The key difference between complementary and supplementary genes is that the complementary genes require the presence of each gene in expressing the trait, while only one gene out of the two supplementary genes requires the presence of the other gene when expressing the trait.
Genes interact with each other when producing a trait in an individual. These interactions are complex and need an in-depth analysis to understand how they work together, and how the presence of the genes affects the expression of traits. Complementary and Supplementary genes are two such kinds of genes that interact with each other when producing a trait. They show epistatic gene interactions meaning that the effect of one gene is dependent on the presence of the other gene.
CONTENTS
1. Overview and Key Difference
2. What are Complementary Genes
3. What are Supplementary Genes
4. Similarities Between Complementary and Supplementary Genes
5. Side by Side Comparison – Complementary vs Supplementary Genes in Tabular Form
6. Summary
What are Complementary Genes?
Complementary genes are two non-allelic genes that interact with each other to express a single character in combination. Their action is complementary. The presence of each other is necessary to express the character. If one is absent, other gene fails to produce the phenotype. Normally these genes locate themselves at different genetic loci. However, they work together to produce a particular trait.
What are Supplementary Genes?
Supplementary genes are also non-allelic genes that interact with each other when expressing a trait in an individual. However, unlike complementary genes that require the presence of both genes, one gene of the supplementary gene does not require the presence of the other gene to express. It expresses the trait on its own. Yet the second gene needs the presence of the first gene to express its trait.
Though the second gene is also dominant, it needs the help of the first gene to express. So, one dominant gene out of the two supplementary genes supports the expression of the second gene in this scenario.
What are the Similarities Between Complementary and Supplementary Genes?
- These genes show interactions when expression.
- Both gene types are non-allelic.
- Both genes of each category produce a single character.
What is the Difference Between Complementary and Supplementary Genes?
The complementary and supplementary genes are two types of genes that interact when producing a trait. They are non-allelic genes located in different genetic loci. The presence of both genes is necessary to express complementary genes. But one gene is dependent on the other gene for its expression in supplementary genes. One gene expresses without the presence of the second gene. The phenotypic ratios of complementary and supplementary genes are 9:7 and 9:3:4 respectively. The below infographic presents the side by side comparison of the difference between complementary and supplementary genes.
Summary – Complementary vs Supplementary Genes
The complementary and supplementary genes are two types of non-allelic genes that show gene interactions in expression. The action of complementary genes is complementary, where the presence of each gene is necessary to produce the trait. However, in supplementary genes, one dominant gene expresses without the presence of the other gene. But the second gene needs the presence of the first gene to express. This is the difference between complementary and supplementary genes.
Reference:
1.“COMPLEMENTARY GENES.” HUMAN BIOLOGY / SMALL INTESTINE – Pathwayz. Available here
2.“SUPPLEMENTARY GENES.” HUMAN BIOLOGY / SMALL INTESTINE – Pathwayz. Available here
Image Courtesy:
1.”163466″ by PublicDomainPictures (CC0) via pixabay