IMED2004 Study Guide - Final Guide: Abo Blood Group System, Gene Mapping, Blood Type
Document Summary
The process of determining the locus for a particular biological trait. Determination of the relative positions of genes on a dna molecule (chromosome or plasmid) And of the distance, in linkage units or physical units, between them. = determining the relative positions of genes on a chromosome and the distance between them. Efforts in mapping human genes hampered by inability to perform desired crosses and small number of progeny. Restricted to analysis of human pedigrees, often incomplete, limited information. As progeny numbers are small, data from several families are often combined. One of first documented demonstrations of linkage, between locus for nail-patella syndrome and abo blood type. Nail-patella syndrome is autosomal dominant (nn), abnormal fingernails, absent kneecaps. Abo blood types autosomal locus with multiple alleles. We can use recombination to assess genetic linkage, which can detect position and order of loci on chromosome. Humans produce small number of offspring so it makes linkage difficult to make and pedigree incomplete.
