Gene mapping in biology for engineers.pptx

Gene mapping

1. Gene mapping

2. Gene mapping refers to the techniques used to identify a gene’s location and distance between genes. The distances between various sites inside a gene can also be described through gene mapping .

3. Types of Gene Mapping Genetic-linkage maps : Genetic-linkage maps show the location of each gene on a chromosome and their relative distances from one another. Initially, these maps were created by tracing the inheritance of several features, like eye colour and hair colour . Genetic mapping makes it possible to determine which gene is present on each chromosome and where it is located within that specific chromosome.

4. Physical Mapping: Physical maps always provide the actual DNA base pair distances between landmarks. It is one gene mapping approach that has a high degree of accuracy in determining the sequence of DNA base pairs. A physical map provides the nucleotide numbers and the precise physical distance between genetic markers. Radiation hybrid mapping, sequence mapping, and cytogenetic mapping are the techniques used to produce a physical map. Physical mapping assembles larger DNA sections using DNA markers and DNA fragments. Researchers can identify the locations of the  DNA  bases from the overlapping sections of the fragments.

5. Epistasis “Interaction between genes which determine a phenotype ” Epistasis is an interaction discussed at the phenotypic level of the organization. Genes at a particular epistatic interaction can exhibit independent assortment at the genotypic level. epistasis wherein the impact of a gene mutation depends on the absence or presence of mutations in one or more other genes referred to as modifier genes. Consequently, the epistatic mutations have various effects on their own than when it occurs together. Epistasis particularly is used to indicate that the effect of gene variant gets masked by other genes.