RESUMO
Metacestodes of Hymenolepis diminuta secrete a molecule that decreases vitellogenin (Vg) synthesis in the beetle host, Tenebrio molitor. The 5608 bp T. molitor Vg cDNA represents a single-copy gene encoding a single open reading frame of 1821 amino acids with a predicted molecular mass of 206 kDa. Northern blot analysis revealed detectable levels of transcripts only in adult females. In vivo, Vg mRNA abundance was significantly higher in fat bodies from infected females compared with control females at all but the earliest time point. In vitro, Vg mRNA abundance was significantly increased in fat bodies incubated with live stage I-II parasites. The apparent conflict between increased Vg mRNA abundance and decreased Vg protein in fat bodies from infected females is discussed.
Assuntos
Secreções Corporais/metabolismo , Regulação da Expressão Gênica , Hymenolepis/metabolismo , RNA Mensageiro/metabolismo , Tenebrio/genética , Tenebrio/parasitologia , Vitelogeninas/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Southern Blotting , Primers do DNA , DNA Complementar/genética , Corpo Adiposo/metabolismo , Feminino , Interações Hospedeiro-Parasita , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Tenebrio/metabolismo , Vitelogeninas/genéticaRESUMO
Current techniques for the genetic engineering of insect genomes utilize transposable genetic elements, which are inefficient, have limited carrying capacity and give rise to position effects and insertional mutagenesis. As an alternative, we investigated two site-specific integration mechanisms in the yellow fever mosquito, Aedes aegypti. One was a modified CRE/lox system from phage P1 and the other a viral integrase system from Streptomyces phage phi C31. The modified CRE/lox system consistently failed to produce stable germline transformants but the phi C31 system was highly successful, increasing integration efficiency by up to 7.9-fold. The ability to efficiently target transgenes to specific chromosomal locations and the potential to integrate very large transgenes has broad applicability to research on many medically and economically important species.
Assuntos
Aedes/genética , Engenharia Genética/métodos , Genoma de Inseto , Animais , Bacteriófagos , Marcação de Genes , Vetores Genéticos , Integrases , Transdução Genética , Proteínas Virais , Integração ViralRESUMO
The presence of immune molecules induced by microorganisms in the haemolymph of Lutzomyia longipalpis sandflies has been investigated. Injections of Escherichia coli and Micrococcus luteus into female sandflies induced anti-bacterial activity in the haemolymph. Inhibition zone assays showed that haemolymph from E. coli and M.luteus injected sandflies differentially inhibited M.luteus growth. This differential effect was specific to M.luteus infection since anti-E.coli activity was similar in haemolymph from both E.coli or M.luteus injected sandflies. Haemolymph following injection of either bacteria showed the induction of a 4 kDa peptide. Haemolymph from M.luteus injected sandflies also contained a 33 kDa polypeptide which was absent in haemolymph from E.coli and control uninfected insects. Sandflies, in common with other insects, were shown to possess general and specific humoral immune responses to the presence of microorganisms.
