Infection of the gonads of the SimES strain of Drosophila simulans by the hereditary reovirus DSV.

The S character of Drosophila simulans SimES-st strain undergoes a non-mendelian transmission. It has been postulated that a virus, Drosophila S virus (DSV), could be the causative agent. Electron microscopy analysis of gonads of flies showing a strong S phenotype revealed the presence of virus in or near the germ cells. The S character transmission rate is greater in females than that in males. Similarly, the level of infection by DSV is higher in ovaries than that in testes. Flies treated at a nonpermissive temperature do not present the S phenotype and appear to be cured from the virus. This information, taken together with previous work, makes the hypothesis that DSV is the causative agent of the S phenotype more than likely.