Figure 2
Diving adaptations in the Chinese alligator genome. (A) Alignment of hemoglobin genes. Asterisk represents HCO3−-binding sites34. CA, AA, NC, and SC represent the Chinese alligator, American alligator, Nile crocodile, and Spectacled caiman. (B) Standard and HCO3−-binding O2 transportation pathways36. (C) Positively selected genes (PSGs) have been mapped to metabolic pathways by iPath37. (D) The pathways directly and indirectly participate in oxidative phosphorylation (according to map 01100, map 00190, and iPath). The color-shaded pathways correspond to those in C. (E) NH4HCO3 excretory pathways35 and maps 00460, 00480, and 00910. (F) Cardiac muscle contraction pathways (maps 05410 and 04260). The bicarbonate feature is highlighted in green, and the PSGs are shown in red. Bold lines depict the major pathways underwater, and the dotted lines indicate multiple linked steps in the pathway.
