Chromatin Nucleotide Content, Distribution, and Location In Ceboidea (Primates)

MUDRY, M.D.; BRESSA, M.J.; STEINBERG, E.R.

Foz do Iguaçu

Congreso; 2018 International Congress of Genetics; 2018

Sociedad Brasilera de Genética

One of the factors that characterize the genetic system of a species is the mode of chromosome/chromatin organization. Cytogenetic data published during last decades revealed that Neotropical Primates exhibit a heterogeneous karyology with rapid evolution as a distinctive feature of their genetic systems. To get a detailed characterization of chromatin organization and constitution in Ceboidea, we applied sequential fluorescent banding (DAPI/CMA3) in chromosome preparations of Alouatta caraya (ACA) (2n=52, X1X1X2X2/X1X2Y1Y2) and Cebus nigritus (CNI) (2n=54, XX/XY). In ACA, DAPI-/CMA3+ bands are observed either at one (e.g. pairs 1, 11-15, 18, 22) or both telomeric regions (e.g. pairs 3, 4, 8, 9), at pericentromeric region (e.g. pairs 1, 2, 4, 7, 15, 21, 23), and/or at interstitial position (e.g. pairs 1, 11-13, 16); meanwhile, pairs 5, 6 and 10 have no fluorescent bands. In CNI, DAPI-/CMA3+ bands are mainly located in one telomeric region (e.g. pairs 2, 3, 5-8, 11, 12, 14, 15-17, 21, 24), but are also detected in both telomeres (e.g. pairs 1, 4, 9, 10), at pericentromeric region (e.g. pairs 2, 20, 23, 24), and/or at interstitial position (e.g. pairs 6, 12, 13, 19). The X chromosomes in both species share the presence of centromeric and telomeric DAPI-/CMA3+ bands. These results evince a different chromosome organization in terms of the relative enrichment G+C base pairs and its location on the genomes of ACA and CNI. In Neotropical Primates, the combination of classical and molecular cytogenetic studies may be considered a powerful approach for elucidating the genome evolution processes.