An apparent differential use of the two arms of HX in mouse and rat. Through several breakages and inversions, HX can be transformed to five fragments of MX as well as five fragments of RX (numerically numbered in blocks as MX1, MX2, or RX1, RX2...). Specifically, HXp corresponds to three fragments of MX (the last 20 Mb, a middle 17 Mb, and the start 16 Mb), and to two middle fragments of RX. HXq corresponds to three fragments of RX (the last 78 Mb, a middle 9 Mb, and the start 12 Mb), and to two middle fragments of MX. Blocks with the same fragment number in both mouse and rat are indicated with the same color (e.g., MX1 and RX1 are both represented as white blocks). Block sizes are somewhat arbitrary and do not reflect the actual fragment length. MX1: 3-19 Mb, MX2: 19.3-61, MX3: 80-63, MX4: 80-130, MX5a: 133-130, and MX5b: 150-135. RX1: 12-0.8, RX2: 29-12, RX3: 38-29, RX4a: 42-40, RX4b: 44-82, RX5a: 82-129, and RX5b: 132-160 (fragment ranges are all in Mb).
