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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #305448

Title: Genetic and physical map correlation

item O`Rourke, Jamie

Submitted to: Popular Publication
Publication Type: Popular Publication
Publication Acceptance Date: 8/20/2014
Publication Date: 11/14/2014
Citation: O'Rourke, J.A. 2014. Genetic and physical map correlation. Popular Publication. doi: 10.1002/9780470015902.a0000819.pub3.

Interpretive Summary: Genetic and physical maps are important genetic tools. The maps illustrate the organization of DNA sequences along a chromosome. Both types of maps can be built using the same types of molecular markers (short pieces of unique DNA). While genetic maps are constructed by comparing recombination frequencies between marker pairs, physical maps use markers to identify overlapping sequences between larger pieces of DNA. These maps can be used to examine the evolutionary history of genomic sequence between distantly related species. Additionally, they are important foundations which whole genome sequencing projects can rely upon to ensure sequences are correctly assembled.

Technical Abstract: Genetic and physical maps illustrate the arrangement of genes and DNA markers on a chromosome. The relative distances between positions on a genetic map are calculated using recombination frequencies while a physical map is based on the actual number of nucleotide pairs between loci. These maps are a key resource for understanding genome organization. They are the basis for map-based cloning and marker assisted selection; serving as a bridge between breeding and sequencing research. Comparing marker position and order may provide interesting insight into the evolutionary history of even distantly related species. Physical and genetic maps can unravel the complexities of large duplicated genomes intractable to sequencing efforts; while in species more amenable to genetic studies high resolution maps provide the scaffold upon which whole genome sequences are assembled. A complete genome sequence is a physical map at its highest resolution.