| Popis: |
Heterologous monoclonal antibodies E2 (against rat cytokeratin 8) and OSC-1 (against cytoskeletal preparations of mouse oocytes) were used to study the presence and distribution of cytokeratins in Xenopus oocytes during their maturation and growth. To improve visualization of cytokeratins, more adequate methods of oocyte fixation and processing were developed. The results on distribution of cytokeratins obtained with the above mentioned antibodies were compared with one another and with published data. It was found that data obtained by different authors, who used different types of antibodies and different methods for fixation and visualization of Xenopus oocyte cytokeratins, are often contradictory and inconsistent. Along with that, common features of cytokeratin distribution are revealed that have been noticed by every author: animal-vegetal asymmetry of cytokeratin distribution and the existence of two keratin domains, cortical and ooplasmic ones. Specific for the cortical domain of the animal hemisphere is the arrangement of filaments in parallels to the surface, whereas filaments of the ooplasmic domain are oriented radially. The vegetal hemisphere is characterized by the presence of a network formed by filaments with different orientation. We also describe certain peculiarities of cytokeratin distribution in previtellogenic oocytes, as well as disintegration of the keratin system by the end of oocyte maturation. |
