Isolation of CpG islands from large genomic clones.
AUTOR(ES)
Cross, S H
RESUMO
Positional cloning is a powerful method for the identification of genes. Using genetic and physical mapping methods the genomic region within which a particular gene is located can relatively easily be narrowed down to a comparatively small area contained within cosmid, PAC or BAC clones. It is then a matter of identifying genes within these clones. Here we describe the appli-cation of a technique, which has been successfully used for the bulk purification of CpG islands from whole genomes, to the isolation of CpG island sequences from such clones. As CpG islands overlap transcription units they can be used to isolate full-length cDNAs for associated genes, either by probing cDNA libraries or by searching databases. CpG islands are linked with approximately 60% of human genes and because their isolation is independent of the expression profile of these genes this approach would complement other expression-based methods of gene identification. By applying this technique to a cosmid clone known to contain the PAX6 gene we successfully isolated the CpG island for this gene along with other CpG island-like sequences. Closer examination revealed that an extensive genomic region around the 5'-end of PAX6 is unusual with regard to methylation and GC content. CpG island sequences were also successfully isolated from a PAC clone carrying the MBD1 gene. These included the complete CpG island containing the first exon and regulatory sequences from MBD1.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=148429Documentos Relacionados
- Preferential isolation of DNA fragments associated with CpG islands.
- CpG Islands of the Pig
- CpG islands of the X chromosome are gene associated.
- Number of CpG islands and genes in human and mouse.
- The isolation of CpG islands from human chromosomal regions 11q13 and Xp22 by segregation of partlymelted molecules.