A radiation hybrid map of mouse genes.

A comprehensive gene-based map of a genome is a powerful tool for genetic studies and is especially useful for the positional cloning and positional candidate approaches. The availability of gene maps for multiple organisms provides the foundation for detailed conserved-orthology maps showing the correspondence between conserved genomic segments. These maps make it possible to use cross-species information in gene hunts and shed light on the evolutionary forces that shape the genome. Here we report a radiation hybrid map of mouse genes, a combined project of the Whitehead Institute/Massachusetts Institute of Technology Center for Genome Research, the Medical Research Council UK Mouse Genome Centre, and the National Center for Biotechnology Information. The map contains 11,109 genes, screened against the T31 RH panel 1 and positioned relative to a reference map containing 2,280 mouse genetic markers2. It includes 3,658 genes homologous to the human genome sequence 3 and provides a framework for overlaying the human genome sequence to the mouse and for sequencing the mouse genome. We constructed the gene-based map of the mouse genome using the same basic strategy and methods as in our previous work mapping the human genome 4‐6 . We selected the genes from the mouse UniGene collection (http://www.ncbi.nlm.nih.gov/UniGene). Mouse UniGene build no. 86 includes 1,065,328 3′ESTs, 543,503 5′ ESTs and 18,786 mRNAs extracted from GenBank, representing longer and more accurate sequences. The alignment of these sequences generated 79,917 clusters, of which 43,213 contain at least two sequences. We selected for mapping clusters that have at least two sequences and either a polyadenylation signal or a poly(A) tail. A representative sequence was selected from each of approximately 30,000 clusters and registered with the RHalloc database at the European Bioinformatics Institute (http://corba.ebi.ac.uk:80/RHdb/RHalloc/). We generated STS markers for these genes and prescreened them against a panel of mouse and hamster DNA. We excluded approximately 38% of the assays because of the presence of a PCR product of similar size in hamster and mouse DNA.