Chromosomal evolution in gazelles

The chromosomes of nine gazelle species and two other Antilopinae species (Antidorcas marsupialis and Antilope cervicapra) were prepared from fibroblast cultures. G- and C-band karyotypes were constructed, and when possible, autosomal arms were numbered according to the cattle standard karyotype. Diploid chromosome numbers ranged from 30 to 58. Based on band similarity, chromosome-arm homoeologies were extensive, whereas shared homoeologous biarmed chromosomes were rare. Therefore evolution in this genus could have occurred mainly by speciation following monobrachial homoeology of centric fusions. X to autosome translocations were common in the whole genus. Furthermore, chromosome Y was also involved in an autosome translocation in gazelles from the subgenus Nanger and in Gazella thomsoni and G. rufifrons. Based on these karyotypic data a phylogenetic tree is proposed. This phylogenetic reconstruction confirms most of the taxonomic relationships obtained by morphological analyses for this group of species. The main novelties are the proximity of G. rufifrons and G. thomsoni and the inclusion of Antilope cervicapra in the gazelle group.