title: DNA synthesis and distribution in parthenogenetic bovine embryos.
abstract: Parthenogenetically activated, in vitro-matured bovine oocytes and parthenogenotes obtained at 2 to 4 days post activation were analyzed by 3H-thymidine autoradiography for the timing of the S-phase and for distribution of newly replicated DNA, respectively. Spread pronuclear parthenogenotes revealed that the DNA synthesis in electrically stimulated oocytes commenced at 14 h post activation. At 20 to 24 h, a maximum number of labeled pronuclei was reached (25 to 38%), and DNA synthesis persisted in some parthenogenotes up to 30 h post activation. The DNA labeling detected on semi-thin sections showed that the distribution of newly synthesized DNA in the nuclei of 3- to 16-cell parthenogenotes was mostly irregular or abnormal, documenting that the apparent morphological normalcy of parthenogenotes was in contrast to the data concerning the DNA synthesis and distribution.
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídenská 1083,CS 142 20 Prague 4, The Czech Republic.
authors.forename: V
authors.initials: V
authors.lastname: Landa
authors.forename: V
authors.initials: V
authors.lastname: Kopecný