Difference Between Genocopy and Phenocopy

The key difference between genocopy and phenocopy is that in genocopies, phenotypes show similarity and the genotype alters, while in phenocopy, phenotypes vary and the genotype remains unchanged.

The disparity between genocopy and phenocopy is involved in explaining the rare occurrences of genetics. The two concepts demonstrate how traditional genetics or Mendelian genetics can vary based on the exceptions in nature. Genocopy refers to the phenomenon of giving a similar phenotype despite having a different genotype. In contrast, phenocopy refers to the phenomenon of having varying phenotypes despite the genotype remaining unchanged.

CONTENTS

1. Overview and Key Difference
2. What is Genocopy 
3. What is Phenocopy
4. Similarity Between Genocopy and Phenocopy
5. Side by Side Comparison – Genocopy vs Phenocopy Theory in Tabular Form
6. Summary

What is Genocopy?

Genocopy is a phenomenon that occurs due to a phenotypic copy of a genetic character that is a resultant of a different genotype. The inception of the term Genocopy began with Dr H. Nachstheim. In this concept, the phenotype resulting from both genotypes are similar; therefore, they are genocopies. However, the locus of the individual genotypes may vary. These are also termed as genetic mimics.

Genocopies can be inherited or can be due to a mutation caused by environmental changes. The identification of genocopies is mainly through carrying out a test cross where the individual genotypes segregate during crossing. The effect of a genocopy can vary from no effect to serious health disorders and complications.

Mitochondrial diseases are mostly due to mutations caused by genocopies. Thus, they may lead to the expression of certain proteins that cause mitochondrial diseases. DiGeorge syndrome is yet another genetic disease caused by a genocopy.

What is Phenocopy?

A phenocopy is a difference in phenotypes that is pre-determined by a genotype. The emergence of this concept was followed by the observations of Richard Goldschmidt. The key aspect regarding a phenocopy is the significant role played by varying environmental conditions. This type of change is not heritable. Moreover, phenocopy is not a result of a mutation, unlike the concept of genocopy. Therefore, the severity of the effect is less in terms of a phenocopy.

There are many natural examples of this concept of phenocopy. The butterflies belonging to the genus Vanessa can change its phenotype in response to the external temperature. Furthermore, the larvae of Drosophila show varying phenotypes in the form of phenocopies in response to temperature, radiation, shock and chemical compounds. Himalayan rabbits also show phenocopies in response to temperature.

What is the Similarity Between Genocopy and Phenocopy?

• Both show active responses to environmental changes

What is the Difference Between Genocopy and Phenocopy?

The two terms Genocopy and phenocopy mainly differentiate between the variation of their genotype and the phenotype. In genocopies, phenotypes show similarity and the genotype alters, while in phenocopy, phenotypes vary and the genotype remains unchanged. So, this is the key difference between genocopy and phenocopy. Furthermore, the manner in which the genocopy and phenocopy emerge also varies.

The below infographic tabulates more information on the difference between genocopy and phenocopy.

Summary – Genocopy vs Phenocopy

Genocopy and phenocopy show a distinction following some rare occurrences in nature. Genocopy refers to mutations in genotypes resulting in a similar phenotype. In contrast, phenocopy refers to the change in phenotypes with a similar genotype. While genocopy can take place either due to mutations or environmental changes, phenocopy takes place mainly due to environmental changes. The heritability of the two phenomena also changes. Thus, this is the summary of the difference between genocopy and phenocopy.

Reference:

1. Zori, R T, and C A Williams. “Phenocopy versus Genocopy.” American Journal of Medical Genetics, U.S. National Library of Medicine, 1 Aug. 1991, Available here.

Image Courtesy:

1. “DiGeorge syndrome1” By Prof Victor Grech –  (CC BY-SA 3.0) via Commons Wikimedia

2. “Marzahn Gaerten der Welt 08-2015 img12 Red Admiral” By A.Savin (Wikimedia Commons · WikiPhotoSpace) – Own work (CC BY-SA 3.0) via Commons Wikimedia