Temperature-dependent gonadal hybrid dysgenesis in Drosophila willistoni

Temperature-dependent gonadal dysgenesis was shown to occur in the progeny of both inter- and intrastrain crosses involving two populations of Drosophila willistoni, one of which was an old laboratory stock, and the other, freshly collected from a natural population. We propose that the phenomenon observed was caused by the mobilization of transposable elements, as occurs in several other Drosophila species.

Echinococcus granulosus recombinant antigens

Echinococcus granulosus is a small parasitic platyhelminth, the larval stage of which is the causative agent of cystic hydatid disease both in man and domestic ungulates. This zoonosis constitutes major economic and public (both human and veterinary) health problems in many parts of the world, including southern Brazil, where it is hyperendemic. Serodiagnosis of cystic hydatid disease has been of great importance in clinical diagnosis, posttreatment surveillance of patients and epidemiólogical surveys, since it is the most specific of the noninvasive alternatives for detecting infections with the E. granulosus metacestode. Nevertheless, immunological tests present chronical problems associated with the quality and availability of parasite antigens. In this sense, the cloning of E. granulosus antigen-encoding genes comes forth as a valuable alternative for the production of pure and well characterized antigens. In the last few years, several research groups have cloned and characterized genes that encode E. granulosus antigens, many of which are potentially useful in the immunodiagnosis of cystic hydatid disease. Furthermore, several of these antigens represent important components of the parasite biology and may be particularly relevant to vaccination, immunotherapy, or as potential targets for chemotherapy. In this review we summarize the available data concerning the production and characterization of E. granulosus recombinant antigens. We also discuss some of the perspectives opened by the use of molecular biology techniques in the diagnosis of cystic hydatid disease as well as in the study of the biology of this parasite.