Hierarchical spatio-temporal population clustering. Factorial correspondence analyses based on genotype of O. niloticus samples at successive hierarchical spatial and temporal levels, depicting the best population clustering. For each population a star representation is used: every individual is linked with a line to the barycentre of its own population (labelled using sample code according to Table 1). At macro-geographic scale, we performed the projection of the 10 populations representing the overall biogeographic region studied (i.e. Ethiopian Rift Valley province, Nilotic, Sudano-Sahelian regions) on factorial planes F1 × F2 (a) and F1 × F3 (b), the projection of the Sudano-Sahelian region (i.e. West-African populations: Niger, Senegal and Volta basin populations) on factorial plane F1 × F2 (c), the projection of the Ethiopian Rift Valley province populations (i.e. Awash basin) on factorial plane F1 × F2(d). For the micro-geographic and temporal scales analysis, we performed the projection of the samples from the Volta basin including Kou, Kpandu and Nyinuto populations (temporal sample series are represented by stars and the area of each geographic population is represented by a 95% confidence ellipse), on factorial plane F1 × F2 (e). For each correspondence analysis, the percentage of variation represented by each factorial axis is given aside of its label.
Bezault et al. BMC Genetics 2011 12:102 doi:10.1186/1471-2156-12-102