Intron conservation in the fragile X gene (FMR 1)

The intron probe STB12.3 was used to search for conservation of the intron sequence corresponding to the PstI fragment located approximately 450 bp downstream of the end of the first exon of the fragile X (FMR 1) gene. Standard techniques for DNA extraction, isolation, restriction enzyme digestion, blotting and probing were employed. The probe STB12.3 that hybridizes to an intron sequence in the human MR 1 gene is 1.2 bp long. Our results demonstrated that the STB12.3 sequence is conserved across at least two Kindgoms. Specifically, we have observed cross-hybridization between STB12.3 and sequences in Drosophila, Apis and Saccharomyces. Hybridization was not observed in Triticum. Most surprising was our observation of intron hybridization in Drosophila since Annemieke et al. (1991) did not find FMR 1 exon conservation in Drosophila. Intron sequence conservation had been previously reported but only between closely related (same Order) species.