Agroecology 3 min

Understanding the mechanism behind dominant and recessive gene expression

Report - Why are some genes dominant while others are recessive? After nearly a century of investigation, hypotheses and experiments, we finally understand the inner workings of this fundamental biological phenomenon. An article published in December 2014 in Science reveals the details. Read on to see how this scientific mystery was finally solved.

Published on 17 December 2014

illustration Understanding the mechanism behind dominant and recessive gene expression

The dominant and recessive relationship between alleles was one of the first observations made in the field of genetics by Gregor Mendel in the nineteenth century. Today, we know that various genetic traits, such as eye colour, blood types or certain genetic diseases, are either dominant or recessive.

Naturally, this fundamental biological phenomenon piqued the interest of scientists from the moment it was discovered. It even stirred up controversy in the 1930s among evolutionists.

Today, it stands as a rare example of a mechanism for which we can answer the age-old questions of why it exists and how it works.


The enormous progress made is the result of remarkable research, evolutionary hypotheses and experiments that draw from such fields as population genetics, physiology, bioinformatics, and molecular genetics.
This report tells the story of this discovery in three chapters.

See the complete folder:

Dominant and recessive gene expression, chapter One: evolutionary hypotheses
Fleur Brassica rapa-220
Dominant and recessive gene expression, chapter Two: the molecular mechanism for dominance
Fleur Arabidopsis thaliana-220
Dominant and recessive gene expression, chapter Three: back to evolution

Sylvain Billiard, Vincent Castric, Pascale Mollier Authors

Teri Jones-Villeneuve Translator


William Marande, Elisa PratNational Centre for Plant Genetic Resources (CNRGV).



Learn more


Three questions for a springing sprout: Mycophyto

Water and soil pollution, resistant pests, dwindling biodiversity… the adverse effects of pesticides on the environment are well-known. But what if we used natural synergies between plants and the micro-organisms that live in soil to ease through the agricultural transition? Mycophyto, a young start-up based in Sophia Antipolis, proposes effective biological alternatives for farming and landscaping. We sat down to talk with Justine Lipuma, co-founder of Mycophyto.

23 April 2019


Can organic farming manage without copper?

On 16 January 2018, INRAE presented the findings of a collective scientific expert report (ESCo) on the levers available to reduce the use of copper to protect organic crops. This expert report had been commissioned by the French Institute for Organic Farming (ITAB) and an INRAE federative research programme (the SMaCH metaprogramme). The approach of the ESCo involved an examination of the literature, and the results obtained could potentially be applied to other types of agriculture seeking to limit or eliminate the consumption of certain inputs.

16 January 2018


WeedElec, from "haute couture" to cutting-edge weeding

Launched at the beginning of 2018 under the aegis of 5 partners – including the EMMAH Joint Research Unit under the joint supervision of INRA and IRSTEA – the WeedElec project combines robots and drones for the detection and control of weeds using electric current. Claude Doussan is a researcher at INRAE Avignon, and presents its genesis and development.

17 December 2019