Transgene correction of the Bst phenotype. (A) BAC clone RP23-10L10 (blue) contains Rpl24 and five other genes, and spans 181 kb (Ensembl mouse genome database, v. 12.3.1). (B) Founder Tg321 carries an intact RP23-10L10 transgene, which suppresses external Bst phenotypes in all doubly heterozygous offspring (compare mice 4514 and 4516 with 4515). Genotypes were determined using BAC end (red) and allele-specific Rpl24 PCRs. (C) Correction data summary. Four BAC transgenic founders were mated to C57BLKS Bst/+ mice. Tg321 and Tg326, which are intact, correct Bst phenotypes but Tg898 or Tg901, which lack Rpl24, do not. (D) Human RPL24 transgene (R26-huL24). The cDNA is ubiquitously expressed using the murine ROSA26 promoter.