Wolbachia distribution and cytoplasmic incompatibility during sperm development: the cyst as the basic cellular unit of CI expression.

The growth and distribution of the intracellular microbe Wolbachia pipientis during spermatogenesis in several different host/symbiont genetic combinations in Drosophila melanogaster and Drosophila simulans is described. Considerable intra- and inter-strain variation in Wolbachia density and tissue distribution was observed. Wolbachia were found inside spermatocytes and spermatids or within the somatic cyst cells surrounding the germ cells. Some strains displayed both tissue distributions. High rates of cytoplasmic incompatibility (CI) are correlated with high levels of Wolbachia only when spermatocytes and/or spermatids harbor the microbe. Wolbachia infection of somatic cyst cells, although sometimes present at high levels, did not result in significant CI expression. CI-inducing Wolbachia strains within D. simulans showed no distinguishable differences in distribution or density within infected spermatids. To dissect the relative contribution of host and symbiont to the expression of CI, Wolbachia from various host strains known to exhibit varying levels of CI were introgressed into new uninfected host genetic backgrounds. These introgression experiments confirm that the mod(+)/mod(-) phenotype is an intrinsic Wolbachia trait and is not determined by host factors. The level of sperm modification in those lines harboring Wolbachia capable of modifying sperm, however, is influenced by host genetic background. These results form the basis of the Wolbachia Infected Spermatocyte/Spermatid Hypothesis (WISSH). According to WISSH, Wolbachia infection in spermatocytes and then spermatids during sperm development is required for CI expression.

Ureaplasma urealyticum infection and apoptosis of spermatogenic cells.

AIM: To study the relationship between Ureaplasma urealyticum (UU) infection and apoptosis of human spermatogenic cells. METHODS: Spermatogenic cells were observed under light microscope with Wright-Giemsa staining and by means of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick-end labeling (TUNEL) technique. RESULTS: Apoptotic rate of UU-infected males (15.5% +/- 6.8%) was significantly higher than that of controls (5.2% +/- 2.3%). CONCLUSION: Apoptosis of spermatogenic cells can be caused by UU infection, which provides further evidence for UU-induced male infertility.

Detection of porcine reproductive respiratory syndrome virus by the polymerase chain reaction.

A polymerase chain reaction (PCR) is described for the detection of the porcine reproductive respiratory syndrome virus (PRRSV). Using the PCR we were able to detect about 30 infectious units of PRRSV resolved in tissue culture medium or sperm. For the detection of PRRSV in sperm the PCR is 10-times more sensitive than culturing in alveolar macrophages. For the detection of PRRSV, PCR provides a good alternative to cell culture methods.

An ultrastructural study of vertical transmission of Rickettsia tsutsugamushi during oogenesis and spermatogenesis in Leptotrombidium pallidum.

Rickettsia tsutsugamushi in Leptotromibidium pallidum was observed by electron microscopy and rickettsiae were found in the various tissues and organs of both larvae and adults. Budding of rickettsiae, a manner of release from the host cells, was observed only in the rudiments of the reproductive organs in larvae. Oogonia and maturing oocytes in adult females and eggs after oviposition contained the microorganisms. In adult males, rickettsiae were also found in the spermatogonia, spermatocytes, and spermatids in the early stage of spermatogenesis, but were eliminated from these cells during maturation. Only the maturing spermatids, but not the eliminated rickettsiae, migrated to another rickettsia-free area of the testis, resulting in the separation of spermatids from rickettsiae and in the production of rickettsia-free spermatophores. Based on these observations, the mechanism of vertical transmission of the rickettsiae to the progeny occurs only in the female parents. Most rickettsiae in the somatic cells of larvae and adults were coccoid, but some rickettsiae in the ovary and the testis of adult mites showed bacillary forms and were enveloped by a membrane of unknown origin.

Virus-host studies in human seminal and mouse testicular cells.

Virological studies were performed for male infertility and repeated abortions. It was found that in about 40% of infertile males infectious adeno- or herpes simplex virus is present in the semen, while the same viruses are present in 60% of the cells in a latent form. In the aborted fetuses the same viruses could be observed as in the father's cells. Due to semen added to tissue cultures the latent presence also of other viruses could be supposed. The affinity of adeno- and herpes viruses to urogenital organs was confirmed by animal experiments, where a new method was applied for in vivo infection. The close correlation between viruses and urogenital cells was similarly confirmed by infecting in vitro human seminal and testicular cells with adeno- and herpes simplex viruses absorbed by the cells, entering them, moreover replicating in the form of their components. Based on the results, it was assumed that chronic local urogenital infections, due to various viruses, may play a role in male infertility and in a part of repeated abortions by damaging their cells. Applying a Zovirax therapy, the seminal cells were stopped to be viral carriers and normal function was restored.

[Sexual transmission of the tick-borne encephalitis virus in ixodid ticks (Ixodidae)]. / Polovaia peredacha virusa kleshchevogo éntsefalita u iksodovykh kleshchei (Ixodidae).

Sexual transmission of tick-borne encephalitis virus from infected ixodid males to noninfected females is shown: in Ixodes persulcatus in 50% (6 of 12) and in Hyalomma anatolicum in 6.2% (1 of 16). The sexual transmission of tick-borne encephalitis virus is shown to provide a transmissible transfer of the virus into eggs in ixodid ticks. Electron microscope studies of the sexual system of ixodid males infected with the virus have revealed numerous morphologically mature virus particles in lumens of endoplasmic reticulum, in vacuoles of Golgi complex of spermatocytes and in association with tubular elements of spermatids.

Sexual transmission of spotted fever group rickettsiae by infected male ticks: detection of rickettsiae in immature spermatozoa of Ixodes ricinus.

Electron microscopic evidence is provided showing that the newly described "Swiss agent," a spotted fever group rickettsia, is incorporated into the reproductive cells of its male tick vector, Ixodes ricinus. Rickettsiae were found in spermatogonia, spermatocytes, and maturing spermatids. The potential significance of these observations is briefly discussed in relation to published data on sexual transmission of rickettsiae by ticks.