Heterochromatin and cytogenetic polymorphisms in Cebus apella (Cebidae, Platyrrhini)

Abstract

Cytogenetic studies have been carried out in 39 specimens of C. apella of different origins. Three different morphologies, one affecting the long arm of chromosome 4 and two affecting pair 17, have been detected. In each case, they can be related by paracentric inversions. Heterochromatin polymorphisms affecting terminal or interstitial C + regions have also been observed. The length of the terminal heterochromatic region in the long arms of chromosome 11 is variable in C . apella sp., in C . a. paraguayanus and absent in the C . a. nigritus specimens studied. Interstitial C + bands can be observed in the long arms of the biarmed chromosomes 4 and 6, and in the long arms of the acrocentric pairs 12, 13, 17, 18, 19, 20, and 21.Interstitial C + bands in the long arms of chromosomes 4,12, 17, and 19are present in all animals studied, although their size is variable, especially in the case of chromosomes 17 and 19. o 1995 Wiley-Liss, Inc.

New polymorphisms in a Cebus (Platyrrhini, Primates) species. The case of Cebus nigrivittatus

“…the constitutive heterochromatin regions, as has previously been described in the species of the same genus: C. apella (Seuá nez et al, 1986;Freitas and Seuá nez, 1982;Matayoshi et al, 1987;Ponsà et al, 1995;García et al, 2003) and C. capucinus (Dutrillaux et al, 1978;Garcia et al, 1983;Carlà and Stanyon, 1992). In C. apella, previous reports have detected size variation of non-centromeric heterochromatin regions in chromosomes 4, 6, 11, 12, 17, 18 and 19 (Matayoshi et al, 1987;Ponsà et al, 1995). In the case of the six specimens of C. nigrivittatus analysed, polymorphisms affecting the size of heterochromatin regions have been observed in the 1p, 11 and 19 C+ bands (Figure 2b).…”

“…All interstitial and terminal C+ bands detected are G negative, except pair 16 (Figure 2a), whereas all centromeric C+ bands are G positive, like other species of Cebus (Ponsà et al, 1995). Terminal C+ bands in the p arm in the longest chromosomes of the karyotype have also been observed in C. capucinus homologous 1p, 2p and 3p chromosomes.…”

“…Based on G-banding comparisons and chromosome painting results (García et al, 2002), some differences have been observed in relation to the presence of C+ bands between C. apella and C. nigrivittatus karyotypes. In the C. apella karyotype, C+ bands were not observed in 1p, 2p, 3p, 8, 16 and 24 chromosomes, whereas the C+ band described in C. apella chromosome 6 (Matayoshi et al, 1987;Ponsà et al, 1995) was not detected in the homologous C. nigrivittatus chromosome. The presence of the terminal C+ band in chromosomes 1, 2 and 3 has been also detected in C. capucinus (Garcia et al, 1983).…”

“…Metaphases were sequentially stained according to Seabright (1971) for Gbands, and to Sumner (1972) for C-bands. Chromosomes were arranged according to García et al (2002) taking the standardised karyotype of C. apella (Matayoshi et al, 1986;Ponsà et al, 1995) as a reference.…”

“…In this context, some primate species have been widely analysed, but in other published studies are scarce, as is the case of Cebus genus (Family Cebidae, Primates). In this group, C. apella (CAP) and C. capucinus (CCA) have been widely studied (Dutrillaux et al, 1978;Garcia et al, 1983;Matayoshi et al, 1987;Mudry, 1990;Ponsà et al, 1995;García et al, 2000García et al, , 2003, whereas no data on heterochromatin polymorphisms have been published for C. nigrivittatus or Cebus albifrons.…”