In this article we will discuss about the concept and units of genes. Concept of Gene: Although the role of hereditary units (factors) in transfer of genetic characters over several generations in organisms was advocated by Gregor John Mendel, yet the mystery of the 'hereditary units' was un-ravelled during early 1900s. In 1909, W. Johanson coined the term 'gene' that [...]
In prokaryotes several mechanisms viz., transformation, conjugation and transduction have been described that mediate the formation of new recombinants. Transformation refers to transfer of relatively small segment of naked DNA from a donor cell (male) to the recipient (female) cell. Conjugation is the process of gene transfer between cells of opposite mating types that are in physical contact with each [...]
Some procedures applied for gene cloning in eukaryotes are described in this context: 1. Transformation of Filamentous Fungi 2. Gene Transfer through Ti-plasmid of Agrobacterium 3. Gene Transfer through Gene Gun 4. Gene Bank or Genomic Library. 1. Transformation of Filamentous Fungi: Like bacteria, transformation of filamentous fungi has also been demonstrated. Hinnen (1978) first described transformation of protoplasts of [...]