RESUMO
Using an in vitro development system for Plasmodium berghei sporogonic stages and microarray technology we examined parasite gene expression during ookinete invasion of Aedes cells and the ensuing oocyst development. A number of genes were found to be differentially expressed. The most prominent class of up-regulated elements corresponded to products involved in protein synthesis and metabolism. Furthermore, several previously studied genes with a known in vivo developmental profile matched published data. A large number of genes with a hitherto unknown function during the life cycle stages studied also show a differential pattern of expression, indicating the involvement of their products in control and execution of active developmental processes.
Assuntos
Culicidae/parasitologia , Perfilação da Expressão Gênica , Expressão Gênica , Genes de Protozoários , Plasmodium berghei/genética , Animais , Células Cultivadas , Análise por Conglomerados , Técnicas de Cocultura , Culicidae/citologia , Metabolismo Energético , Células Epiteliais/parasitologia , Estágios do Ciclo de Vida , Análise de Sequência com Séries de Oligonucleotídeos , Plasmodium berghei/crescimento & desenvolvimento , Biossíntese de Proteínas/genéticaRESUMO
Plasmodium berghei and Plasmodium chabaudi are widely used model malaria species. Comparison of their genomes, integrated with proteomic and microarray data, with the genomes of Plasmodium falciparum and Plasmodium yoelii revealed a conserved core of 4500 Plasmodium genes in the central regions of the 14 chromosomes and highlighted genes evolving rapidly because of stage-specific selective pressures. Four strategies for gene expression are apparent during the parasites' life cycle: (i) housekeeping; (ii) host-related; (iii) strategy-specific related to invasion, asexual replication, and sexual development; and (iv) stage-specific. We observed posttranscriptional gene silencing through translational repression of messenger RNA during sexual development, and a 47-base 3' untranslated region motif is implicated in this process.