Cytogenet Cell Genet 87:182–188 (1999) Evolutionary disruptions of human syntenic groups 3, 12, 14, and 15 in Ateles paniscus chamek (Platyrrhini, Primates) F.C. Canavez, a M.A.M. Moreira, b C.R. Bonvicino, b P. Parham, a and H.N. Seua ´ nez b, c a Department of Structural Biology, Stanford University School of Medicine, Stanford, CA (USA); b Genetics Section, Instituto Nacional de Câncer, Rio de Janeiro (Brazil); and c Department of Genetics, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil) Supported by the Instituto Nacional de Câncer, Fundaça ˜o Ary Frauzino, Fundaça ˜o O Botica ´ rio de Proteça ˜o à Natureza, and Fundaça ˜o de Amparo a Pesquisa do Estado do Rio de Janeiro (Brazil), and by Grant No. AI 31168 from the National Institutes of Health. Received 2 July 1999; revision accepted 3 September 1999. Request reprints from Dr. Héctor N. Seua ´ nez, Genetics Section, Instituto Nacional de Câncer, Praça da Cruz Vermelha, 23, 20230-130 Rio de Janeiro, RJ (Brazil); telephone: +55-21-506-6209; e-mail: genetics@inca.org.br. ABC Fax + 41 61 306 12 34 E-mail karger@karger.ch www.karger.com © 2000 S. Karger AG, Basel 0301–0171/99/0874–0182$17.50/0 Accessible online at: www.karger.com/journals/ccg Abstract. Comparative gene assignments of 18 markers, based on analyses of somatic cell hybrids and previous data in the literature, indicated that human (HSA) syntenic groups 3, 12, 14, and 15 are dissociated in the spider monkey species Ateles paniscus chamek (APC). Markers present in HSA 3p were allocated to APC 3 and APC 9. The HSA 12 cluster was split into two syntenic groups, one mainly including HSA 12p markers in APC 16 and the other, including HSA 12q markers, in APC 2p. The HSA 14q cluster split into three syntenic groups, corresponding to APC 2q, APC 6, and APC 12. Finally, the HSA 15 cluster split into two syntenic groups, APC 2q and APC 3. Comparisons with previous gene assignments and human SROs led to the tentative postulation of rearrangements having occurred during the evolutionary divergence of man and A. paniscus chamek. Chromosome painting data in the congeneric species A. geoffroyi, other New World and Old World primates, and several representative non-primate ani- mals were compared in an attempt to delineate the ancestral and derived conditions underlying the evolutionary rearrange- ment of syntenic groups in mammals. Copyright © 2000 S. Karger AG, Basel Different extents of karyotypic rearrangements have taken place during the phyletic radiation of mammals, resulting in disparate syntenic assortments among mammalian orders (O’Brien et al., 1988). Thus, while rodents are extremely shuf- fled, karyotypic evolution in the primates has been more con- servative, except in selected groups where rearrangements have been prominent, as in the case of gibbons (among Old World primates) and of owl, howler, and spider monkeys (among New World primates). Among the 15 or 16 extant genera of New World (neotropi- cal) primates, the genus Ateles (2n = 32/34) was shown to be greatly rearranged by karyotypic comparison with species be- longing to other primate genera, including man (Turleau et al., 1974; Seua ´ nez et al., 1993). This was later demonstrated by gene assignment with primate × rodent cell hybrid panels showing numerous disruptions of evolutionary conserved syntenic clus- ters and de novo associations in Ateles paniscus chamek (2n = 34; Seua ´ nez et al., 1994, 1997; Moreira et al., 1997; Canavez et al., 1998, 1999). Moreover, in the karyotypically similar congen- eric species A. geoffroyi (2n = 34), chromosome painting with human whole-chromosome probes (Morescalchi et al., 1997) clearly showed a high amount of karyotypic shuffling that was congruent with the syntenic associations previously described in A. paniscus chamek. Taken together, these studies supported the proposition that Ateles is a very derived primate lineage, as dem- onstrated by cladistic analyses of DNA sequences of the Â-globin, Á 1 -globin, and interstitial retinol-binding protein genes (Meireles et al., 1995; Schneider et al., 1996).