Over the past 10 years great progress has been made in the development of efficient techniques for both gene isolation and mapping. The identifica tion and isolation of transcribed sequences from large chromosomal regions are central to the human genome mapping project. Techniques for isolating novel cDNAs have applications both in the overall construction and integra tion of long-range physical and transcription maps and in the identification of disease genes. A number of different techniques for the isolation of cDNAs from mam malian genomes have been developed, including screening "zoo" blots, the use of large genomic clones (YACs or cosmids) for hybridization against cDNA libraries, and CpG island mapping. More recently two highly efficient tech niques have been introduced: exon trapping, based on the presence of exon splice sites, and direct selection, based on the enrichment of selected cDNAs using immobilized YACs or cosmids. Leading researchers in the field have contributed chapters detailing the practical procedures for these and other widely used methods. The most rapid progress presently being made in the field of gene isolation concerns the partial sequencing of cDNA clones from one or both ends to produce expressed sequence tags (ESTs). Indeed, by Octo ber 1995, the EST division of Genbank (dbEST) contained a total of approxi mately 270,000 human EST sequences accounting for almost half the number of sequence entries in Genbank.

Zusammenfassung
This text is designed for those wishing to learn the techniques applied by experts in gene mapping. It includes: the localization of genes by FISH and linkage analysis; gene isolation by YAC hybridization; direct selection; and exon trapping and differential display.

Inhalt
Gene Mapping Goes from FISH to Surfing the Net.- Linkage Analysis of Genetic Disorders.- Gene Ordering and Localization by Linkage Analysis.- Gene Mapping Using Somatic Cell Hybrids.- Gene Mapping by FISH.- Probe Ordering and Distancing by FISH.- Physical Mapping by Pulsed-Field Gel Electrophoresis.- Construction and Use of YAC Contigs in Disease Regions.- Construction and Use of Cosmid Contigs.- Use of Dinucleotide Polymorphism Analyses in Physical Mapping.- Mapping Expressed Sequence Tags (ESTs) by Multiplexing PCR Reactions from Hybrid Cell Panels and Detecting Fluorescently Labeled Products.- Gene Isolation by Exon Trapping.- Isolation of Coding Sequences from Genomic Regions Using Direct Selection.- Isolation of cDNAs Using the YAC Hybridization Screen Method.- Detection and Isolation of Differentially Expressed Genes by Differential Display.- Chemical Crosslinking Subtraction (CCLS).- Gene Mapping and Isolation.- Software for Genetic Linkage Analysis.- Exon Detection by Similarity Searches.