The fate of residual bodies and denegrating germ cells and the lipid cycle in sertoli cells in the bandicoot Perameles nasuta Geoffroy (Marsupialia)

Abstract

After separation from mature spermatids, the residual bodies of the bandicoot move within Sertoli cell cytoplasm towards the basement membrane of the tubule. As the result of a reduction in volume and a condensation of its contents, the residual body is transformed into a rather dense structure, the most obvious constituents of which are tightly packed membranous whorls. The particulate lipid of such a body then increases quite markedly, presumably as a consequence of the degradation of the membranous whorls. Surface projections, some of which consist almost exclusively of particulate lipid, develop and subsequently appear to break away from the main mass of the body. Residual bodies of diminishing size and number persist throughout the rest of the seminiferous cycle, conceivably to give rise to lysosome-like organelles which could be utilized in the digestion of a new generation of residual bodies. A characteristic lamellar inclusion present in spermatogonia and spermatocytes permits a distinction to be made between degenerating forms of these cells and most forms of residual bodies. The initiation of the lipid cycle in bandicoot Sertoli cells does not appear to be strictly correlated with the release of lipid from residual bodies.