| Functional |
"The KLKB1-encoded zymogen prekallikrein is activated by proteolytic cleavage to form the serine protease plasma kallikrein (PK). Similar to the knockout of F12, the knockout of KLKB1 in mice also granted protection from induced thrombosis while only slightly prolonging wound sealing (28)." |
10.1126/sciadv.aaw6671 |
| Timing of Loss |
"Our screen detected two blood coagulation-associated factors, F12 and KLKB1, that are specifically lost in cetaceans and no other analyzed mammal. Several shared inactivating mutations show that both genes were lost in the cetacean stem lineage (Fig. 1A and figs. S4 and S5)." |
10.1126/sciadv.aaw6671 |
| Phenotypic |
"While loss of KLKB1 protects from thrombosis by reducing the expression of F3 (coagulation or tissue factor III) (30), loss of F12 prevents activation on nitrogen microbubbles during diving. Because a vasoconstriction-induced reduction in blood vessel diameters and nitrogen microbubble formation increase the risk of thrombosis for frequent divers, the loss of both genes was likely beneficial for cetaceans." |
10.1126/sciadv.aaw6671 |