Codominance in Dictionary

In order to fully understand the meaning of the term codominance, it is necessary, first of all, to discover its etymological origin. In this case, we can state that it is a word of Latin origin that is the result of the sum of four very well delimited parts:
-The prefix “with”, which can be translated as “together” or “all”.
-The verb “dominate”, which is synonymous with “have under their power.”
-The particle “-nt-“, which is used to indicate “agent”.
-The suffix “-ia”, which is used to indicate “quality”.

Genotype is called the genetic data that, according to its allelic composition, a certain organism has in its deoxyribonucleic acid (DNA). Allelic, for its part, comes from an allele: each alternative form that the same gene can adopt according to its sequence, which are located in the same place on the homologous chromosomes.

According to DigoPaul, codominance is a situation that occurs when two different alleles are found in the genotype and both are expressed. In this state, the expression of both alleles results in a phenotype (the manifestation of the genotype that varies according to the environment) with characteristics of both.

Therefore, it can be established that codominance is a type of genetic inheritance that has the characteristic that dominant characteristics are inherited from both parents.

A clear example to understand codominance is the one that establishes that an individual, in relation to their blood group, who has an A allele and a B allele will have an AB blood type. Of course, because the aforementioned alleles are codominant with each other.

With codominance, therefore, the expression of a gene in a heterozygous organism is equivalent to that of its peer. Heterozygotes, in this way, present the two alleles of the same gene in relation to a certain trait. In incomplete dominance, on the other hand, the two alleles are also expressed, but in a genotype that presents intermediate characteristics.

It can be said that, in heterozygotes, there are two alleles that are expressed but do not join. Suppose that a codominance cross of two species of horse is made: one black and one brown. The result of the cross will be a horse with black and brown spots since the two codominant alleles are expressed simultaneously.

Similarly, a yellow flower A and a blue flower B, in a codominance interbreeding, will allow the creation of an AB flower whose color will be yellow with blue spots: both codominant characters appear expressed.

In addition to all the above, it is important to know that it is considered that codominance as such was a discovery, a theory, established by the biologist and writer Teresa Audesirk (1950). Apparently, he raised it in a forceful way in his work entitled “Life on Earth”, thus taking a great step in the field of biology that has made it possible to advance a lot in it in recent years. However, it is considered that it has not received the recognition it deserved.