FIG. 1.
Integration of human FMR1 (CGG)n arrays at the S. cerevisiae MAT locus. (a) Schematic representation of human FMR1 exon 1 and the positions of the primers 721 to 723 used in the amplification of various arrays. The (CGG)n portions of the array are shown as open boxes, and the AGG interspersions are shown as solid boxes. The arrays studied have structures of 10A9A9, 9A39, 9A48 (where A represents an AGG variant repeat), and (CGG)74 and are shown above a scale indicating their status in human fragile X families. The overall length of the triplet array (including the variant AGG repeat) is indicated. (b) Schematic representation of the integration of human FMR1 (CGG)n arrays, carried in the vector pJH257, into S. cerevisiae chromosome III at the MAT locus. Integration of FMR1 arrays, shown here in the (−) orientation, results in a direct duplication of the targeted MAT locus. The positions of ARS314 and ARS310, relevant restriction sites, and the orientation with respect to the centromere and telomere are also shown.