Meiotic diagrams and FISH signal patterns in spermatozoa using breakpoint-specific BAC clones. When using specific BAC clones spanning the break points, the in situ mixing of green and red signals gives yellow signals or a combined red/green signal on inverted or recombinant chromosomes, and thus allows the identification of each meiotic product, like (a) normal, (b) inverted, (c) duplicated/deficient, and (d) dicentric.