Chiasma interference maps (CHIMs) of mouse chromosomes. Chiama interference maps (CHIMs) for spermatocyte (upper) and oocyte (lower) chromosome rank sizes with the centromeric heterochromatin situated to the left. Single chiasmata are represented by vertical red bars, crossing the axis with distal clusters projected outside the axis. Multiple chiasmata within each bivalent are joined by loops, illustrating the chiasma interference patterns. Loops joining extreme proximal and interstitial chiasmata are shown in green, and those joining extreme distal and interstitial ones in blue. Loops joining extreme proximal and extreme distal chiasmata are black and those joining two interstitially located chiasmata are red. Note the wider distribution of interstitial chiasmata in comparison to the corresponding, near terminal ones in multiple chiasma bivalents. Revised from .