Featured Research

from universities, journals, and other organizations

From embryonic stem cells, a sperm replacement and easier path to genetic modification

Date:
April 26, 2012
Source:
Cell Press
Summary:
Not only will the advance make it easier to produce genetically modified mice, but it may also enable genetic modification of animals that can't be modified by today's means. The technique might ultimately be used in assisted human reproduction for those affected by genetic disease, the researchers suggest.

This image shows two eight-week-old SC mice derived from ICAHCI of AGH-OG-2 cells.
Credit: Yang et al. in the journal Cell.

Researchers reporting in the April 27 issue of the journal Cell have devised a new and improved method for producing genetically modified animals for use in scientific research. The method relies on haploid embryonic stem cells (haESCs) instead of sperm to artificially fertilize immature egg cells. Such stem cells are similar to sperm in that they carry only genetic material from a mouse "dad."

Not only will the advance make it easier to produce genetically modified mice, but it may also enable genetic modification of animals that can't be modified by today's means. The technique might ultimately be used in assisted human reproduction for those affected by genetic disease, the researchers suggest.

"The current procedure to generate genetically modified animals is tedious and very inefficient," said Jinsong Li of the Shanghai Institute for Biological Sciences. "We thought if we can generate haploid embryonic stem cells and produce semicloned animals by simply injecting those cells into oocytes, we would be certain to get a transmission into offspring with limited breeding as half of the progeny will inherit the genetic modification."

Currently, genetically modified mice are made from embryonic stem cells carrying two copies of every gene, one from mom and one from dad. These diploid embryonic cells are injected into blastocysts early in development to produce chimeras, animals whose tissues are made up of cells with one of two genomic identities. As the modified genome is randomly incorporated into the cells that will give rise to eggs and sperm, genetic modifications have the possibility to be passed on to future generations. But it's a slow and uncertain process.

Now, Jinsong Li, Guo-Liang Xu and their colleagues have found a way to generate haploid embryonic stem cells (haESCs) that can be used in place of sperm. They produce these specialized cells by first removing the nucleus from immature eggs (oocytes) and then injecting them withsperm. This procedure produces haESCs that partially retain chemical modifications characteristic of the paternal line -- enough that they can be successfully used in place of sperm.

The researchers successfully produce live mice bearing haESC-carried genetic traits. These animals, which they call "semicloned mice," grew into fertile adults.

"By being amenable to gene manipulations and supporting transmission of genetic information to offspring, these haploid cells open new avenues for the generation of genetically modified animals," the researchers write. The next challenge is to improve the sperm-like features of the haESCs by optimizing their makeup without otherwise compromising them.

The new method might also lead to genetic modification of animals, such as monkeys, that have been off limits because they don't support the production of chimeras, Li says.

As for human reproduction, right now the haESCs are clearly not as good as sperm for the purposes of IVF, but they could someday have advantages. "A similar technique might be one day used to correct genetic disease in germ cells in humans to have a healthy baby for parents," Li said.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Hui Yang, Linyu Shi, Bang-An Wang, Dan Liang, Cuiqing Zhong, Wei Liu, Yongzhan Nie, Jie Liu, Jing Zhao, Xiang Gao, Dangsheng Li, Guo-Liang Xu, Jinsong Li. Generation of Genetically Modified Mice by Oocyte Injection of Androgenetic Haploid Embryonic Stem Cells. Cell, 2012; 149 (3): 605 DOI: 10.1016/j.cell.2012.04.002

Cite This Page:

Cell Press. "From embryonic stem cells, a sperm replacement and easier path to genetic modification." ScienceDaily. ScienceDaily, 26 April 2012. <www.sciencedaily.com/releases/2012/04/120426135234.htm>.
Cell Press. (2012, April 26). From embryonic stem cells, a sperm replacement and easier path to genetic modification. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2012/04/120426135234.htm
Cell Press. "From embryonic stem cells, a sperm replacement and easier path to genetic modification." ScienceDaily. www.sciencedaily.com/releases/2012/04/120426135234.htm (accessed April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. Video provided by Newsy
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