DNA and rDNA Explained

DNA and rDNA Explained

DNA AND rDNA Explained

Every living organism has its method of reproducing or replicating itself. These methods vary among different species. Some organisms reproduce at the cellular level, others reproduce in a more complex way.

DNA and rDNA are related scientifically and are both referred to in terms of genetic codes and information needed for reproduction and cell division. However, they vary in some ways. We’ll take a look at what both terms entail and how they function.

What Is DNA?

Deoxyribonucleic acid(DNA) is a complex organic molecular structure that contains genetic codes and information contained in a cell and is necessary for the reproduction, development, and function of an organism. They are present in eukaryotic cells( cells with a defined nucleus), prokaryotic cells( cells without a defined nucleus), and viruses as well.

Discovery Of DNA

The DNA molecule was first discovered by a Swiss researcher, Johann Friedrich Meischer while trying to study white blood cells in the year 1869. However, credit is also given to James D. Watson and Francis H.C. Crick, notable for discovering the double helix structure of the DNA in 1953.


DNA is a molecule that is two-stranded and contains codes or instructions responsible for the transmission of traits from parents to offspring. However, these instructions are being synthesized into proteins, that in turn determine the traits that are being passed to offspring during reproduction. Threadlike structures made up protein and DNA are known as Chromosomes.

DNA Composition, Structure, And Storage

A DNA strand is composed of long chain molecules known as nucleotides. Each monomer molecule however consists of 3 components: a phosphate group, a nitrogenous base, and a five carbon, deoxyribose sugar.

The structure of a DNA can also be denoted as a “twisted ladder”. It is however known to have the double helix structure. The building blocks or information stored as a code in the DNA are composed of 4 chemical bases: adenine (A), thymine (T), guanine (G), and cytosine (C)

These nitrogenous bases form pairs that constitute the double helix structure of DNA. The pattern of a pairing of these bases is as follows: A to T and C to G. Moreover, one important part of the structure of the DNA is the deoxyribose sugar, which is also known as the backbone of the structure of a DNA molecule.

What Is rDNA?

The term rDNA can be used in two different sense:

  • Recombinant DNA
  • Ribosomal DNA

Recombinant DNA

Recombinant DNA refers to the genetic combination of two different fragments of DNA, from different species, to form a new strand of DNA. This is also known as Chimera. They are also composed of 3 different methods: transformation, non-bacterial transformation, and phage introduction.

How It Works And Its Function

Recombinant DNA works when there’s a visible amount of protein expression from the host cell. However, this visible amount of protein expression must be from the host or rDNA will not be synthesized. The proteins obtained from the expression of rDNA in a living cell are known as recombinant proteins. Also, to obtain the expression of foreign proteins, specialized expression vectors.

The function and application of recombinant DNA have proven to be very useful in various sectors like healthcare, agriculture, biotechnology, and research, among others. Some specific areas of application include:

  • For producing clotting factors for cases like hemophilia
  • For the production of vaccines in cases of Hepatitis B
  • Production of insect and heat resistance crops
  • Production of human growth hormones and insulin.
  • For pharmaceuticals
  • For the prevention and production of cures for sickle cell diseases.

Ribosomal DNA

Ribosomal DNA (rDNA) is a type of DNA that is found in the ribosomes of cells. Ribosomes are responsible for protein synthesis, and rDNA plays an important role in this process. The sequence of rDNA is used to create proteins that are essential for cell function. In addition, rDNA is involved in the regulation of gene expression. Because of its important role in cell function, rDNA is a target for studies that aim to understand how genes are expressed. Additionally, rDNA has been used as a tool for identifying and classifying different species of organisms. Therefore, ribosomal DNA is a vital component of cells that plays an essential role in both protein synthesis and gene expression.

rDNA Technology

In the past, rDNA technology was thought to be just an imaginary conception that could be deployed to modify certain traits and characteristics in living bodies by controlling the expression of target genes. Thankfully, in recent times, as a result of the input by researchers, rDNA technology has demonstrated significant advancement in human life and science at large.

Recombinant DNA technology is defined as a process of merging two different molecules of DNA and inserting them into a new organism.

Another aspect of recombinant DNA technology is “DNA Cloning”-which refers to a technique used in creating copies of DNA molecules, genes or organisms and induce their reduplication in host organisms. The single partners of a clone are similar genetically because cell replication generates similar daughter cells every time.

The usage of cloning has been broadened to recombinant DNA (rDNA) technology, which has given scientists the means to produce several copies of a single fragment of DNA. The importance of recombinant DNA cannot be over-emphasized, as it has been proven to be responsible for the increase in the genetic diversity of eukaryotes. Another useful importance of recombinant DNA technology is visible in the production of insulin. Insulin is obtained from the human insulin gene that is introduced into a plasmid and then to a bacterial cell where the protein insulin is further produced.


For every form of life, there’s a means of replication and reproduction to ensure the continuity of such species in question. The stages of development and reproduction could take place at the cellular level and that is where the concept of DNA and rDNA comes in.

More so, research and technology are committed to ensuring that the application of recombinant DNA technology proves to be useful in sectors like healthcare, agriculture, and biotechnology, among others.