Construction of a library enriched for human chromosome 11 and Xp YAC recombinants

YAC mapping by FISH using Alu-PCR-generated probes

Human genomic mapping has been greatly advanced by the independent development of three new methods: large DNA fragment cloning in yeast artificial chromosomes, amplification from complex DNAs of human specific segments by Alu-PCR, and high-resolution localization of complex DNA probes by fluorescent in situ hybridization. We describe here the combination of these three analytical tools for efficient and accurate localization of randomly screened or especially selected human YAC recombinants to chromosome 11. We map a YAC clone encompassing the pepsinogen A (PGA) locus to 11q13.1-11q13.3.

Distribution of Alu and L1 repeats in human YAC recombinants

Evidence is accumulating that the two major families of interspersed repeated human DNA sequences, Alu and L1, are not randomly distributed. However, only limited information is available on their relative long-range distribution. We have analyzed a set of randomly selected, human Chromosome (Chr) 11-specific YAC recombinants constituting a total length of about 2 Mbp for the local and global distribution of Alu and L1 repeats: the data show a strong asymmetry in the distribution of these two repeat classes and give weight, at the long-range molecular level, to previous studies indicating their partition in the human genome; they also suggest a strong tendency for L1 repeats to cluster, with a higher proportion of full-length elements than expected.