Functional recovery and gene expression. (A) Whole blood clotting assay. Blood was withdrawn from the eye in a capillary tube. The clotting time was determined by visual observation of the clot formation. The results showed a significant drop in the blood clotting time in HAT mice after 5 months of transplantation compared with the HA mice. The number of mice tested (n) in each condition is mentioned in the figure. *P < .01. (B) Tail-clip challenge. The numbers of surviving and dead mice are shown after tail clip. In HAT mice, 80% were protected from death resulting from blood loss. The numbers of mice tested in each group are as follows: WT (9 mice), HA (13 mice), HAT-2 months (13 mice), HAT-5 months (17 mice), and HAT-12 months (14 mice). (C) The rationale for designing primers to amplify a sequence of the FVIII A3 domain. It is difficult to reverse transcribe across the neo sequence resulting from the presence of high G + C content in HA mice. (D) The RT-PCR analysis for the synthesis of the target amplicon. HAT1-3 mice show the synthesis of a 637-bp amplicon, the same as in WT mice. The same gene product was absent in both the knockout mice (HA1 and HA2).