Organ Size Control Figure 1. Growth enhancemnt of E42 embryonic spleen implants in Factor VIII KO-SCID mice. (A) Upper panel: Macroscopic view at 3 months post transplant of E-42 spleen grafts implanted into NOD-SCID or Factor VIII KO SCID recipients. Lower panel: Representative H&E staining revealing similar morphological patterns in NOD-SCID (left) and in Factor VIII KO SCID (right) mice. (B) Pig mesenchymal components stained with anti-vimentin (V9) and proliferating pig cells stained with anti-ki67 within the implant growing in Factor VIII KO recipients are shown in brown. Asterisk points to mouse kidney not stained by these pig specific antibodies. (C) Average weight of E42 spleen grafts at 3 months post transplant in the two types of recipients, (n = 20). (D) Graft volume of the implants in the two recipient groups during the first 3 weeks post transplant and over a 5 months follow-up period. (E) Percentage of dividing ki67 positive cells per square mm in the growing implants. doi:10.1371/journal.pone.0008362.g001 PLoS ONE | www.plosone.org 3 December 2009 | Volume 4 | Issue 12 | e8362