Navigation Links
Plants defy Mendel's inheritance laws, may prompt textbook changes

Contrary to inheritance laws the scientific world has accepted for more than 100 years, some plants revert to normal traits carried by their grandparents, bypassing genetic abnormalities carried by both parents.

These mutant parent plants apparently have hidden templates containing genetic information from the preceding generation that can be transferred to their offspring, even though the traits aren't evident in the parents, according to Purdue University researchers. This discovery flies in the face of the scientific laws of inheritance first described by Gregor Mendel in the mid-1800s and still taught in classrooms around the world today.

"This means that inheritance can happen more flexibly than we thought in the past," said Robert Pruitt, a Purdue Department of Botany and Plant Pathology molecular geneticist. "While Mendel's laws that we learned in high school still are fundamentally correct, they're not absolute.

"If the inheritance mechanism we found in the research plant Arabidopsis exists in animals, too, it's possible that it will be an avenue for gene therapy to treat or cure diseases in both plants and animals."

The study is published in the March 24 issue of the journal Nature.

Pruitt and collaborator Susan Lolle found that Arabidopsis in which each parent plant had two copies of a mutant gene could produce progeny that didn't show the parents' deformity, but rather were normal like the grandparents. Under Mendelian laws, the offspring should have shown the same mutation.

The first clue that the classic inheritance rules didn't always apply was the discovery of normal flowers on some offspring of mutant plants. In the deformed parents, the flowers were fused into tight balls. But in the grandparents and 10 percent of the grandchildren, the buds become 1-millimeter-long, bright white flowers that fully opened and radiated out from the center of a cluster.

"If you take this mutant Arabidopsis, which has two copies of the altered gene, let it seed and then plant the seeds, 90 percent of the offspring will look like the parent, but 10 percent will look like the normal grandparents," Pruitt said. "Our genetic training tells us that's just not possible. This challenges everything we believe.

"We've done a lot of experiments, described in this paper, that show none of the simple explanations account for this skipping of generations by an inherited trait."

The scientists kept the plants in isolation so they couldn't accidentally crossbreed with plants that didn't have the mutated gene, called hothead, that causes organ fusion like that seen in the flowers. The researchers used molecular markers - bits of DNA that help identify and locate genes in organisms - to determine whether a plant carried normal or mutant copies of the genes.

"It seems that these hothead-containing plants keep a cryptic copy of everything that was in the previous generation, even though it doesn't show up in the DNA, it's not in the chromosome," Pruitt said. "Some other type of gene sequence information that we don't really understand yet is modifying the inherited traits."

Although the hothead gene tipped the researchers off to this unconventional inheritance cycle, Pruitt believes that this particular DNA sequence is just a trigger for the phenomenon. He suspects that a number of other genes and the proteins they produce are involved in activating this process.

"We need to understand more about the molecular mechanics of how this process works," Pruitt said. "Then we will know exactly what role this gene plays."

Pruitt's team already knows that animals don't have hothead genes, either normal or mutated, so the scientists must investigate which genes might affect this novel inheritance in both plants and animals.

"There are probably a lot of other triggers yet to be discovered, and this mechanism for inheritance may require a different tr igger to make it work in animals," he said.

Once scientists understand more about the mechanism, they then may be able to manipulate it to modify genes already in plants and animals in order to correct mutations that cause diseases and abnormal growth.

Though further research is required to learn how this form of inheritance happens and how it can help improve plants or animals through gene therapy, Pruitt said the discovery has opened an important new line of thinking.

The other researchers involved with this study were Jennifer Victor, a former Purdue graduate student now at Butler University; and Jessica Young, a botany and plant pathology laboratory technician. Lolle, a Purdue research scientist, is currently at the National Science Foundation.


Source:Purdue University

Related biology news :

1. Quantum Dots Research Leads to New Knowledge about Protein Binding in Plants
2. Plants, animals share molecular growth mechanisms
3. Plants respond similarly to signals from friends, enemies
4. Study: Plants use dual defense system to fight pathogens
5. Plants discriminate between self and non self
6. Prozac for future Plants on Mars
7. Plants reveal a secret and bring researchers nearer a cleaner future
8. Plants have a double line of defence
9. Plants, too, have ways to manage freeloaders
10. Plants give pests sock in the gut
11. Plants used to detect gas leaks, from outer space!
Post Your Comments:

(Date:6/27/2016)... Research and Markets has announced the addition of the ... The report forecasts the biometrics ... a CAGR of 12.28% during the period 2016-2020. ... with inputs from industry experts. The report covers the market landscape ... includes a discussion of the key vendors operating in this market. ...
(Date:6/22/2016)... -- The American College of Medical Genetics and Genomics was once ... one of the fastest-growing trade shows during the Fastest 50 ... Las Vegas . Winners ... each of the following categories: net square feet of paid ... The 2015 ACMG Annual Meeting was ranked 23 out of ...
(Date:6/22/2016)... LOS ANGELES , June 22, 2016 ... of identity management and verification solutions, has ... cutting edge software solutions for Visitor Management, ... ® provides products that add functional ... The partnership provides corporations and venues with ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... -- Alex,s Lemonade Stand Foundation (ALSF), a leading national childhood ... state-of-the-art bioinformatics lab, using ,big data, to advance the ... Liz Scott , co-executive director of ALSF and ... Washington, D.C. , hosted by Vice ... of pediatric cancer research and awareness. ...
(Date:6/27/2016)... 2016  Global demand for enzymes is forecast ... to $7.2 billion.  This market includes enzymes used ... biofuel production, animal feed, and other markets) and ... Food and beverages will remain the largest market ... of products containing enzymes in developing regions.  These ...
(Date:6/27/2016)... , June 27, 2016 /PRNewswire/ - BIOREM Inc. (TSX-V: BRM) ... advised by its major shareholders, Clean Technology Fund I, ... United States based venture capital funds which ... Biorem (on a fully diluted, as converted basis), that ... of their entire equity holdings in Biorem to TUS ...
(Date:6/27/2016)... 2016  Sequenom, Inc. (NASDAQ: SQNM ), ... through the development of innovative products and services, announced ... United States denied its petition to review ... Sequenom,s U.S. Patent No. 6,258,540 (",540 Patent") are not ... the Supreme Court,s Mayo Collaborative Services v. Prometheus Laboratories ...
Breaking Biology Technology: