抖阴黄版下载

抖阴黄版下载 (CSHL) has begun to unravel a mystery millennia in the making. Our story begins 9,000 years ago. It was then that maize was first domesticated in the Mexican lowlands. Some 5,000 years later, the crop crossed with a species from the Mexican highlands called teosinte mexicana. This resulted in cold adaptability. From here, corn spread across the continent, giving rise to the vegetable that is now such a big part of our diets. But how did it adapt so quickly? What biological mechanisms allowed the highland crop鈥檚 traits to take hold? Today, a potential answer emerges.

CSHL Professor and HHMI Investigator Rob Martienssen had been studying RNA interference, the process of small RNAs silencing genes, for more than 20 years when University of Wisconsin researcher Jerry Kermicle reached out with a curious observation. His experiments crossing semi-sterile teosinte hybrids with traditional maize had caused their offspring to behave very unusually. With normal inheritance, the offspring should have eventually become completely sterile or fertile. But no matter how many times Kermicle crossed the hybrids with maize, all the offspring were semi-sterile, too. What was happening?

To figure it out, Martienssen and graduate student Ben Berube sequenced the genomes from hundreds of pollen grains of the semi-sterile offspring. They discovered the same sections from the teosinte genome were present in each. Martienssen says:

鈥淭丑别re were two pieces of the genome, one on chromosome 5 and one on chromosome 6, that were always inherited. That told us the genes responsible must be in those regions.鈥�

On chromosome 5, they found that a gene called Dicer-like 2 makes a group of small RNAs that are always in semi-sterile hybrids but not traditional maize. With that finding, the Martienssen lab was able to pinpoint what they call Teosinte Pollen Drive (TPD). This 鈥渟elfish鈥� genetic system eliminates competing pollen grains that lack the gene drive. It causes maize-teosinte hybrids to pass certain traits through males more often than females. The discovery could have significant implications for the agriculture industry. But in Martienssen鈥檚 eyes, the finding is even bigger than its potential weed control applications:

鈥淚鈥檓 more excited by the evolutionary aspects, what it might mean for the process of domestication, and how it could have been much quicker than we thought.鈥�

If teosinte mexicana is 鈥渢he Neanderthal of maize,鈥� Martienssen may have found in TPD corn鈥檚 鈥渕issing link.鈥� The breakthrough could explain how corn came to thrive across America鈥攂ut also why certain small RNAs are so common in plant and animal sperm cells, including ours.

Written by: Margaret Osborne, Science Writer | publicaffairs@cshl.edu | 516-367-8455

Funding

National Institutes of Health, National Science Foundation Plant Genome Research Program, Howard Hughes Medical Institute, National Science Foundation

Citation

Berube, B., et al., 鈥�Teosinte Pollen Drive guides maize diversification and domestication by RNAi鈥�, Nature, August 7, 2024. DOI:

Core Facilites

鈥淭丑别 Flow Cytometry Shared Resource offers researchers equipment, training, and assistance with cellular analysis for a variety of applications as well as cell sorting. Our staff oversees equipment maintenance and quality control, trains new users on instrument operation, and assists with assay development and data analysis. We also provide tissue culture facilities for sample preparation and cell maintenance during ongoing flow cytometry experiments.鈥� 鈥� Director Pamela Moody

鈥淭丑别 Microscopy Core Facility provides training, consultation, experimental design and technical assistance to investigators at CSHL in widefield, spinning disk laser scanning or point laser scanning confocal fluorescence microscopy, and super-resolution microscopy. In addition, the Microscopy Shared Resource provides customized state-of-the-art optical imaging and quantitative image analysis applications to support a wide range of scientific endeavors.鈥� 鈥� Director Erika Wee, Ph.D.

鈥淭丑别 Sequencing Technologies and Analysis Shared Resource provides access to an array of high throughput Next Generation Sequencing (NGS) technologies. We offer cutting-edge technology alongside convenient in-house services for a broad range of genetic analysis.鈥� 鈥� Project Manager Sara Goodwin, Ph.D.