Preliminary data on cytogenetics and cytotaxonomy of Cercopithecus albogoularis labiatus (Samango monkey)

Preliminary data on cytogenetics and cytotaxonomy of Cercopithecus albogoularis labiatus (Samango monkey) L. Sineo1, M. Roccella1, B. Picone1, R. Stanyon2, F. Genin3 and J. Masters 3 1Dipartimento di Biologia animale, Università di Palermo, Italia; 2Dipartimento di Biologia evoluzionistica, Università di Firenze, Italia; 3Department of Zoology and Entomology, University of Fort Hare, Alice, South Africa The systematic status and phylogenetic relationships of the C. mitis “species group” are contentious. The species group effectively includes very different species (C. nictitans, C. mitis, and C. albogularis) with wide, reciprocally remote distribution in Africa, and high regional variability (very high numbers of subspecies or local types). On the basis of morphology, four good species are recognisable: C. mitis, C. albogularis, C. nictitans, C. doggetti. On the contrary a recent molecular study recognised the C. mitis species grouping as a valid one, although chromosome studies had already suggested that the situation may be more complicated. Genomic reorganisation has great importance in the differentiation of species, as the organisation of genetic information in chromosomes, and in gametes, is a crucial factor in hybridisation. As the first step of the “Samango Project” (a collaboration between the Universities of Palermo and Fort Hare), formed to investigate the geographical differentiation of the populations of C. albogularis within the widely scattered and isolated fragments of South African mist belt forests, we performed a preliminary karyological analysis of the chromosomes of C.a. labiatus (CAL) individuals derived from the Eastern Cape and Mpumalanga. Giemsa-Trypsin banding was performed after tissue culture. CAL chromosomes were compared with C. mitis chromosomes. The diploid number in CAL is 72, as in C. mitis; the karyotypes are very similar but differ in a number of rearrangements. It is noticeable that karyotypes of CAL from the two South African localities differ by intrachromosomal rearrangements. The high level of chromosome polymorphism in these species its well-known. These preliminary data confirm that genomic organisation is polymorphic and probably regionally distinctive. Our results stimulate the application of more sophisticated molecular approaches as a proximate step, and the extension of the sampling to other populations of “Intsimango”, especially to the neighbouring C. a. erythrarchus.