From chimera to homozygous null

From chimera to homozygous null


129 ES cells injected into C57BL/6 host blastocysts

Chimeric mouse ♂ x C57BL/6 ♀ = B6129F1 and/or C57BL/6

B6129F1 coat color agouti, 50% carry targeted alleles +/-

B6129F1 ♂ +/- x B6129F1 ♀ +/- = B6129F2

B6129F2 coat color mixed, 25% homozygous -/- founders

B6129F2 ♂ -/- x B6129F2 ♀ -/- = B6129F3

B6129F3 coat color mixed, 100% homozygous -/-

B6129F3 are used for initially characterizing targeted genes