Cytogenetic study of five species of Cercopithecus.

The G- and C-banded karyotypes of five species of Cercopithecus are reported. The chromosome numbers are: for C. ascanius katangae 2 n = 66 (XX); for C. petaurista petaurista 2 n = 66 (XY); for C. mona mona 2 n = 68 (XX); for C. pogonias grayi 2 n = 72 (XY) and for C. hamlyni 2 n = 64 (XY). We always found three types of chromosome: metacentric, sub-metacentric and acrocentric. The 'marker chromosomes' typical of the Cercopithecidae are of the last type. The karyotype of C. pogonias grayi shows a characteristic pair of acrocentric autosomes which is again found in the hybrid karyotypes.