Linkage Map Construction

Abstract

Genome mapping methods are generally divided into two categories: (1) genetic or linkage mapping and (2) physical mapping. Genetic mapping is based on the use of genetic techniques to construct maps showing the positions of genes and other sequence features on a genome, whereas physical maps are constructed by directly sequencing DNA molecules, and such physical map shows the positions of sequence features, including genes. There is yet another map in genome analysis, which is called as cytogenetic map. It is a genetic term used to describe the visual appearance of a chromosome (known as karyotype) when chromosomes are stained and examined under a microscope. Physical map identifies actual physical position of genes and other DNA elements on the chromosomes and facilitates positional cloning of agronomically important genes and analysing chromosomes and genome structure in detail (refer chapter x for detailed description). This chapter focuses on detailed description of genetic or linkage mapping besides briefly portraying other two types of mapping procedure.