Generation of Tcf7l2 null mice using zinc finger nuclease technology. (A) Mouse Tcf7l2 gene exons 9, 10, and 11 are shown. The 6-bp of sequence targeted in exon 11 by zinc finger nucleases (ZFNs) is shown below in red along with flanking sequences. A horizontal line marks a codon. Deletions from the three knockout lines generated are shown below the wild-type sequence. (B) Images of Tcf7l2+/+ and Tcf7l2−/− mice that show a lack of milk within the stomach (white arrows). (C) Neonatal body weights for wild-type (+/+, n = 37), heterozygous null (+/−, n = 81), and homozygous null (−/−, n = 25) mice. (D) Scatter plots of neonatal blood glucose measurements for wild-type (+/+, n = 36), heterozygous null (+/−, n = 83), and homozygous null (−/−, n = 19) mice. Red bars mark the mean blood glucose level. (E) Plasma insulin values for wild-type (+/+, n = 9), heterozygous null (+/−, n = 24), and homozygous null (−/−, n = 6) animals. Red bars mark the mean insulin level.
