Fig. 1. Generation of a conditional allele of Ift88. (A) Schematic representation of the targeting construct and the Ift88 genomic region, showing the location of the exons and the loxP sites. The deletion allele (Ift88ⁿ) was generated by leaky germline Cre activity in prx1cre females. The diagram is not drawn to scale. (B) Wild-type, floxed and null alleles (generated from the floxed allele) of Ift88 were distinguished by PCR using genomic DNA isolated from tail biopsies of mice. The approximate locations of the primers used for genotyping are indicated in A. (C) At E11.5, mice heterozygous for the (Ift88ⁿ) deleted allele and the previously described targeted Ift88^2-3ß-gal null allele of Ift88 (right) exhibited phenotypes characteristic of the congenic Ift88^2-3ß-gal null mice, including defects in the neural tube when compared with a wild-type littermate (left).