Generation of conditional knockout alleles for PDGF-C

PDGF-C is a newly identified member of the platelet-derived growth factor (PDGF) family, which is involved in multiple cellular functions by signaling through PDGF receptor (PDGFR)-alphaalpha and alphabeta dimers. PDGF-C deficiency is perinatal lethal due to the formation of cleft palate. To further characterize the cellular function of PDGF-C during both embryonic and postnatal development, we have generated two conditional alleles of the Pdgf-c gene in which two loxP sites flank exon 5. Global Cre-mediated excision of the floxed exon 5 in these alleles resulted in a complete loss of PDGF-C expression and caused embryonic defects identical to those previously described for the PDGF-C null embryos. These conditional alleles will therefore be the important genetic tools for dissecting the spatial and temporal roles of PDGF-C during development and in adult tissues. Furthermore, from this work, we have also described a simple approach for creating mouse conditional alleles in an efficient manner.