierdie spesies is indringer pes spesies en kan oorleef en floreer in groot dele van die wêreld waar hulle vrugte beskadig en vrugtehandelmarkte beperk. Dus is dit waarskynlik dat hierdie spesies onderliggende fisiologiese verskille het, wat dan die omgewingstoestande waaronder hulle kan leef bepaal. Aangesien insekte 'n groot liggaams-oppervlakte tot liggaams-volume verhoudings het, is hulle geneig om water na die omgewing te verloor en beskik hulle dus oor 'n reeks meganismes om uitdroogtoestande te hanteer en waterhomeostase moontlik te maak. Hierdie tesis ondersoek drie hooftemas wat verband hou met die uitdrogingsfisiologie van spesies uit die familie Tephtritidae. Eerstens word die rolle wat basale en plastiese uitdrogingverdraagsaamheid onderskeidelik in spesieverspreiding speel, ondersoek deur metaboliese en waterverlies eienskappe oor vier naverwante Ceratitis spesies (Ceratitis capitata, Ceratitis cosyra, Ceratitis podocarpi en Ceratitis rosa), met verskillende geografiese reekse te vergelyk. Hoë presisie, vloei deur respirometrie metings is op individuele vlieë uitgevoer om totale waterverliestempo's in sy komponente te verdeel en spesifieke verskille tussen spesies vas te stel. Die tweede tema ondersoek hoe buigsaamheid in metaboliese weë (spesifiek makronutriëntregulering) uitdrogingstres kan verreken. Makronutriënt oksidasies is opgespoor in 'n uitdroging sensitiewe (Ceratitis rosa) en uitdroging verdraagsame (Ceratitis capitata) spesie onder verskillende omgewingstoestande (voor, tydens en na uitdroging stres). Stabiele isotoopsporers is gebruik om ¹³C-gemerkte liggaamswinkels van proteïen, lipied en koolhidrate van hierdie twee spesies te gebruik. Om te bepaal of differensiële voedingstofoksidasie tot 'n voordelige oorlewingsreaksie kan lei, is beide langlewendheid en voedingstofoksidasietempo's tussen hierdie twee spesies vergelyk. Die derde tema wat ondersoek word, handel oor die onderliggende genetiese variasie en differensiële geenuitdrukking wat fenotipiese plastisiteit dryf. Aangesien Ceratitis capitata 'n merkwaardige buigsaamheid in uitdrogingsreaksie getoon het wat lei tot 'n beduidende oorlewingsvoordeel, is 'n volledige mRNA-volgordebepaling saam met lipidomiese profiel op hierdie spesie uitgevoer om te bepaal of gene verwant aan uitdrogingseienskappe differensieel uitgedruk word. 'n Transkriptomiese en lipidomiese analise tydens uitdroging en hittestres, asook geenuitdrukking na herstel van stres is in hierdie spesie ondersoek. 'n Reeks metaboliese weë is geïdentifiseer as waar differensiële geenuitdrukking korreleer met waargenome fenotipiese veranderinge. Hierdie tesis dra by tot ons huidige begrip van hoe fisiologiese meganismes in wisselwerking met omgewingsfaktore inwerk om 'n spesiesukses in 'n spesifieke omgewing te bepaal. Die resultate en gevolgtrekkings word bespreek in terme van hoe veranderende klimate wat die beskikbaarheid van water in groot gebiede beïnvloed, die bevolkingsdinamika van plaagspesies kan beïnvloed. Doctoral 2023-03-07T06:24:17Z 2023-08-30T13:11:07Z 2023-03 2023-03-07T06:24:17Z 2023-08-31T09:18:52Z 2023-03-07T06:24:17Z 2023-08-31T09:18:52Z 2023-03 Thesis https://scholar.sun.ac.za/handle/10019.1/128494 en Stellenbosch University application/pdf 118 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Ceratitis Tephritidae -- Phylogeny Fruit-flies -- Speciation -- Genetic aspects Fruit-flies -- Geographical distribution Diptera -- Physiology Fruit-flies -- Environmental aspects Insects -- Climatic factors Plant-water relationships Climatic changes UCTD Bosua, Henrika Jacomina Desiccation physiology of Ceratitis species (Diptera: Tephritidae) |
| title | Desiccation physiology of Ceratitis species (Diptera: Tephritidae) |
| title_full | Desiccation physiology of Ceratitis species (Diptera: Tephritidae) |
| title_fullStr | Desiccation physiology of Ceratitis species (Diptera: Tephritidae) |
| title_full_unstemmed | Desiccation physiology of Ceratitis species (Diptera: Tephritidae) |
| title_short | Desiccation physiology of Ceratitis species (Diptera: Tephritidae) |
| title_sort | desiccation physiology of ceratitis species diptera tephritidae |
| topic | Ceratitis Tephritidae -- Phylogeny Fruit-flies -- Speciation -- Genetic aspects Fruit-flies -- Geographical distribution Diptera -- Physiology Fruit-flies -- Environmental aspects Insects -- Climatic factors Plant-water relationships Climatic changes UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/128494 |
| work_keys_str_mv | AT bosuahenrikajacomina desiccationphysiologyofceratitisspeciesdipteratephritidae |