title: Molecular phylogenetics of howler monkeys (Alouatta, Platyrrhini). A comparison with karyotypic data.
abstract: Molecular phylogenetic analyses of seven Brazilian Alouatta species, based on cytochrome b DNA sequence data were carried out. Parsimony and neighbor joining topologies grouped Alouatta belzebul and A. fusca as sister groups in one clade while another, well-supported clade contained A. seniculus as the most basal offshoot, followed by A. nigerrima as a sister lineage of A. macconnelli/A. stramineus. Estimates of inter-specific sequence divergence were generally low, and estimates of the time of divergence indicated that the main Alouatta lineages emerged during a short evolutionary interval. A comparison with karyotypic data confirmed the molecular topology showing a closer relationship between A. macconnelli and A. stramineus in respect to A. nigerrima. It also showed that the XX/XY sex chromosome system was maintained in several lineages while the X1X2Y/X1X1X2X2 system appeared independently at least three times during the radiation of howler monkeys. Moreover, the X1X2Y1Y2/X1X1X2X2 system might have appeared once or, alternatively, twice and independently.
authors.affiliation: Division of Genetics, Instituto Nacional de Câncer, Rio de Janeiro, Brazil.
authors.forename: C R
authors.initials: CR
authors.lastname: Bonvicino
authors.forename: B
authors.initials: B
authors.lastname: Lemos
authors.forename: H N
authors.initials: HN
authors.lastname: Seuánez
mesh_terms: D000508:Alouatta / Q000235:genetics*; D000818:Animals; D003573:Cytochrome b Group / Q000235:genetics*; D019143:Evolution, Molecular; D006239:Haplotypes / Q000235:genetics*; D007621:Karyotyping; D010802:Phylogeny; D016415:Sequence Alignment; D012730:Sex Chromosomes / Q000235:genetics*; D013997:Time Factors
chemical_list: D003573:Cytochrome b Group