[Identification of aberrant chromosomes based on the morphometry of the synaptonemal complexes in a sterile male...

The synaptonemal complexes (SCs) of surface-spread spermatocytes of male mouse from the F1 progeny of a male exposed to a mutagen have been examined by electron microscopy. Nonreciprocal translocation was recognised in analysing configuration of SC. Electron microscope analysis revealed translocation in 100% pachytene spermatocytes and light microscope analysis of air-dried metaphase spermatocytes demonstrated this in 58% cells. Different types of association of X-chromosome with aberrant chromosomes were discovered in pachytene spermatocytes. Computer analysis of relative length of SCs permits to detect a nonreciprocal translocation from chromosome 4 to chromosome 16. The length of the translocated fragment was determined to be from 66 to 75% of the length of chromosome 4. It has been impossible to discover a telomere fragment of chromosome 16, because the break point of chromosome 16 is too close to the distal end.