(a) Example of the evolutionary chromosomal changes leading, from Hominoidea ancestor (ANC7 and ANC2q), to chromosomes HyA1 and HyA25 in Hylobatidae ancestor. (b) Shows the inversion in ANC13 necessary to derive HyA8 (see text for details). Numbers followed by a letter on the right of chromosomes indicate a specific human BAC as reported in both ST1 and ST5 Supplemental Tables. The numbers on the right of the final Hylobatidae ancestor chromosome (HyA) represent arbitrarily chosen points useful in indicating its composition, as reported in the ST4 Supplemental Table. Usually, they correspond to a BAC, but when found at the borders of the synteny blocks, they identify two BACs facing each other following a rearrangement. The Hylobatidae Ancestral Kayotype (HyAK) is depicted in Fig. 3.
