Chromosome Mapping in Eukaryotes

Abstract

Construction of a series of descriptions indicating position and spacing of characteristics such as genes and other DNA sequence features along a chromosome is called chromosome mapping. The proposition of the chromosomal theory of inheritance by Sutton in 1903 led to the accumulation of evidence that genes are located on chromosomes. Morgan, through his Drosophila breeding experiments, determined location of white-eye gene locus on the X chromosome, and established chromosomes as carriers of genetic information. Also, it soon became obvious that the number of genes in any organism exceeded the number of chromosomes, suggesting location of several gene loci on an individual chromosome. Further studies on inheritances deviating from Mendelism, cell division (meiotic and mitotic) processes, and linear structure of eukaryotic chromosomes led to the concepts of genetic linkage, crossing over, and recombination.