Featured Research

from universities, journals, and other organizations

Cloned Crops Closer To Being Realized

Date:
June 10, 2009
Source:
Public Library of Science
Summary:
Clonal reproduction of crop species took a step closer to being realized with new research. The advantage of clonal reproduction is that it produces an individual exactly like an existing one -- very useful for farmers who could replicate the best of their animals or crops without the lottery of sexual reproduction.

No human is a clone of their parents but the same cannot be said for other living things. While your DNA is a combination of half your mother and half your father, other species do things differently. The advantage of clonal reproduction is that it produces an individual exactly like an existing one—which would be very useful for farmers who could replicate the best of their animals or crops without the lottery of sexual reproduction. Clonal reproduction of crop species took a step closer to being realised with new research published in PLoS Biology.

The type of cell division that creates eggs and sperm is called meiosis, and it differs from 'normal' cell division (mitosis) because instead of producing two genetically identical daughter cells, it produces four cells each containing only half of the parental amount of DNA. Meiosis occurs in all species that reproduce sexually, from microorganisms such as yeast to plants, animals and human beings. This new paper blurs the line between the two different types of cell division by showing a plant where three specific mutations are experimentally combined. These divisions are normally meiotic – which make pollen and egg cells – and are replaced by mitotic divisions.

The work, by a team of researchers in France and Austria, is potentially very important commercially, because it makes the creation of stable new mutant crops—such as plants of a different colour, or with a different yield, etc.—much simpler. It is now much closer to being possible to reproduce a plant that produces perfect potatoes, maize or rice, without the lottery of reassortment that each meiotic division and ensuing fertilization introduces.

The first steps of both meiosis and mitosis are the replication of the dividing cell's DNA. Once replication has occurred, the chromosomes condense into tightly bound structures, and in mitosis these form an X shape in which each half of the X is a chromatid, comprising one complete copy of the chromosome. The double-chromatid chromosomes line up along the centre of the cell. In mitosis, the two chromatids are pulled apart—the X is divided along one axis of symmetry—and these then pass into two genetically identical daughter cells. In meiosis, there are two lining up and dividing phases. The first lining up is of homologous chromosomes—all chromosomes in an adult cell have a partner, members of the partnership coming from the mother and father of the cell—and these homologous chromosomes are each made up of two chromatids. The first division divides homologous pairs of chromosomes while the second meiotic division is just like the mitotic di vision: the chromosomes line up at the middle of the new cell and the chromatids divide at the centre of the X.

Thus the differences between mitosis and meiosis are that meiosis has two rounds of division; co-segregation of sister chromatids at the first division; and recombination that occurs during the first division—a swapping over process that adds more genetic diversity to offspring. The new work, led by Raphael Mercier, identifies a gene that controls one of these three features—entry into the second meiotic division—in the sexual plant Arabidopsis thaliana. By combining a mutation in this gene with two other previously described mutations—one that eliminates recombination and another that modifies chromosome segregation—the authors have created a strain of plant (called MiMe for 'mitosis instead of meiosis') in which meiosis is totally replaced by mitosis.

MiMe plants produce pollen and eggs that are genetically identical to their parent. If MiMe eggs are self-fertilized by MiMe sperm, the offspring plant has twice as much DNA as the parent generation, and has all the genes from this single parent.

Thus the authors have made a form of asexual reproduction possible in a normally sexual species. Turning meiosis into mitosis is not enough to reach clonal reproduction, but it's a giant leap towards it. This has potential revolutionary applications in crop improvement and propagation.

This work was supported by an INRA postdoctoral fellowship to Id'E. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. d'Erfurth et al. Turning Meiosis into Mitosis. PLoS Biology, 2009; 7 (6): e1000124 DOI: 10.1371/journal.pbio.1000124

Cite This Page:

Public Library of Science. "Cloned Crops Closer To Being Realized." ScienceDaily. ScienceDaily, 10 June 2009. <www.sciencedaily.com/releases/2009/06/090608204055.htm>.
Public Library of Science. (2009, June 10). Cloned Crops Closer To Being Realized. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2009/06/090608204055.htm
Public Library of Science. "Cloned Crops Closer To Being Realized." ScienceDaily. www.sciencedaily.com/releases/2009/06/090608204055.htm (accessed July 29, 2014).

Share This




More Plants & Animals News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins