Microscopy image of an Arabidopsis root tip. Legend: Green marker in the cytoplasm of specific root tip cells (quiescent center and columella), cell wall staining in magenta. ©Bradamante/Mittelsten Scheid/GMI.
Gregor Mendel, the “father of genetics,” is often mentioned together with Charles Darwin or Louis Pasteur, the greats of science. But how do we benefit from Mendel’s discoveries in our everyday lives today?
MENDEL IN EVERYDAY LIFE: LOOKING AT THE INNER CHARACTERISTICS
At the very beginning, people simply selected plants that looked better than others to breed for the following year,” says Carl-Stephan Schäfer of the German Plant Breeders’ Association. “It was only through Mendel and the application of his inheritance rules that “inner characteristics” were considered to achieve desired breeding results.
Ortrun Mittelsten Scheid of the Gregor Mendel Institute
Through Mendel, it is now possible to perform breeding based on molecular markers rather than only on visible and measurable traits,” explains Ortrun Mittelsten Scheid, Senior Group Leader at Vienna’s Gregor Mendel Institute: “This saves time, labor and costs, because we are no longer bound to growing organisms for a long time before selecting them for further generations.
RAPESEED: AN EDIBLE OIL RATHER THAN A LAMP OIL
A typical example and benefit of selective breeding in which Mendel’s rules were applied is rapeseed. Rapeseed oil was originally a bitter lamp oil. It was not until the 1970s that it became possible to breed rapeseed varieties suitable to generate oil for cooking. This required several steps over many years until the rapeseed plants produced both mild flavor and good yields.
The offspring of homozygous parents of different visible characteristics (due to different genetic makeups) all have the same characteristics. This is what Mendel described in the first rule of his major work, “Experiments on Plant Hybrids.” This is precisely what is exploited today by using such hybrids, produced by crossing defined parent varieties, as crops or livestock. In addition to their reliable uniformity, these offspring are often higher-yielding, more resistant and of better quality. This is known in genetics as the heterosis effect.
Examples include corn in plants or chickens in animals.
HUMAN GENETIC COUNSELING
However, Mendel’s findings are not only applied in agriculture, but also in human medicine. Cystic fibrosis is a hereditary metabolic disease caused by a genetic defect: viscous mucus is formed in many organs. The symptoms have their onset in early childhood and worsen progressively.
The genetic factor also applies to phenylketonuria, a congenital enzyme deficiency that can lead to mental developmental disorders if left untreated. “Both hereditary diseases are caused by defects in a single gene. As a result, they have well-predictable inheritance probabilities that facilitate human genetic counseling,” Mittelsten Scheid says.
In the 20th century, genetics rose to become the central discipline of the life sciences. This was made possible by a former substitute teacher, priest, and researcher with his experiments in a monastery garden: Gregor Mendel.
Dieter Schweizer, Founding Director of the Gregor Mendel Institute | ©GMI