An ultrastructural and immunocytochemical study of rat male germ cells at different stages of development has been carried out. Investigation of morphological changes of spermatogenic cells showed the presence of close associations between chromatoid bodies (CBs) and other cell organelles, particularly with the nucleus and Golgi apparatus. In addition, a connection of manchette noncentosomal microtubules (MTs) with spermatid perinuclear ring plasma membrane (PM) in the zone of adhesion intercellular contact, zonula adhaerens (ZA), was revealed. These results, as well as the available literary data, make it possible to analyze expected pathways of noncentrosomal MT nucleation in the late spermatids. It is possible to suggest that noncentorosomal MT are nucleated on the sites of perinuclear ring ZA. The immunocytochemical anal ysis revealed two novel proteins for these cells: BASP1 and MARCKS. It was shown that these proteins were present in CBs in early spermatids. During spermatozoid differentiation, these proteins are located along the outer dense fibers (ODFs) of the sperm tail. BASP1 and MARCKS are believed to be involved in the processes of calcium accumulation in CBs and ODFs. Calcium ions seem to play a significant role in RNA processing and protein synthesis in spermatids. Calcium is also necessary for sperm mobility defined mainly by ODFs.

No abstract

Гибель клеток в результате генетически запрограммированных процессов апоптоза принимает участие не только в эмбриогенезе и гистогенезе, но также является фактором патогенеза многих заболеваний, в том числе вызываемых факторами окружающей среды, и может индуцироваться ими. В последнее время на первый план вышли исследования молекулярных механизмов апоптоза. В настоящем обзоре основное внимание уделено современным данным об ультраструктурных особенностях основных клеточных органелл и об их изменениях в процессе апоптоза, в том числе перестройкам компонентов интерхроматинового пространства ядра, а также участию убиквитин-протеасомной системы в апоптозе. Ключевые слова: апоптоз, внутриклеточные органеллы, ультраструктура, хроматин, электронная микроскопия, убиквитин-протеасомная система. Cell death caused by the genetically determined processes known as apoptosis is implicated not only in embryogenesis and cell and tissue turnover but also in the pathogenesis of many diseases including those induced by environmental factors and may be directly induced by some of the latter. In recent years, the elucidation of the molecular mechanisms of apoptosis was taking the central stage as reflected in a numerous reviews. The present review is focused on recent data about the ultrustructural features of cellular organelles upon apoptosis, including first of all the rearrangements of the interchromatin intranuclear space and the involvement of the ubiquitin-proteasome system in apoptosis.