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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Cartografia Genômica e Evolução em Drosophila sturtevanti Duda, 1927 (grupo saltans)

MONTE, Evilis da Silva 31 January 2013 (has links)
Submitted by Andre Moraes Queiroz (andre.moraesqueiroz@ufpe.br) on 2015-04-14T14:38:12Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Evilis da Silva Monte.pdf: 1778277 bytes, checksum: 32ce58e371b16f1861c19808c2c73f9f (MD5) / Made available in DSpace on 2015-04-14T14:38:12Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Evilis da Silva Monte.pdf: 1778277 bytes, checksum: 32ce58e371b16f1861c19808c2c73f9f (MD5) Previous issue date: 2013 / CNPq / A disponibilidade de 12 genomas sequenciados de espécies do gênero Drosophila enfatizou a importância da citogenética, incluindo a construção de fotomapas dos cromossomos politênicos de outras espécies do gênero. Esta ferramenta é relevante para a localização de genes, detecção de diversidade genética entre populações e para a verificação de inferências evolutivas. A proposta deste trabalho foi de ampliar os estudos citogenéticos no gênero Drosophila, através da construção do fotomapa dos cromossomos politênicos e mapeamento gênico em Drosophila sturtevanti, devido à escassez de dados citogenéticos do grupo saltans. Para a preparação do fotomapa foi utilizada a linhagem DIR (Dois Irmãos, Recife) coletada no Campus da UFRPE em 2009. O fotomapa mostrou que o complemento cromossômico é constituído por cinco braços eucromáticos. O par I é submetacêntrico, representado pelos braços XL e XR, o par II é metacêntrico representado pelos braços IIL e IIR e o cromossomo III é acrocêntrico. Foram observadas duas diferentes inversões paracêntricas, uma no braço XL e outra no cromossomo III. Para os genes Hsp70 e Hsp83 foram identificadas apenas uma marcação relevante, no cromossomo III (seção 86) e no braço XR (seção 32), respectivamente. Os resultados encontrados possibilitaram a comparação do genoma de D. sturtevanti com o genoma de outras espécies e, ainda, sugerem a homologia cromossômica entre os grupos saltans, willistoni e melanogaster.
2

Identificação, caracterização e estudo da expressão dos genes hsc70 e hsp83 em Rhynchosciara americana / Identification, characterization and study of expression of the genes hsc70 and hsp83 in Rhynchosciara americana

Andrade, Alexandre de 19 August 2005 (has links)
Com a idéia de identificar proteínas envolvidas no processo de enovelamento das proteínas sintetizadas na glândula salivar de Rhynchosciara americana, no início deste projeto adotou-se como estratégia o seqüenciamento de uma biblioteca de cDNA. Esta biblioteca foi construída utilizando-se glândulas salivares de Rhynchosciara americana do período de seu desenvolvimento onde tem início a síntese de seu casulo. Mensagens de proteínas envolvidas no processo de enovelamento, transporte e proteólise foram isoladas, alguns exemplos são hsc70, hsp83, hip, hop, dnaJ, trap1 e prolil isomerase, sec61α/β, sec23, peptidase de sinal, rab7, partícula reconhecedora de sinal (srp), enzima conjugadora de ubiquitina e complexo regulatório proteassomo 26, cop 1 e ubiquitina ligase. A identificação destes genes permitiu o isolamento de clones genômicos através de triagem em banco de fagos e caracterização dos genes hsc70 e hsp83 para verificação de sua organização em Rhynchosciara americana. A expressão dos seus respectivos mRNAs foi avaliada em vários períodos do último estágio larval. A localização por hibridização in situ mostrou que estes genes estão localizados em regiões dos cromossomos politênicos próximas a dois pufes de DNA, C3 e C8. O estudo dos níveis de expressão das proteínas codificadas pelos genes hsc70 e hsp83 mostrou a diferença de comportamento destes genes sob condições de estresse térmico e que a expressão destas proteínas deve ser regulada pelo período de desenvolvimento das larvas de Rhynchosciara americana. Quando evidenciada por imunofluorescência a proteína Hsc70 mostra localização predominantemente no citoplasma. / With the idea of identify some of these proteins involved in the folding process of the proteins synthesized on the Rhynchosciara salivary gland, this project started adopting the shotgun cDNA sequencing strategy. This cDNA library was constructed utilizing salivary glands of Rhynchosciara americana at a developmental period where the cocoon construction begins. Messengers of important proteins involved in the folding, transport and proteolysis process were isolated, some examples are hsc70, hsp83, hip, hop, sec61 α/β, sec23, signal peptidase, rab7, signal recognition particle (srp), ubiquitin conjugating enzyme e 26 proteasome regulatory complex, cop 1 and ubiquitin ligase. Identification of these genes allowed the screening of genomic clones from a phage library; hsc70 and hsp83 characterization was carried out to verify the arrangement of these genes on genome of Rhynchosciara americana. The study of these genes will contribute with phylogenetic information about the specie. The mRNA expression of these genes was analyzed during several periods of the last larval developmental stage. In situ localization showed that these genes are located in polytene chromosomes regions near two DNAs puffs, C3 and C8. The expression levels of the proteins codified by genes hsc70 and hsp83 showed different behaviors of these genes under heat stress conditions and mainly, that the regulation of the proteins Hsc70 and Hsp83 can be related to the period of development of the larvae of Rhynchosciara americana. When revealed by immunofluorescence, Hsc70 protein shows localization predominantly on the cytoplasm.
3

Identificação, caracterização e estudo da expressão dos genes hsc70 e hsp83 em Rhynchosciara americana / Identification, characterization and study of expression of the genes hsc70 and hsp83 in Rhynchosciara americana

Alexandre de Andrade 19 August 2005 (has links)
Com a idéia de identificar proteínas envolvidas no processo de enovelamento das proteínas sintetizadas na glândula salivar de Rhynchosciara americana, no início deste projeto adotou-se como estratégia o seqüenciamento de uma biblioteca de cDNA. Esta biblioteca foi construída utilizando-se glândulas salivares de Rhynchosciara americana do período de seu desenvolvimento onde tem início a síntese de seu casulo. Mensagens de proteínas envolvidas no processo de enovelamento, transporte e proteólise foram isoladas, alguns exemplos são hsc70, hsp83, hip, hop, dnaJ, trap1 e prolil isomerase, sec61α/β, sec23, peptidase de sinal, rab7, partícula reconhecedora de sinal (srp), enzima conjugadora de ubiquitina e complexo regulatório proteassomo 26, cop 1 e ubiquitina ligase. A identificação destes genes permitiu o isolamento de clones genômicos através de triagem em banco de fagos e caracterização dos genes hsc70 e hsp83 para verificação de sua organização em Rhynchosciara americana. A expressão dos seus respectivos mRNAs foi avaliada em vários períodos do último estágio larval. A localização por hibridização in situ mostrou que estes genes estão localizados em regiões dos cromossomos politênicos próximas a dois pufes de DNA, C3 e C8. O estudo dos níveis de expressão das proteínas codificadas pelos genes hsc70 e hsp83 mostrou a diferença de comportamento destes genes sob condições de estresse térmico e que a expressão destas proteínas deve ser regulada pelo período de desenvolvimento das larvas de Rhynchosciara americana. Quando evidenciada por imunofluorescência a proteína Hsc70 mostra localização predominantemente no citoplasma. / With the idea of identify some of these proteins involved in the folding process of the proteins synthesized on the Rhynchosciara salivary gland, this project started adopting the shotgun cDNA sequencing strategy. This cDNA library was constructed utilizing salivary glands of Rhynchosciara americana at a developmental period where the cocoon construction begins. Messengers of important proteins involved in the folding, transport and proteolysis process were isolated, some examples are hsc70, hsp83, hip, hop, sec61 α/β, sec23, signal peptidase, rab7, signal recognition particle (srp), ubiquitin conjugating enzyme e 26 proteasome regulatory complex, cop 1 and ubiquitin ligase. Identification of these genes allowed the screening of genomic clones from a phage library; hsc70 and hsp83 characterization was carried out to verify the arrangement of these genes on genome of Rhynchosciara americana. The study of these genes will contribute with phylogenetic information about the specie. The mRNA expression of these genes was analyzed during several periods of the last larval developmental stage. In situ localization showed that these genes are located in polytene chromosomes regions near two DNAs puffs, C3 and C8. The expression levels of the proteins codified by genes hsc70 and hsp83 showed different behaviors of these genes under heat stress conditions and mainly, that the regulation of the proteins Hsc70 and Hsp83 can be related to the period of development of the larvae of Rhynchosciara americana. When revealed by immunofluorescence, Hsc70 protein shows localization predominantly on the cytoplasm.
4

Análise in silico da HSP83 de Leishmania chagasi : implicações para antigenicidade e evolução

Kelle de Araújo Barbosa, Pedranne January 2005 (has links)
Made available in DSpace on 2014-06-12T18:06:34Z (GMT). No. of bitstreams: 2 arquivo6314_1.pdf: 1402240 bytes, checksum: 3a6b521eb7d3cff5b8fb4e3b2347a3ec (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Protozoários flagelados do gênero Leishmania são transmitidos para mamíferos através da picada de insetos flebotomíneos e são os agentes etiológicos das quatro formas clínicas de leishmanioses: leishmaniose visceral que é fatal quando não tratada, leishmaniose mucocutânea, leishmaniose cutânea e a leishmaniose cutânea difusa. A leishmaniose visceral é comum em países em desenvolvimento, com uma estimativa de 500.000 novos casos a cada ano. A Leishmania chagasi é o agente etiológico da leishmaniose visceral nas Américas e outras espécies são responsáveis pela forma visceral da doença no Velho Mundo. Devido sua importância, o desenvolvimento de drogas e vacinas usando antígenos do parasito têm sido o alvo de muitos estudos. Entre os maiores antígenos do parasito estão as proteínas de choque térmico (HSP), a maior classe de proteínas conservadas, classificadas como chaperonas. Elas são essenciais no controle do ciclo celular e estão envolvidas na assistência ao dobramento e prevenção de reações irreversíveis tais como agregações inespecificas de proteíans celulares. As HSP possuem um papel importante com agente imunoregulatório com potente uso terapeutico; ademais elas foram identificadas como os maiores imunógenos em várias doenças infecciosas e que estimulam uma resposta específica protetora. A HSP83, ortóloga a HSP90 de mamíferos, é uma das proteínas de Leishmania mais abundantes e é reconhecida pela resposta imune humoral e celular em humanos e em cães com leishmaniose visceral. Neste estudo, baseado em alinhamentos, a estrutura primária da HSP83 de Leishmania chagasi foi comparada a HSP90 de outros organismos, para investigação de suas relações filogenéticas. Quando a seqüência de aminoácidos foi alinhada às seqüências depositadas no banco de genes públicos, ficou evidente que a proteína é extremamente conservada mesmo em organismos pertencentes a diferentes reinos. Quando a seqüência codificante foi comparada, foi possível mapear rigorosamente os exons do gene humano, exceto pela presença de três gaps. O primeiro gap corresponde a uma alça flexível entre duas folhas beta, o segundo tem 57aa (o maior gap), compreende o domínio N-terminal correspondendo ao sítio de ligação de ATP e o último gap, que corresponde também a uma alça flexível entre o domínio central e o domínio carboxi. O aumento da divergência na seqüência é coincidente com as regiões equivalentes as junções dos exons na proteína ortóloga de mamíferos. Nossos resultados sugerem que o gene da HSP83 dos organismos ancestrais aos Kinetoplastida tinha introns, e que foram perdidos durante a evolução.
5

Estudos sobre a manutenção dos telômeros durante o ciclo de desenvolvimento de Leishmania amazonensis

Vieira, Marina Roveri January 2019 (has links)
Orientador: Maria Isabel Nogueira Cano / Resumo: A leishmaniose é uma doença crônica, causada por parasitos flagelados do gênero Leishmania, podendo se apresentar nas formas clínicas, tegumentar (cutânea), mucocutânea e visceral (calazar). A doença é considerada negligenciada pela OMS, pois não existem até o momento métodos eficientes de tratamento e controle para a mesma. Os telômeros desse parasito são um dos potenciais alvos no desenvolvimento de novos fármacos para o combate dessa doença e, para tanto, é necessário o entendimento da biologia desta estrutura. Uma enzima de grande interesse para o estudo dos telômeros é a telomerase que é a responsável pela manutenção e elongação dessas estruturas nos terminais dos cromossomos. A manutenção dos telômeros não é unicamente regulada pelo complexo ribonucleoproteico (RNP) da telomerase, mas também por proteínas que se associam ao complexo e ao DNA telomérico, tornando a ação do complexo mais efetiva e estável. Até o momento, o complexo telomérico de Leishmania amazonensis é o melhor caracterizado dentre os tripanosomatídeos, porém pouco se sabe sobre a biogênese e a composição do complexo RNP telomerase deste parasito. HSP83, ortólogo da HSP90 humana em Leishmania é uma chaperona altamente conservada, dependente de ATP e expressa quando as células são submetidas a diferentes tipos de estresse estando envolvida em transdução de sinal, crescimento, diferenciação celular e sobrevivência. Também é de grande importância para patógenos humanos, em particular aqueles cujo ciclo de v... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Leishmaniasis is a chronic disease, caused by flagellated parasites of the genus Leishmania, which could be present in different clinical forms such as, tegumentar (cutaneous), mucocutaneous and visceral (kalazar). WHO classifies leishmaniasis as a neglected disease since there are no efficient methods for disease treatment and control. Parasites telomeres are one of the potential targets for the development of new anti-parasitic drugs to combat this disease and, thus, it is necessary to understand the biology of this structure. Telomerase is the enzyme responsible for maintaining and replicating these structures at the chromosomes termini. However, telomeres maintenance is not only regulated by the telomerase ribonucleoprotein complex (RNP), but also by proteins that associate with the complex and with telomeric DNA, making the action of the complex more effective and stable. To date, the telomeric complex of Leishmania amazonensis is the best characterized among trypanosomatids, although little is known about the biogenesis and composition of the RNP telomerase complex of this parasite. HSP90 is a highly conserved, ATP dependent chaperone and expressed when cells are subjected to different types of stress. It is also involved in signal transduction, growth, cell differentiation and survival of the chaperonin is of great importance for human pathogens, particularly those transmitted by insects to a mammalian host, and which suffer from environmental changes such as temperatu... (Complete abstract click electronic access below) / Mestre
6

Análise genômica e pós-genômica de proteínas de Leishmania chagasi

Paula Pimentel Cassilhas, Ana January 2004 (has links)
Made available in DSpace on 2014-06-12T15:53:23Z (GMT). No. of bitstreams: 2 arquivo5113_1.pdf: 974357 bytes, checksum: 6213145f95044915b06cd604154e3c5b (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2004 / As leishmanias são parasitas intracelulares que causam um amplo espectro de doenças, desde lesões cutâneas isoladas até formas viscerais fatais. Apesar dos progressos na epidemiologia, imunologia e bioquímica destas parasitoses. As primeiras 10.000 seqüências de cDNA de Leishmania chagasi, produzidas pelo Programa Genoma Nordeste (ProGeNE), foram analisadas quanto à categorização funcional e conteúdo GC de seqüências codificantes e nãocodificantes, além de ter sido identificado um grupo de genes restritos aos tripanosomatídeos. Foram também analisados dois genes conservados, hsp70 (proteína de choque térmico de 70kDa) e hsp83, que apresentavam seqüência completa. Polipeptídeos recombinantes contendo seqüências de HSP70 progressivamente maiores foram usados em ensaios de imunoadsorção para identificar regiões antigênicas em toda a extensão da proteína. As seqüências de aminoácidos deduzidas para HSP70 e HSP83 foram comparadas com um grande grupo de seqüências similares entre os tripanosomatídeos e entre outros grupos taxonômicos. Os epitopos ou regiões antigênicas, definidos neste estudo mapearam claramente sobre as regiões divergentes. Os sítios precisos de transencadeamento e poli-adenilação para HSP83 foram identificados através de estudos comparativos das regiões 5´- e 3´-não traduzida e das seqüências genômicas correspondentes de HSP83 e de outros genes disponíveis para L. chagasi. Este trabalho espera contribui, portanto, para um melhor entendimento da antigenicidade das HSP nas infecções e para uma definição dos sítios de processamento do RNAm em Leishmania
7

Δομή, έκφραση και λειτουργική ανάλυση του θερμοεπαγόμενου γονιδίου hsp83 της μεσογειακής μύγας, Ceratitis capitata. / Structure, expression and functional analysis of heat shock gene hsp83 of the mediterranean fruit fly, Ceratitis capitata.

Θεοδωράκη, Μαρία 22 June 2007 (has links)
Με στόχο την απομόνωση του γονιδίου hsp83 της μεσογειακής μύγας, πραγματοποιήθηκε διαλογή μιας cDNA βιβλιοθήκης από προνύμφες 3ου σταδίου, με ανιχνευτή το δεύτερο εξώνιο του hsp83 ομόλογου γονιδίου της Drosophila auraria. Από τη διαλογή αυτή προέκυψαν αρκετοί αλληλεπικαλυπτόμενοι κλώνοι, ο μεγαλύτερος των οποίων (CM-1) είχε μέγεθος 2.593 kb και περιελάμβανε ένα ανοιχτό αναγνωστικό πλαίσιο 715 αμινοξέων, από τη μετάφραση του οποίου προκύπτει ένα πολυπεπτίδιο προβλεπόμενου μοριακού βάρους 81,74 kDa. Η προβλεπόμενη αμινοξική αλληλουχία έδειξε πολύ μεγάλη ταυτότητα με όλα τα μέλη της οικογένειας HSP90 και ειδικότερα με τις HSP83 ομόλογες πρωτεΐνες της Drosophila. Επιπλέον, η προβλεπόμενη αμινοξική αλληλουχία περιείχε όλες τις συντηρημένες περιοχές των μελών της οικογένειας των HSP90 και στο καρβοξυτελικό της άκρο, έφερε το πενταπεπτίδιο MEEVD, το οποίο είναι χαρακτηριστικό όλων των κυτταροπλασματικών ισομορφών αυτής της οικογένειας. Με βάση αυτά τα αποτελέσματα ο κλώνος CM-1, ονομάστηκε Cchsp83. Ο κλώνος αυτός, εκτός από ολόκληρη την κωδική περιοχή του γονιδίου, περιείχε μέρος της 5’ μη μεταφραζόμενης περιοχής και ολόκληρη την 3’ μη μεταφραζόμενη περιοχή του hsp83 γονιδίου της μεσογειακής μύγας. Ανάλυση κατά Southern σε γονιδιωματικό DNA με διάφορα ένζυμα περιορισμού και κατάλληλους cDNA ανιχνευτές, έδειξε ότι το Cchsp83 γονίδιο υπάρχει σε ένα μόνο αντίγραφο στο γονιδίωμα της μεσογειακής μύγας. Ανάλυση “Northern” έδειξε την ύπαρξη ενός μεταγράφου με μέγεθος 2,7 kb περίπου. Το Cchsp83 γονίδιο, χαρτογραφήθηκε με in situ υβριδοποίηση σε μία θερμοεπαγόμενη χρωμοσωματική διόγκωση των πολυταινικών χρωμοσωμάτων των σιελογόνων αδένων του εντόμου (6R:94C). Η μελέτη του προτύπου έκφρασης του γονιδίου Cchsp83 έγινε σε επίπεδο RNA με RT-PCR σε ολικό RNA και σε επίπεδο πρωτεΐνης με ανάλυση Western σε ολικά πρωτεϊνικά εκχυλίσματα. Αντισώματα για την CcHSP83 αναπτύχθηκαν μετά από έκφραση ενός σημασμένου με 6 His τμήματος του Cchsp83 cDNA (490-690aa) σε βακτήρια E. coli. Η αντίδραση του Cchsp83 γονιδίου στην αύξηση της θερμοκρασίας είναι πολύ γρήγορη και ευαίσθητη. Μετάγραφα του γονιδίου ανιχνεύονται μετά από 5 λεπτά θερμικού στρες και σε θερμοκρασίες αρκετά χαμηλές (300C). Η επαγωγή του γονιδίου γίνεται μέγιστη μετά από 30-60 λεπτά θερμικού στρες στους 37-390C. Η επαναφορά της έκφρασης του γονιδίου στα φυσιολογικά επίπεδα μετά από θερμικό στρες είναι αργή, αφού για να γίνει αυτό απαιτούνται 4 ώρες ανάκαμψης στους 250C, μετά από μόλις 30 λεπτά θερμικού στρες στους 380C. Αναπτυξιακή μελέτη του προτύπου έκφρασης του Cchsp83 έδειξε ότι το γονίδιο εκφράζεται σε όλη τη διάρκεια της ανάπτυξης της μεσογειακής μύγας. Στους 250C τόσο τα επίπεδα του RNA, όσο και τα επίπεδα της πρωτεΐνης, είναι υψηλά στα εμβρυικά στάδια, χαμηλά στα προνυμφικά και μέτρια στα νυμφικά και ενήλικα στάδια. Μετά από θερμικό στρες στους 380C, τα επίπεδα των μεταγράφων αυξάνονται αρκετά, ιδιαίτερα στα στάδια που σε φυσιολογικές συνθήκες είναι χαμηλά. Όσον αφορά στα επίπεδα της πρωτεΐνης, τα αποτελέσματα ήταν παρόμοια μετά από θερμικό στρες στους 350C, αλλά όχι στους 37-390C, όπου δεν παρατηρήθηκε καθόλου επαγωγή. Το γεγονός αυτό υποδηλώνει ότι σε υψηλές θερμοκρασίες καταστέλλεται η ωρίμανση ή και η μετάφραση του Cchsp83 RNA. Με στόχο την απομόνωση των ρυθμιστικών περιοχών του γονιδίου Cchsp83 της μεσογειακής μύγας, πραγματοποιήθηκε διαλογή μιας χρωμοσωματικής λEMBL-4A βιβλιοθήκης, με ανιχνευτή το δεύτερο εξώνιο του hsp83 ομόλογου γονιδίου της Drosophila auraria. Από τη διαλογή αυτή απομονώθηκαν δύο κλώνοι, ένας από τους οποίους περιελάμβανε μέρος της κωδικής περιοχής, την 5’ μη μεταφραζόμενη περιοχή και 3,5 kb της 5’ ανοδικής περιοχής του γονιδίου Cchsp83. Σύγκριση της γονιδιωματικής αλληλουχίας με τη cDNA αλληλουχία, αποκάλυψε την ύπαρξη ενός μικρού εσωνίου 275 bp ανάμεσα στην 5’ μη μεταφραζόμενη περιοχή και στην αρχή της κωδικής περιοχής του γονιδίου. Βιοπληροφορική ανάλυση και πειράματα 5’ RACE, υποδηλώνουν ότι το σημείο έναρξης της μεταγραφής του γονιδίου βρίσκεται 144 bp ανοδικά του 5’ άκρου του εσωνίου και 23 bp καθοδικά ενός τυπικού στοιχείου TATA (ΤΑΤΑΑΑΤΑ). Δύο πιθανά στοιχεία απόκρισης στη θερμοκρασία (HSEs) εντοπίστηκαν στην εγγύς 5’ περιοχή του γονιδίου, 35 και 330 bp ανοδικά του στοιχείου TATA. Επιπλέον, βρέθηκαν 4 ακόμα πιο απομακρυσμένα HSEs, 1.595, 2.861, 2.880 και 2.890 bp, ανοδικά του σημείου έναρξης της μεταγραφής, καθώς και ένα HSE μέσα στο εσώνιο. Λειτουργική ανάλυση της εγγύς 5’ ανοδικής περιοχής του γονιδίου Cchsp83 πραγματοποιήθηκε με τη μέθοδο του γενετικού μετασχηματισμού. Τρία αλληλεπικαλυπτόμενα τμήματα του υποκινητή του γονιδίου Cchsp83, μήκους 519 bp (-380/+139, PL), 230 bp (-86/+144, PM) και 193 bp (-55/+139, PS) τοποθετήθηκαν μπροστά από το γονίδιο αναφοράς lacZ και εισήχθησαν στο γονιδίωμα της μεσογειακής μύγας με το σύστημα μετασχηματισμού Minos. Η έκφραση του γονιδίου αναφοράς, ελέγχθηκε σε όλες τις διαγονιδιακές σειρές που προέκυψαν με την ποσοτική ενζυματική μέθοδο της β-γαλακτοζιδάσης. Οι PM-lacZ και PS-lacZ σειρές δεν έδειξαν ανιχνεύσιμα επίπεδα έκφρασης του lacZ γονιδίου τόσο σε φυσιολογικές συνθήκες, όσο και σε συνθήκες θερμικού στρες. Αντιθέτως, οι περισσότερες από τις PL-lacZ σειρές έδειξαν σημαντικά επίπεδα συστατικής έκφρασης. Το αναπτυξιακό πρότυπο έκφρασης του γονιδίου αναφοράς μελετήθηκε σε μία PL-lacZ σειρά και βρέθηκε παρόμοιο με εκείνο του ενδογενούς γονιδίου, υποδηλώνοντας ότι η -380/+139 περιοχή του υποκινητή περιλαμβάνει όλα τα ρυθμιστικά στοιχεία που απαιτούνται για την ορθή χρονική έκφραση του Cchsp83 γονιδίου σε φυσιολογικές συνθήκες. Αν και η περιοχή αυτή του υποκινητή περιλαμβάνει δύο δυνητικά στοιχεία απόκρισης στη θερμοκρασία καθώς και την 5’ UTR, εντούτοις δεν είχε την ικανότητα να οδηγήσει σε θερμοεπαγόμενη έκφραση το γονίδιο αναφοράς. Τα αποτελέσματά μας υποδεικνύουν ότι η περιοχή -380/+139 του Cchsp83 γονιδίου μπορεί να χρησιμοποιηθεί για την ανάπτυξη διαγονιδιακών συστημάτων σήμανσης της μεσογειακής μύγας, τα οποία αναμένεται να συμβάλλουν στη διατήρηση και ανίχνευση κατάλληλων στελεχών που χρησιμοποιούνται σε προγράμματα βιολογικού ελέγχου του επιβλαβούς αυτού εντόμου. / By using the second exon of the D. auraria hsp83 gene as a probe, a number of overlapping cDNA clones were isolated from a Ceratitis capitata (medfly) cDNA library. The longest cDNA had a size of 2,593 bp and contained an open reading frame coding for a putative polypeptide of 715 amino acids with a predicted molecular weight of 81.74 kDa. In addition, it contained a part of the 5’-untranslated region and the complete 3’-untranslated region of a medfly hsp83 homolog, named Cchsp83. The predicted amino acid sequence showed a high degree of identity to all known sequences of the HSP90 family and was more closely related to the Drosophila HSP83 homologs. The putative medfly HSP83 contained all the conserved sequences of the members of the HSP90 family and was ended, at the C-terminal, with the pentapeptide MEEVD that characterizes all the cytosolic members of this family. Genomic Southern blot analysis, with several restriction enzymes and appropriate cDNA probes, indicated that the Cchsp83 gene exists as a single copy in the medfly genome. Northern blot hybridization revealed a single transcript of approximately 2.7 kb. In situ hybridization analysis showed that the Cchsp83 gene maps at the 94C region of the 6th chromosome (6R:94C), which corresponds to one of the major heat shock puffs of the medfly salivary gland polytene chromosomes. Evaluation of the Cchsp83 gene transcript and protein levels was performed by RT-PCR and western analysis, using total RNA and protein from synchronized animals. Anti-HSP83 antibodies were prepared against a histidine tag purified chimeric polypeptide from E. coli cells, transformed with a part of the coding region (aa 490-690) of the Cchsp83 cDNA. The response of the Cchsp83 gene to heat was fast and sensitive. Heat-induced transcript levels could be detected within 5 min at temperatures as low as 300C. Maximum transcript levels were obtained after 30-90 min treatments at 35-390C. Following recovery at 250C, after a 30 min heat shock, the accumulated transcripts remained at high levels for approximately 3h and declined to the non-induced levels 1h later. Developmental studies showed that the Cchsp83 gene is expressed constitutively throughout medfly development. At 250C, both transcript and protein levels were high in embryonic stages, low in larval stages and moderate in pupal and adult stages. Following heat shock at 380C, the transcript levels increased approximately 3- to 5-fold, depended on the developmental stage. Similar results were obtained for the protein levels after a heat shock at 350C, but not at 380C, suggesting that the Cchsp83 mRNAs are not translated efficiently at high temperatures. Screening of a genomic λEMBL-4A library from 24-h-old medfly embryos with the second exon of the D. auraria hsp83 gene, resulted in the isolation of a genomic clone containing part of the coding region, the untranslated leader region (5’ UTR) and 3.5 kb from the 5’ flanking region of the gene. Comparison of the genomic and cDNA nucleotide sequences revealed the presence of a small intron of 275 bp between the 5’ untranslated and coding regions of the gene. Thus the Cchsp83 gene is organized into two exons separated by a small intron. Computational analysis and 5’ RACE experiments, suggested that the putative transcription initiation site of the gene is located 144 bp upstream of the 5’ splicing site of the intron and 23 bp downstream of a typical TATA box (TATAΑΑΤΑ). Two putative heat shock elements (HSEs) were identified in the proximal 5’ flanking region of the gene, 35 and 330 bp, upstream of the TATA box. In addition to them, four distal HSEs, 1,595, 2,861, 2,880 and 2,890 bp, upstream of the putative transcription initiation site and one HSE inside the intron were identified. Functional analysis of the proximal 5’ flanking region of the Cchsp83 gene was performed by germline transformation. Three overlapping promoter fragments PL (-380/+139), PM (-86/+144) and PS (-55/+139), were fused to the lacZ reporter gene and the resulting constructs were introduced into the medfly genome via Minos-element mediated germline transformation. The expression of the reporter gene, in at least 8 homozygous transformed lines for each construct, was evaluated by quantitative β-galactosidase assays. The PM-lacZ and PS-lacZ lines did not show detectable levels of lacZ expression at neither normal or heat shock conditions. On the other hand, most of the PL-lacZ lines showed significant levels of constitutive lacZ expression. Developmental expression studies in one of these lines showed that the reporter gene exhibited similar developmental expression pattern to the endogenous one, suggesting that the PL promoter region includes all the necessary regulatory elements for driving correct temporal expression of the Cchsp83 at normal conditions. Although this promoter region contained the two proximal HSEs and the 5’ UTR, it was unable to drive heat-induced expression of the reporter gene suggesting that additional upstream and/or downstream sequences are necessary for the heat-induced expression of the Cchsp83 gene. Our data indicate that the PL promoter region of the Cchsp83 gene can be used as a driver for the development of robust transgenic marker systems in medfly. Such systems are important for detecting, maintaining and recognizing medfly strains that are used today in population control programs of this agricultural pest.

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