Chromosome phylogeny of the subfamily Pitheciinae (Platyrrhini, Primates) by classic cytogenetics and chromosome painting

Our results show that members of the Pitheciinae have conserved several chromosome forms found in the inferred ancestral Platyrrhini karyotype (associations of human homologous segments 3a/21, 5/7a, 2b/16b, 8a/18, 14/15a and 10a/16a). Further, the monophyly of this subfamily is supported by three chromosomal synapomorphies (2a/10b, an acrocentric 15/14 and an acrocentric human 19 homolog). In addition, each species presents several autapomorphies. From this data set we established a chromosomal phylogeny of Pitheciinae, resulting in a single most parsimonious tree.In our chromosomal phylogeny, the genus Pithecia occurred in a more basal position close to the inferred ancestor of Platyrrhini, while C. c. rubicundus and C. utahicki are closely related and are linked by exclusive synapomorphies.The subfamily Pitheciinae includes the genera Pithecia Desmarest, 1804, Chiropotes and Cacajao Lesson, 1840. Pithecia comprises five species: Pithecia pithecia, Pithecia monachus, Pithecia irrorata (each two subspecies), Pithecia albicans and Pithecia aequatorialis (both monotypic) [1]. Chiropotes is represented by the two species Chiropotes albinasus (monotypic) and Chiropotes satanas (three subspecies) [2], and Cacajao by Cacajao calvus (four subspecies) and Cacajao melanocephalus (two subspecies) [3]. The geographic distribution of this subfamily is restricted to the Amazon region. Recent morphological, karyotypic and molecular data pointed to a new species for Chiropotes, C. israelita, and indicated that the subspecies Chiropotes satanas utahicki should be accepted as a full species [4]. The majority of the Pitheciinae species are listed as endangered (http://www.cites.org webcite).It is accepted that the Pitheciinae represent a monophyletic clade [4-7]. Several studies using morphological [5-7], molecular [8,9] and cytogenetic [10] traits suggest that Chiropotes and Cacajao are sister taxa and place Pithecia most basal within this clade. It was further suggested that the Pi