Major Features of the Gene

Abstract

Over the years, the gene has received numerous definitions, many of which became widely accepted. It has long been known as the unit of inheritance, or the factor that results in a given hereditary trait, definitions that continue in use today; it was also considered a point, or locus, on a chromosome that serves in the foregoing capacity. Later, as the molecular aspects of cell function began to unfold, a better understanding of the nature of the gene was gained, and the concept of “one gene, one protein” came into existence. Then, when proteins were perceived as being constructed of several subunits, each the product of a separate locus, that view became modified to “one gene, one polypeptide.” All these ideas are both sound and unsound; even the most recent, which defines a gene as a sequence in the nucleic acid of the genome, contains an element of weakness, which will become apparent as the discussion of gene structure proceeds immediately below.