Intermediate filament proteins immunologically related to cytokeratins in the oocyte of the fish Cyprinus carpio.

We have used monoclonal antibodies specific for different sets of human cytokeratins and the anti-IFA (Intermediate Filament Antigen) antibody to investigate the expression of intermediate filament proteins in the mature oocyte of the teleost Cyprinus carpio. Several polypeptides have been identified, showing molecular weights ranging from 43 to 65 kDa. Two-dimensional analysis of the immunoreactive species revealed the presence of at least six major protein spots and a series of minor components, grouped in quite a narrow pI range from 5.52 to 6.28. The general complexity of the carp oocyte cytokeratin-related cytoskeleton appears to be higher than those described for oocytes of other vertebrate species.