Cytogenetic maps of macrochromosomes and a list of genes mapped to microchromosomes in E. quadrivirgata . The chromosome locations of the genes are shown to the right of the rat snake chromosomes. The ideogram shows G-banded patterns. GC-rich (GC3 ≥ 50%) and GC-poor (GC3 < 50%) genes are shown in red and black, respectively. Homologous chicken chromosomes and their chromosome numbers (chicken Chr No.) are indicated to the left of the snake chromosomes. The inset table lists the genes mapped to snake microchromosomes and chromosome locations of their chicken orthologs are also given in the table. Chicken macrochromosomes (1–8 and Z) and microchromosomes (9–15, 17–22, 24–28) are distinguished by using different color, black and blue. ‘Un’ stands for unknown. The gene names are updated from our previous papers [38, 42], using the latest Ensembl build (v 68). The chromosome locations of the two genes, GNAI2 (BW999984) and P4HB (BW999985), were changed from our previous study  by reexamination of FISH. Chromosome locations of chicken orthologs are also updated according to databases.