Fig. 2: Species diversity and chromosomal evolution in aphids.
a On the left, the phylogenetic tree illustrates the relationships between the nine aphid species. Branches in the phylogeny are color-coded based on their respective average chromosomal rearrangement rates (supplementary Table 5). Rectangles on nodes represent the ancestral karyotype reconstruction, inferring a common ancestral karyotype (2n = 12) for five aphid species (S. heraclei, M. persicae, S. miscanthi, A. pisum, and N. formosana). Conservative blocks are coded according to the chromosomes from their common ancestor. Different colored numbers indicate the detected occurrences of chromosomal fissions (in red) and fusions (in blue). On the right, the genome syntenic plot is generated based on the gene order. Lines indicate the boundaries of syntenic gene blocks identified by MCScanX, with unconnected regions on the chromosomes possibly lacking syntenic gene blocks. Different chromosomes are color-coded with different links, and the X chromosome for each species is located on the far left and is depicted in gray. b The bar graph illustrates the number of species in each group within the Aphidomorpha15, with pentagrams indicating the average chromosome rearrangement rate for corresponding groups. Additionally, the boxplot depicts the chromosome counts in Macrosiphini, Aphidini, and other major subfamilies of aphids16 (median line, 25th–75th percentiles as boxes, Dots represent outliers). The dotted line indicates several major karyotypes of aphids15.
