An Ordered Comparative Map of the Cattle and Human Genomes

TLDR

The study aims to create a comparative map that will serve as a foundation for understanding mammalian chromosome evolution and identifying agriculturally important genes. The authors built the map by combining radiation hybrid mapping, EST sequencing, database mining of unmapped cattle genes, and the COMPASS bioinformatics tool to target homologous regions. The map positioned 768 genes and 319 microsatellites, linked 638 cattle–human ortholog pairs, identified 105 conserved segments, 41 translocations, 54 internal rearrangements, and nearly all centromere repositioning, while COMPASS predicted cattle chromosome locations with 95% accuracy. GenBank accession numbers AW244888–AW244897, AW261132–AW261195, AW266849–AW267161, AW289175–AW289430, AW428566–AW428607, AW621146, and AW621147 contain the sequence data.

Abstract

A cattle–human whole-genome comparative map was constructed using parallel radiation hybrid (RH) mapping in conjunction with EST sequencing, database mining for unmapped cattle genes, and a predictive bioinformatics approach (COMPASS) for targeting specific homologous regions. A total of 768 genes were placed on the RH map in addition to 319 microsatellites used as anchor markers. Of these, 638 had human orthologs with mapping data, thus permitting construction of an ordered comparative map. The large number of ordered loci revealed ⋝ 105 conserved segments between the two genomes. The comparative map suggests that 41 translocation events, a minimum of 54 internal rearrangements, and repositioning of all but one centromere can account for the observed organizations of the cattle and human genomes. In addition, the COMPASS in silico mapping tool was shown to be 95% accurate in its ability to predict cattle chromosome location from random sequence data, demonstrating this tool to be valuable for efficient targeting of specific regions for detailed mapping. The comparative map generated will be a cornerstone for elucidating mammalian chromosome phylogeny and the identification of genes of agricultural importance.“Ought we, for instance, to begin by discussing each separate species—in virtue of some common element of their nature, and proceed from this as a basis for the consideration of them separately?” from Aristotle, On the Parts of Animals , 350 B.C.E. [The sequence data described in this paper have been submitted to the GenBank data library under accession nos. AW244888 - AW244897 , AW261132 - AW261195 , AW266849 - AW267161 , AW289175 - AW289430 , AW428566 - AW428607 , AW621146 , AW621147 .]