Analysis of constitutive heterochromatin of Aotus (Cebidae, Primates) by restriction enzyme and fluorochrome bands.

The current classification of genus Aotus includes nine species, four of which occur above the Amazon River and five below it. The position of several of these taxa as a valid species has been questioned. Recently, we described the chromosomal constitution of a population in the state of Rondonia, Brazil, whose karyotype typically presented a considerable accumulation of constitutive heterochromatin. To best characterize these heterochromatins, in this work we subjected the metaphases of these animals to banding using AluI, HaeIII, HinfI, RsaI, DdeI, MboI and MspI restriction enzymes and CMA3 and DAPI fluorochromes. The banded metaphases were also submitted to sequential C-banding. RsaI, DdeI and MboI enzymes showed, in all chromosomes, a banding pattern of C type, similar to that obtained using barium hydroxide. This banding was also seen with AluI, HinfI and MspI, but with reduction or elimination of the C-bands in the chromosome pairs 1, 3-7 and 9. MspI also reduced the C-band of pairs 11, 16-21 and 23. HaeIII induced intermediate bands between G and C. Considering the data of the different bands produced, it was possible to characterize at least three distinct types of constitutive heterochromatin in Aotus from Rondonia: (a) centromeric bands, (b) bands of the heterochromatic short arms and (c) interstitial bands.