3.1.2 Types of genetic interactions

3.1.2 Types of genetic interactions

The gene is a chemical determiner. The phenotypic trait results from the combined action of many genes and their products constantly interacting with the environment.
Phenotype=Genotype+Environment
  • The environment includes not only ecological factors such as temperature and light, but also internal factors such as hormones and enzymes.
  • The enzymes are proteins and the specific molecular organization of protein is determined by genes.
  • Biochemical studies indicated there is precursor and end products. A simplest biosynthetic pathway includes various steps, each step is catalyzed by a specific enzymatic protein and each enzymatic protein in its turn depends on a specific gene for its production(Fig.5.1). Figure needed

Fig. 5.1. Simple biosynthetic pathway.

Gene D produces enzyme D that act on IP3(Intermediate Product) that produces an end product. This gives the final phenotype.

  • If there is mutation in gene D, there is a break in the biosynthetic pathway. There will not change from IP3 to end product.
  • A different end product may be produced called as metabolic block. This is caused because of the mutation occurred in the particular gene.
  • Here two or more genes interact together to produce a particular phenotype.
Last modified: Tuesday, 22 November 2011, 10:22 AM