Cloning and characterization of Echinococcus granulosus (Cestode) EgactI and EgactII actin gene promoters and their functional analysis in the NIH3T3 mouse cell line

Characterizations of Hirudo medicinalis DNA promoters for targeted gene expression

The expression of exogenous genes in neurons and other cells has become a powerful means for studying the function of encoded proteins. We report here on the isolation and functional analysis of three Hirudo medicinalis actin gene promoters and the 5' UTR of a leech elongation factor-1alpha (HmEF-1alpha) gene. In situ hybridization labeling revealed that the EF-1alpha gene and one of the actins had pan-neuronal expression, whereas, the other two actin genes were expressed by the embryo's body wall musculature. Comparative analysis shows that they all display many features typical of actin and EF-1alpha promoters from other species, including canonical TATA box sequences and predicted general transcription factor binding sites (such as CCATT, CarB boxes and CG-rich regions). The ability of these 5' UTR sequences to drive expression of the enhanced green fluorescent protein (EGFP), leech cytoplasmic actin and leech synaptobrevin was examined. Direct intracellular nuclear, but not cytoplasmic, microinjection of each of the promoter sequences was found to produce reliably cellular expression of the reporter construct in both neuronal and muscle cells. These results introduce reliable and effective methods to selectively express genes in individual cells of the leech in vivo during embryonic development.

Recent advances in the immunology and diagnosis of echinococcosis

Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and Echinococcus multilocularis, which cause cystic echinococcosis and alveolar echinococcosis, respectively. Both cystic echinococcosis and alveolar echinococcosis are serious diseases, the latter especially so, with a high fatality rate and poor prognosis if managed inappropriately. This review highlights recent advances in immunity to infection and vaccination against both parasites in their intermediate and definitive hosts and procedures for diagnosis of cystic echinococcosis and alveolar echinococcosis, including the value of immunodiagnostic and DNA approaches. There is discussion also of progress in genomics and related technologies that is providing valuable insights on the functional biology of the Echinococcus organisms. These studies will underpin future research that will reveal a better understanding of the Echinococcus-host interplay, and suggest new avenues for the identification of additional targets for diagnosis, vaccination and chemotherapy.

Gene manipulation in parasitic helminths

In light of recent growth in available DNA sequence information for a number of parasitic helminths, it is crucial that suitable gene manipulation technologies are developed to facilitate functional genomic studies in these organisms. In this review we discuss recent progress in the development of these technologies in nematode and platyhelminth parasites of medical and veterinary importance. Specifically, the current status of transient transfection, double-stranded RNA interference and antisense RNA as viable techniques for the manipulation of parasitic helminth gene expression is presented. In addition, the potential for the development of stable, or germ-line, transformation methods in these organisms is also discussed.