Navigation Links
The genetic origins of corn on the cob

In 1909, while harvesting a typical corn crop (Zea mays) in Illinois, a field worker noticed a plant so unusual that it was initially believed to be a new species. Its "peculiarly shaped ear" was "laid aside as a curiosity" and the specimen was designated Zea ramosa (from the Latin ramosus, "having many branches"). Due to the alteration of a single gene, later named ramosa1, both the ear and the tassel of the plant were more highly branched than usual, leading to loose, crooked kernel rows and to a tassel that was far bushier than the tops of normal corn plants.

Now, researchers at Cold Spring Harbor Laboratory in New York have isolated the ramosa1 gene and shown how it controls the arrangement and length of flower-bearing branches in corn, related cereal crops, and ornamental grasses. The study indicates that during the domestication of corn from its wild ancestor (teosinte), early farmers selected plants with special versions of the ramosa1 gene that suppressed branching in the ear, leading to the straight rows of kernels and the compact ears of modern-day corn on the cob. The findings are described in the July 24 advance online edition of the journal Nature.

"We've shown that corn and related grasses have either none, some, or a lot of ramosa1 gene activity, and that these different levels of activity have a big impact on the architecture of the plants," says Dr. Robert Martienssen of Cold Spring Harbor Laboratory, who led the study. "The ramosa1 gene appears to be a key player in the domestication of corn, and we've shown that it acts by signaling cells to form short rather than long branches," says Martienssen, who was joined in the study by lead author Dr. Erik Vollbrecht, now at Iowa State University.

Says Vollbrecht, "We solved this enduring puzzle by combining classical and modern molecular genetics. The former included our use of transposable elements or 'jumping genes'--discovered at Cold Spring Harbor by [Nobel laureate] Barbara Mc Clintock--to 'tag' the ramosa1 gene. That enabled us to isolate the gene and determine its DNA sequence for a variety of other experiments."

"As corn was being domesticated, farmers selected a larger and larger ear with more and more rows of kernels, based on the activity of genes other than ramosa1. But we suspect that as the ear got larger, it needed special alleles of ramosa1 to prevent the extra rows from forming branches instead of kernels," says Martienssen. "There may have been other reasons for selecting an unbranched ear, including the interaction with other genes that were subsequently lost during domestication, but we don't yet know if this is the case."

The study reveals that plants with more ramosa1 activity (e.g. typical corn) tend to have fewer branches, shorter branches, and fewer flowers whereas plants with less ramosa1 activity (e.g. sorghum, rice, and the ramosa corn variety described above) tend to have more branches, longer branches, and more flowers.

"We also looked at a popular ornamental grass that grows outside my office and found the same result. It has a spiky top like corn, so we were delighted to find that they have similar profiles of ramosa1 activity," says Martienssen.


Source:Cold Spring Harbor Laboratory

Related biology news :

1. Its not all genetic: Common epigenetic problem doubles cancer risk in mice
2. Scientists detect probable genetic cause of some Parkinsons disease cases
3. Mouse brain tumors mimic those in human genetic disorder
4. Scientists identify genetic pathways essential to RNA interference
5. Researchers trace evolution to relatively simple genetic changes
6. Key mechanism in genetic inheritance during cell division identified
7. Scientists identify genetic pathways essential to RNA interference
8. MUHC scientists describe genetic resistance to rampant virus
9. Mosaic mouse technique offers a powerful new tool to study diseases and genetics
10. Montreal researchers probe the genetic basis of memory
11. Biologists determine genetic blueprint of social amoeba
Post Your Comments:

(Date:10/29/2015)... ANN ARBOR, Mich. , Oct. 29, 2015 ... with Eurofins Genomics for U.S. distribution of its ... DNA-seq kit and Rubicon,s new ThruPLEX Plasma-seq ... DNA to enable the preparation of NGS libraries ... in plasma for diagnostic and prognostic applications in ...
(Date:10/29/2015)... YORK , Oct. 29, 2015 ... technology, announced a partnership with 2XU, a global ... to deliver a smart hat with advanced bio-sensing ... and other athletes to monitor key biometrics to ... the strategic partnership, the two companies will bring together ...
(Date:10/27/2015)... 27, 2015 Synaptics Inc. (NASDAQ: SYNA ), ... Google has adopted the Synaptics ® ClearPad ® ... power its newest flagship smartphones, the Nexus 5X by ... --> --> Synaptics works ... strategic collaboration in the joint development of next generation ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... -- Clintrax Global, Inc., a worldwide provider of clinical research services headquartered ... the company has set a new quarterly earnings record in Q3 ... posted for Q3 of 2014 to Q3 of 2015.   ... , with the establishment of an Asia-Pacific ... United Kingdom and Mexico , with ...
(Date:11/24/2015)... SHPG ) announced today that Jeff Poulton , ... Annual Healthcare Conference in New York City ... (1:30 p.m. GMT). --> SHPG ) announced today that ... Piper Jaffray 27 th Annual Healthcare Conference in ... at 8:30 a.m. EST (1:30 p.m. GMT). --> Shire ...
(Date:11/24/2015)... 2015  Twist Bioscience, a company focused on ... Twist Bioscience chief executive officer, will present at ... 1, 2015 at 3:10 p.m. Eastern Time at The Lotte ... --> --> About ... is on Twitter. Sign up to follow our ...
(Date:11/24/2015)... , Nov. 24, 2015 /CNW Telbec/ - ProMetic Life Sciences ... today that Mr. Pierre Laurin , President and Chief ... at the upcoming Piper Jaffray 27 th Annual Healthcare ... on December 1-2, 2015. st , at ... one-on-one meetings throughout the day. The presentation will be available ...
Breaking Biology Technology: