Featured Research

from universities, journals, and other organizations

From Embryo To Placenta, Gene Transfer In Primates A Success

Date:
September 11, 2001
Source:
University Of Wisconsin-Madison
Summary:
By successfully inserting a gene from a jellyfish into the fertilized eggs of rhesus monkeys, scientists have managed to make transgenic placentas, placentas where the inserted gene functions as it does in the jellyfish.

MADISON - By successfully inserting a gene from a jellyfish into the fertilized eggs of rhesus monkeys, scientists have managed to make transgenic placentas, placentas where the inserted gene functions as it does in the jellyfish.

Writing today, Sept. 11, in the Proceedings of the National Academy of Sciences, Thaddeus G. Golos of the Wisconsin Regional Primate Research Center at the University of Wisconsin-Madison, described the successful insertion of a "reporter gene" into two fertilized rhesus macaque embryos. The gene, which causes jellyfish cells to produce a robust green glow, likewise conferred this activity on the placental cells where it was found.

"The infants produced here did not carry the gene in their DNA," Golos says, "but they did carry it and produce large amounts of the transgenic protein within their placentas during pregnancy."

In mammals, the placenta develops in the uterus from the embryo during gestation. Its role is to provide nourishment to the developing fetus and to transfer fetal wastes to the maternal circulation.

This new work, Golos says, will help provide a way to explore the role that individual genes play in pathologies of pregnancy. It promises new insight into such problems in maternal and fetal health as infertility, recurrent spontaneous miscarriage, and fetal growth and low birth weight.

"These are the most important issues in terms of a healthy pregnancy," Golos says. "A healthy placenta is a requirement for a healthy fetus. Placental defects and problems are the causes of significant fetal and maternal morbidity and mortality."

Because the green-glow gene can be seen in cells, it is a much used "reporter" gene that can tell scientists that it has been effectively delivered to the host cell.

The work reported today by the Wisconsin group is important because it is the first time a gene that has been transferred into a primate embryo has been shown to be functional throughout development to a successful live birth. It also demonstrates that successful pregnancy is possible when genes foreign to the mother are engineered into the embryos of nonhuman primates.

The Wisconsin group adapted technology currently in development for human gene therapy by using extensively modified components of the genetic material of HIV as a vector to ferry the gene into the cells of early-stage rhesus monkey embryos. The vector, Golos says, is stripped of disease-causing genes and employs just a small percentage of the HIV genome to trick embryonic cells into accepting the transgene.

In effect, Golos says, the vector, which was developed by Robert G. Hawley at the American Red Cross Holland Laboratory, is used to "package the transgene into a noninfectious viral particle, and to allow the transgene to be inserted into the genome of the embryo."

The engineered embryos were then implanted in surrogate rhesus macaque mothers and carried to term. One of the pregnancies resulted in twins, but only one twin survived to term. Twin pregnancies are rare in rhesus monkeys.

Because rhesus macaques are genetically very close to humans, the work underscores the potential of the rhesus macaque as a model for future studies to establish the safety and effectiveness of human gene and stem cell therapy. The work is just a small step away from making a truly transgenic monkey, where foreign DNA is not only transferred from one species to another but is functional as well. A more immediate consideration, Golos says, is that the accomplishment forms the basis for new experimental insights into placental health and function.

Last January, a group at the Oregon Regional Primate Research Center reported the birth of a single rhesus monkey carrying transgenic DNA. Although the Oregon monkey carried the foreign DNA, the introduced DNA did not produce the protein that the transgene is supposed to make.

"This is an important distinction," Golos says, "since the success of transgenic or gene transfer studies is determined by whether or not the protein is produced."

Golos notes that the surrogate mothers carrying the engineered embryos developed antibodies to the jellyfish protein at about mid-pregnancy. Despite this immune response, the pregnancies were carried successfully to term, demonstrating that primate embryos with working transgenes are a viable experimental model for exploring how the maternal immune system accepts the fetus, whose genes are, in part, inherited from the father.

"Scientists can now devise experiments to learn the role of individual genes in human female reproductive health, and maternal and fetal well-being," Golos says.

Co-authors of the paper include M.J. Wolfgang, S.G. Eisele, M.A. Browne, M.L. Schotzko, M.A. Garthwaite, M Durning and J.A. Thomson, all of UW-Madison; and A. Ramezani and R.G. Hawley of the American Red Cross.

The Holland Laboratory is the research and development division of American Red Cross Biomedical Services, supporting the organization's Blood, Tissue and Plasma Services, and the Center for Cellular Therapy.The work of the Wisconsin team was supported by the National Institutes of Health.


Story Source:

The above story is based on materials provided by University Of Wisconsin-Madison. Note: Materials may be edited for content and length.


Cite This Page:

University Of Wisconsin-Madison. "From Embryo To Placenta, Gene Transfer In Primates A Success." ScienceDaily. ScienceDaily, 11 September 2001. <www.sciencedaily.com/releases/2001/09/010911072827.htm>.
University Of Wisconsin-Madison. (2001, September 11). From Embryo To Placenta, Gene Transfer In Primates A Success. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2001/09/010911072827.htm
University Of Wisconsin-Madison. "From Embryo To Placenta, Gene Transfer In Primates A Success." ScienceDaily. www.sciencedaily.com/releases/2001/09/010911072827.htm (accessed September 19, 2014).

Share This



More Health & Medicine News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
How The 'Angelina Jolie Effect' Increased Cancer Screenings

How The 'Angelina Jolie Effect' Increased Cancer Screenings

Newsy (Sep. 19, 2014) Angelina's Jolie's decision to undergo a preventative mastectomy in 2013 inspired many women to seek early screenings for the disease. Video provided by Newsy
Powered by NewsLook.com
The Cost of Ebola

The Cost of Ebola

Reuters - Business Video Online (Sep. 18, 2014) As Sierra Leone prepares for a three-day "lockdown" in its latest bid to stem the spread of Ebola, Ciara Lee looks at the financial implications of fighting the largest ever outbreak of the disease. Video provided by Reuters
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