Isolation and characterisation of a diverse family of Arabidopsis two and three-fingered C₂H₂ zinc finger protein genes and cDNAs

In animal systems the C₂H₂ zinc finger protein (ZFP) gene family is the largest group of regulatory proteins and its members have a wide and important role in growth and development. It is likely that this family of ZFP transcription factors will also be important in plants. We have used a PCR approach employing highly degenerate oligonucleotide printers to isolate several Arabidopsis genomic and cDNA clones encoding potential ZFPs. In addition we have used the sequence information from these clones to identify two ESTs as members of this family. Five two-fingered and one three-fingered ZFPs have been identified. Outside of the zinc finger regions, there is considerable sequence diversity, including the sequence and length of the interfinger region; the expression pattern of each gene is different. This is the first report of the isolation of a three-fingered plant C₂H₂ ZFP gone and we discuss its possible evolutionary origin from two-fingered ZFP genes.