Cytological methods for the study of meiotic properties in mice

Cytological methods now available produce excellent preparations of many of the meiotic stages in both male and female mice. Large samples of these stages can be obtained from males, limited samples from females. Some of these stages are useful for the identification of structural heterozygosity. As yet, the potentially valuable stage of pachytene can be used only for looking at specific chromosome bivalents and cannot be used for extensive genome analysis. The later stages of diakinesis and first metaphase have proved most rewarding for study and have enabled us to identify the meiotic configurations resulting from several different kinds of translocations and from paracentric inversions. It is possible, however, that many smaller rearrangements between and within chromosomes escape detection.