Generation of a high-density rat EST map

We have developed a high-density EST map of the rat, consisting of >11,000 ESTs. These ESTs were placed on a radiation hybrid framework map of genetic markers spanning all 20 rat autosomes, plus the X chromosome. The framewor k maps have a total size of similar to 12,400 cR, giving an average corresp ondence of 240 kb/cR. The frameworks are all LOD 3 chromosomal maps consist ing of 775 radiation-hybrid-mapped genetic markers and ESTs. To date, we ha ve generated radiation-hybrid-mapping data for >14,000 novel ESTs identifie d by our Rat Gene Discovery and Mapping Project (http://ratEST.uiowa.edu), from which we have placed >11,000 on our framework maps. To minimize mappin g errors, ESTs were mapped in duplicate and consensus RH vectors produced f or use in the placement procedure. This EST map was then used to construct high-density comparative maps between rat and human and rat and mouse. Thes e maps will be a useful resource for positional cloning of genes for rat mo dels of human diseases and in the creation and verification of a tiling set of map order for the upcoming rat-genome sequencing.