[Karyosphere and extrachromosomal nuclear bodies in oocytes of the scorpionfly, Panorpa communis].
Oocyte nuclear structures were studied for the scorpionfly Panorpa communis at different stages of oocyte growth, from pachytene to the first meiotic division. Using immunofluorescent and immunogold microscopy, we analyzed the nuclear distribution of RNA polymerase II, splicing factors and coilin. These factors were revealed in close association with perichromatin fibrils and, later, with some elements of the karyosphere and extrachromosomal nuclear bodies (NBs). Besides, it was shown that large amounts of P. communis oocyte NBs represent Cajal bodies (CBs) and contain CB marker protein, coilin, as well as RNA polymerase II, and in some cases an essential splicing factor, SC35. The presence of SC35 is commonly not characteristic of CBs in somatic cells. CB dynamics was traced in inactivated oocyte nuclei, during a gradual condensation of chromosomes and their final assembling into the karyosphere. It has been shown that coilin, RNA polymerase II and SC35 protein are common compounds shared by CBs and some granular material associated with these condensed chromosomes. CB remnants were demonstrated in the ooplasm after the breakdown of nuclear envelope before the first meiotic division. In inactivated oocyte nuclei, CBs serve presumably as storage compartments for some inactive components essential for gene expression.
Batalova
F M
FM
Bogoliubov
D S
DS
Parfenov
V N
VN
D000818:Animals; D022003:Cell Nucleus Structures / Q000378:metabolism / Q000648:ultrastructure*; D002843:Chromatin / Q000378:metabolism; D005260:Female; D007150:Immunohistochemistry; D007313:Insecta / Q000502:physiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D009865:Oocytes / Q000502:physiology / Q000648:ultrastructure*; D012319:RNA Polymerase II / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D014818:Vitellogenesis / Q000502:physiology
D002843:Chromatin; D017411:Ribonucleoproteins, Small Nuclear; D012319:RNA Polymerase II