Karyotypic comparison among Cebuella pygmaea, Callithrix jacchus and C. emiliae (Callitrichidae, Primates) and its taxonomic implications

Abstract

The karyotype of Cebuella pygmaea (2n = 44) obtained by G-, C-banding, and NOR-staining is described. This species presents a heteromorphic C band in the intersticial region of the short arm of chromosome 2. The data obtained were compared with those previously described for the karyotypes of Callithrix jacchus and Callithrix emiliae. The three species differ in the amount and distribution of non-centromeric constitutive heterochromatin. The importance of the variation in constitutive heterochromatin for the phylogeny of the group is discussed. Comparison of the karyotypes in terms of G-banding patterns showed that C. pygmaea and C. emiliae differ from C. jacchus by a Robertsonian translocation and a paracentric inversion, whereas C. pygmaea and C. emiliae differ from each other by a reciprocal translocation between an acrocentric autosome and the short arm of the submetacentric chromosomes that distinguishes their karyotypes from that of C. jacchus. The possible evolutionary paths followed by the karyotypes of the three species are discussed.

Mitochondrial COII Gene Sequences Provide New Insights into the Phylogeny of Marmoset Species Groups (Callitrichidae, Primates)

“…3) is broadly similar to previous molecular phylogenies [5,6], the main difference being the exclusion of Cebuella as the sister group of Mico. This finding is incongruent with most other genetic evidence [20][21][22] and cranial morphology [23]. It seems likely that COII Sena/Vallinoto/Sampaio/Schneider/Ferrari/ Schneider may have been unable to resolve this phylogenetic question because of the temporal proximity of the separation events [5].…”

Investigation of marmoset hybrids <i>(Cebuella pygmaea</i> × <i>Callithrix jacchus)</i> and related Callitrichinae (Platyrrhini) by cross-species chromosome painting and comparative genomic hybridization

“…These regions correspond to chromosome segments that were not hybridized with any chromosome paint probes from other species (see Fig. 1A-D ) and that were previously identified to be C-band positive (Nagamachi et al, 1992;Alves et al, 1995). Our data indicate that these unbalanced regions are comprised of constitutive heterochromatin with sequence motives absent in human, L. lagothricha and S. oedipus, respectively.…”

Filogenia da tribo Callitrichini Thomas, 1903 (Primates, Platyrrhini, Callitrichinae), com base em caracteres morfológicos

“…Em se tratando das relações entre as espécies da tribo Callitrichini, a análise fenética realizada subsequentemente por Natori (1994) (Nagamachi et al 1992.…”

“…Barroso et al (1997) e Porter et al (1997) (Hershkovitz, 1977;Rosenberger, 1983), enquanto caracteres cariotípicos (e.g. Nagamachi et al 1992;Canavez et al 1996) aproximam C. pygmaea aos Callithrix amazônicos (= Mico, grupo de espécies -argentata‖). Porém, tais caracteres morfológicos e cariotípicos nunca foram utilizados numa análise filogenética comparativa dessas espécies a grupos-externos, com o objetivo de definir o estado plesiomórfico dessas características e verificar se há congruência entre os vários caracteres analisados em conjunto.…”

“…Cebuella pygmaea e Mico é considerado derivado em Callitrichinae, tendo se originado provavelmente a partir de uma translocação robertsoniana e por este motivo considero este um caráter homólogo nesses dois gêneros (Barros et al 1990;Nagamachi et al 1992) e convergente no distantemente relacionado…”