Short Notes on Essential Properties of Gene

The below mentioned article provides a short note on the Essential Properties of Gene.

There are, however, certain essential proper­ties of genes. As the genes control all characters transmitted from generation to generation, the gene must have the stability or permanency in the cell, principally in the nucleus. It implies that, it must be an essential component of all cells of the organism.

It cannot be a transitory or ephemeral substance appearing at certain stage of an organism and disappearing in others. The permanence and universality are essential requi­sites of the genetic material.

i. The genes are present in each and every cell of an organism ranging from unicellular zygote of the eukaryote to the adult organism. In unicellular organisms too, it is ubiquitous. The genes can replicate, the basic property of a living system the autocatalysis.

ii. The basic tenet is, the gene controls all the characters of an organism. The control of all the characters – direct or indirect, is otherwise termed as hetero-catalysis. As such, genes must have the property of hetero-catalysis as well.

iii. In the evolution of life and its gradual progression of diversification through geological ages, it is well established through researches of different workers that new characters originate in the process of evolution. The origin of new characters can be attributed to natural variation or mutation and recombination or shuffling of existing characters.

As the genetic material or genes are responsible for all characters, the property of mutation and recombination is also inherent in the genetic material.

Thus the genes – the permanent material basis of heredity have the property of:

(a) Auto­catalysis, i.e., replication producing its own replica,

(b) Hetero-catalysis, i.e., catalyzing other reactions and

(c) Mutation and recombination for the production of variations of characters.

The DMA has been demonstrated to be the genetic material on the basis of evidences of pneumococcal transformation and bacterio­phage multiplication. However, in order to establish DNA as the gene substance, it is essen­tial to show that, it has the properties of auto­catalysis, hetero-catalysis and mutation – the inherent characters of gene.

Autocatalysis:

Gene can replicate, i.e., DNA undergoes replication in each cell cycle at ‘S’ phase to make the amount of DNA double prior to cell division.

Hetero-catalysis:

Knowledge of gene- enzyme relationship stems largely from research with a number of different microorganisms; and many ideas of this relationship were derived from experiments with Neurospora initiated by Beadle and Tatum. DNA produces m-RNA by transcription; m-RNA undergoes translation into protein (enzyme).

Mutation:

Another essential property of the gene is its capacity to undergo alteration or mutation which is responsible to bring about diversity in evolution. DNA being the gene sub­stance, has the capacity for mutation.