RESUMO
Here we present, for the first time, the complete chromosome painting map of Saguinus midas, the red-handed tamarin. Chromosome banding and painting with human chromosome-specific probes were used to compare the karyotype of this species with those of four other Neotropical primates of the subfamily Callitrichinae: Leontopithecus rosalia, Callithrix geoffroyi, C. penicillata, and Mico argentatus. The chromosome painting map of S. midas was identical to that of L. rosalia and other previously studied tamarin species (genera Saguinus and Leontopithecus). The three marmoset species studied (genera Callithrix and Mico) differed in the painting pattern of four human probes (chromosomes 1, 2, 10, and 16). These paints identified the presence or absence of chromosome associations HSA 1/10 and 2/16 in these taxa. By integrating our data with those from the literature, we were able to propose an ancestral Callitrichinae karyotype. The genera Saguinus and Leontopithecus (tamarins) conserve the ancestral Callitrichinae karyotype, while Mico and Callithrix (marmosets) show more derived karyotypes due to chromosome translocations and fissions that occurred during the evolution of these taxa.
Assuntos
Callitrichinae/genética , Coloração Cromossômica/veterinária , Cromossomos de Mamíferos/genética , Saguinus/genética , Animais , Callimico/genética , Callithrix/genética , Linhagem Celular , Coloração Cromossômica/métodos , Cromossomos Humanos/genética , Sequência Conservada , Sondas de DNA/genética , Evolução Molecular , Humanos , Cariótipo , Leontopithecus/genética , Masculino , FilogeniaRESUMO
Sequences of a 0.9-kb DNA segment spanning intron 11 of the von Willebrand Factor gene (vWF) were determined for 21 individuals of 19 primate species. The results of maximum parsimony and maximum likelihood analyses of these vWF sequences are congruent with previous molecular findings from other nonlinked nuclear genomic loci which divide the platyrrhine superfamily Ceboidea into three monophyletic families: Cebidae, Atelidae, and Pitheciidae. The vWF results strongly support the taxon Callitrichinae as a monophyletic subfamily within Cebidae. The four extant callitrichine genera constitute tribe Callitrichini, and the basal branchings within this tribe first separate out Saguinus (tamarins), next Leontopithecus (lion tamarins), and last the sister genera Callimico (Goeldi's monkeys) and Callithrix (marmosets). Callithrix divides into three subclades, with pygmy marmosets (C. pygmaea) as sister of the C. argentata species group and with the C. jacchus species group as their sister. Fossil and DNA evidence place the emergence of the callitrichine clade in the basal cebid radiation at about 20 Ma (million years ago) and the three basal branchings in the callitrichin radiation at about 13 to 11 Ma. In turn, the branchings separating the three subclades of Callithrix are placed at about 5 to 4 Ma.
Assuntos
Callimico/genética , Callitrichinae/genética , Íntrons/genética , Filogenia , Fator de von Willebrand/genética , Animais , Sequência de Bases , Callimico/classificação , Callitrichinae/classificação , DNA/química , DNA/genética , Evolução Molecular , Feminino , Humanos , Masculino , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Fatores de TempoRESUMO
Primate pericentromeric regions recently have been shown to exhibit extraordinary evolutionary plasticity. In this paper we report an additional peculiar feature of these regions that we discovered while analyzing, by FISH, the evolutionary conservation of primate phylogenetic chromosome IX. If the position of the centromere is not taken into account, a relatively small number of rearrangements must be invoked to account for interspecific differences. Conversely, if the centromere is included, a paradox emerges: The position of the centromere seems to have undergone, in some species, an evolutionary history independent from the surrounding markers. A significant number of additional rearrangements must be proposed to reconcile the order of the markers with centromere position. Alternatively, the evolutionary emergence of neocentromeres can be postulated.
Assuntos
Centrômero , Primatas/genética , Animais , Callimico/genética , Callithrix/genética , Cebidae/genética , Mapeamento Cromossômico , Evolução Molecular , Gorilla gorilla/genética , Humanos , Pongo pygmaeus/genética , Saimiri/genéticaRESUMO
The New World monkeys are divided into two main groups, Callitrichidae and Cebidae. Callimico goeldii shares traits with both the Cebidae and the Callitrichidae. Recent morphological phyletic studies generally place Callimico as the most basal member of the Callitrichidae. In contrast, genetic studies (immunological, restriction fragment, and sequence data) have consistently placed Callimico somewhere within the Callitrichidae, not basal to this clade. A DNA sequence data set from the terminal 236 codons of the mitochondrial ND4 gene and the tRNA(His), tRNA(Ser), and tRNA(Leu) genes was generated to clarify the position of Callimico. The sequences of 887 base pairs were analyzed by maximum-parsimony, neighbor-joining, and maximum-likelihood methods. The results of these various methods are generally congruent and place Callimico within the Callitrichidae between the marmosets (Callithrix and Cebuella) and the tamarins (Saguinus and Leontopithecus). Combined analyses of all suitable nuclear and mitochondrial gene sequences confirm the position of Callimico between the marmosets and the tamarins. As available molecular evidence indicates that Callimico is more closely related to the marmosets than to the tamarins, a reconsideration of the morphological evidence in light of the consensus tree from DNA sequence analyses is warranted. The marmosets and tamarins share four morphological characters (loss of the third molar, loss of the hypocone, reduced body size, reproductive twinning). Dwarfism may have evolved repeatedly among the Callitrichidae. It is well-known that the loss of a character can occur many times independently. The reproduction of marmosets and tamarins is extremely specialized and it is difficult to imagine that this complex and unique twinning system evolved separately in marmosets and tamarins. However, it is possible that a secondary reversal to single offspring took place in Callimico.
Assuntos
Callimico/classificação , Callimico/genética , DNA Mitocondrial/genética , Evolução Molecular , Animais , Callimico/anatomia & histologia , Cebidae/anatomia & histologia , Cebidae/genética , Variação Genética , Modelos Genéticos , Dados de Sequência Molecular , NADH Desidrogenase/genética , Filogenia , Reação em Cadeia da Polimerase , RNA/genética , RNA Mitocondrial , RNA Ribossômico 16S/genética , RNA de Transferência de Histidina/genética , RNA de Transferência de Leucina/genética , RNA de Transferência de Serina/genética , Saguinus/anatomia & histologia , Saguinus/genética , Análise de Sequência de DNARESUMO
The systematic position of Callimico goeldi has been analyzed by comparison of its highly repeated DNA fragments with those of three species of Callithricidae and two species of Cebidae. Our data, in agreement with those obtained by other authors by means of cytogenetic and molecular biology techniques, are in favour of the classification of C. goeldi in the family Callithricidae.
