How the Oocyte Nucleolus Is Turned into a Karyosphere: The Role of Heterochromatin and Structural Proteins.

Oocyte meiotic maturation includes large-scale chromatin remodeling as well as cytoskeleton and nuclear envelope rearrangements. This review addresses the dynamics of key cytoskeletal proteins (tubulin, actin, vimentin, and cytokeratins) and nuclear envelope proteins (lamin A/C, lamin B, and the nucleoporin Nup160) in parallel with chromatin reorganization in maturing mouse oocytes. A major feature of this reorganization is the concentration of heterochromatin into a spherical perinucleolar rim called surrounded nucleolus or karyosphere.

Lupus progression deteriorates oogenesis quality in MRL/lpr mice.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the activation of the immune response against self antigens. Numerous reproductive complications, including reduced birth rate and complications for the mother and the fetus during pregnancy, have been observed in women with SLE. In the present study, we aimed to investigate the effect of SLE development on oocyte meiosis in lupus-prone mice.

Osteoarthritis Affects Mammalian Oogenesis: Effects of Collagenase-Induced Osteoarthritis on Oocyte Cytoskeleton in a Mouse Model.

Known as a degenerative joint disorder of advanced age affecting predominantly females, osteoarthritis can develop in younger and actively working people because of activities involving loading and injuries of joints. Collagenase-induced osteoarthritis (CIOA) in a mouse model allowed us to investigate for the first time its effects on key cytoskeletal structures (meiotic spindles and actin distribution) of ovulated mouse oocytes. Their meiotic spindles, actin caps, and chromatin were analyzed by immunofluorescence.

Defective oogenesis in mice with pristane-induced model of systemic lupus.

Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease characterized by generation of autoantibodies and severe damage of various organs. The hormonal changes associated with pregnancy and especially estrogen might lead to damage of reproductive function and ovarian quality. We employed a pristane-induced lupus model of Balb/c mice which resembles human lupus in an attempt to follow oogenesis disruption during the disease progression.

Prostaglandin F2α Causes Fast Degenerative Changes in Ovulated Mouse Oocytes.

The effects of prostaglandin F2α on the cytoskeleton and membrane organelles of oocytes was investigated by culturing ovulated mouse oocytes in its presence (50 or 100 ng/ml) for 3 h. Tubulin, fibrillar actin, membranes and chromatin were visualized by specific antibodies, phalloidin, lipophilic dye DiOC6 and Hoechst 33342, respectively. Control oocytes were characterized by a meiotic spindle with chromosomes aligned at its equator, and a cortical layer of microfilaments with an actin cap.

Dynamics of Lamins B and A/C and Nucleoporin Nup160 during Meiotic Maturation in Mouse Oocytes.

This study was aimed at elucidating the fate of three important nuclear envelope components - lamins B and A/C and nucleoporin Nup160, during meiotic maturation of mouse oocytes. These proteins were localized by epifluorescence and confocal microscopy using specific antibodies in oocytes at different stages from prophase I (germinal vesicle) to metaphase II. In immature germinal vesicle oocytes, all three proteins were detected at the nuclear periphery.

[Investigation of cytokeratin and vimentin intermediate filaments in polycystic ovaries (PCOS) -- presence and specific structure of Balbiani body in primordial follicles].

Despite of the importance of cytoskeletal proteins for ovarian function and pathology, very few studies have addressed the presence and distribution of these proteins in polycystic ovaries. We investigated sections of human polycystic ovarian tissue for vimentin and a set of cytokeratins by epifluorescence. The studied proteins showed strong colocalization.