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 September 30, 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 September 30, 2014).

Share This



More Health & Medicine News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How 'Yes Means Yes' Defines Sexual Assault

How 'Yes Means Yes' Defines Sexual Assault

Newsy (Sep. 29, 2014) Aimed at reducing sexual assaults on college campuses, California has adopted a new law changing the standard of consent for sexual activity. Video provided by Newsy
Powered by NewsLook.com
Scientists May Have Found An Early Sign Of Pancreatic Cancer

Scientists May Have Found An Early Sign Of Pancreatic Cancer

Newsy (Sep. 29, 2014) Researchers looked at 1,500 blood samples and determined people who developed pancreatic cancer had more branched chain amino acids. Video provided by Newsy
Powered by NewsLook.com
Colo. Doctors See Cluster of Enterovirus Cases

Colo. Doctors See Cluster of Enterovirus Cases

AP (Sep. 29, 2014) Doctors at the Children's Hospital of Colorado say they have treated over 4,000 children with serious respiratory illnesses since August. Nine of the patients have shown distinct neurological symptoms, including limb weakness. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Dr.'s Unsure of Cause of Fast-Spreading Virus

Dr.'s Unsure of Cause of Fast-Spreading Virus

AP (Sep. 29, 2014) Doctors at the Children's Hospital of Colorado say they have treated over 4,000 children with serious respiratory illnesses since August. Nine of the patients have shown distinct neurological symptoms, including limb weakness. (Sept. 29) 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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