Analysis of the promoter region of the Xenopus borealis N-Cadherin gene

A Xenopus borealis genomic library was screened with the 5'-end of the Xenopus laevis N-Cadherin cDNA (DETRICK et a/., 1990). Four groups of clones were isolated that differed in restriction-enzyme digestion patterns. The sequencing of one of these clones, 3-9/4.8BS/pBS, has identified regions of DNA highly homologous to the X.laevis N-Cadherin gene. Accordingly, it is believed that the clone 3-9/4.8BS/pBS contains the 5'-end and promoter region of the X.boreal is N-Cadherin gene. A sequence analysis of this region has shown it to be GC-rich and has revealed consensus TATA-box, CCAAT-box and Spl binding sites. Other possible transcription-factor binding-sites have also been identified, as well as the first exon/intron boundary. A series of promoter-deletions were fused to the bacterial 3- galactosidase gene and micro-injected into X.laevis embryos. The 3- galactosidase staining patterns of whole embryos has visually shown that 1.3Kb of genomic DNA upstream of the translational start-site is sufficient to direct neural-specific transcription of this reporter gene.