Cytogenetic studies of oocyte fusion products.
We describe for the first time the cytogenetic characteristics of mouse 'embryos' obtained by oocyte fusion (oocyte fusion products; OFP). Our results indicate that, after fusion, meiosis II is resumed correctly, with extrusion of two haploid polar bodies, and that metaphase synchronisation of the two haploid sets and chromosome segregation during the first cleavage are also normal.