Navigation Links
Disabling mouse enzyme increases fertility
Date:5/16/2008

St. Louis, May 16, 2008 Changing the sugars attached to a hormone produced in the pituitary gland increased fertility levels in mice nearly 50 percent, a research group at Washington University School of Medicine in St. Louis has found. The change appears to alter a reproductive "thermostat," unveiling part of an intricate regulatory system that may one day be used to enhance human fertility.

"To adjust for the right amount of key reproductive hormones such as estrogen and testosterone, we may someday alter the sugars that are added to this hormone or others like it," says the group's leader, Jacques Baenziger, M.D., Ph.D., professor of pathology and immunology and of cell biology and physiology.

The report appeared recently in The Journal of Clinical Investigation.

Sugars are the most common addition to hormones and other proteins after they have been assembled from instructions in DNA. Nearly all proteins in the blood and on the surface of cells have sugars attached. Scientists believe sugar attachments modify and adapt proteins, enabling them to fill more than one job or changing the way they do their jobs in different contexts. But direct demonstration of such changes has been challenging.

Baenziger found a unique set of sugars consistently added to luteinizing hormone, which is part of a feedback loop between the pituitary, the reproductive organs and the liver. The loop cycles up and down over time, producing periodic peaks in other reproductive hormones and triggering regular events such as the ovaries' release of eggs.

For their study, Baenziger's laboratory genetically disabled one of the enzymes that attaches sugars to luteinizing hormone in mice. This enzyme isn't the only one to add sugars to the hormone, so the alteration changes the mix of sugars rather than eliminating them completely.

Initially, we didnt seem to see much of a difference in the animals, Baenziger says. But then someone came to me and said, We have too many animals. Were constantly weaning mice!

A closer look showed that the mice were having nearly 50 percent more pups than normal, and that the liver removed the altered hormone from the blood more slowly. In addition, female mice were maturing earlier, were always receptive to male overtures for mating and had a disrupted ovulatory cycle. Males had higher levels of testosterone and females had higher levels of estrogen. Surprisingly, the altered female mice were also better mothers: They ate their pups less often.

"One could speculate that fertility problems in some humans may be partly related to a defect somewhere in this very complicated regulatory system," says Baenziger. "They may have the wrong proportion of some of these sugars, or the receptors that clear the sugar-hormone combination from the blood might not bind as well."

Baenziger, who recently won a five-year, $3.3 million grant renewal from the National Cancer Institute, wants to learn more about the segments in the reproductive hormones that single them out for the addition of unique sugars. He hopes to use that information to search for other proteins that receive similar treatment.

"We know these systems for adding sugars are well-regulated, but we're just starting to get a sense for how they are controlled and how far-reaching their effects can be," he says. "I think we're going to see much more of this kind of alteration and regulation of protein properties via added sugars in many other important areas of biology."


'/>"/>

Contact: Michael Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
Source:Eurekalert

Related biology news :

1. Study reveals 2 genes linked to disabling arthritis
2. Mouse can do without mans most treasured genes
3. Mouse study: When it comes to living longer, its better to go hungry than go running
4. Negligent, attentive mouse mothers show biological differences
5. Scientists successfully treat new mouse model of inflammatory bowel disease
6. Book is the first high-resolution digital mouse brain atlas designed for Web applications
7. Dissecting the genetic components of adaptation of E. coli to the mouse gut
8. CSHL scientists identify and repress breast cancer stem cells in mouse tissue
9. New chimeric mouse model for human liver diseases, drug testing
10. Looking through the eyes of a mouse, scientists monitor circulating cells in its bloodstream
11. Cancer-resistant mouse discovered
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/2/2016)... -- Perimeter Surveillance & Detection Systems, Biometrics ... Support & Other Service  The latest report ... analysis of the global Border Security market . ... $17.98 billion in 2016. Now: In November ... software and hardware technologies for advanced video surveillance. ...
(Date:5/16/2016)... --  EyeLock LLC , a market leader of iris-based ... IoT Center of Excellence in Austin, Texas ... embedded iris biometric applications. EyeLock,s iris authentication ... with unmatched biometric accuracy, making it the most proven ... platform uses video technology to deliver a fast and ...
(Date:4/28/2016)... FRANCISCO and BANGALORE, India , ... of EdgeVerve Systems, a product subsidiary of Infosys (NYSE: ... provider, today announced a global partnership that will ... way to use mobile banking and payment services. ... is a key innovation area for financial services, but it ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... (PRWEB) , ... June 27, 2016 , ... ... published their findings on what they believe could be a new and helpful ... the new research. Click here to read it now. , Biomarkers ...
(Date:6/27/2016)... Raleigh, NC (PRWEB) , ... June 27, 2016 ... ... a mission to bring innovative medical technologies, services and solutions to the healthcare ... development and implementation of various distribution, manufacturing, sales and marketing strategies that are ...
(Date:6/27/2016)... -- Liquid Biotech USA , Inc. ... Research Agreement with The University of Pennsylvania ("PENN") ... patients.  The funding will be used to assess ... outcomes in cancer patients undergoing a variety of ... to support the design of a therapeutic, decision-making ...
(Date:6/24/2016)...  Regular discussions on a range of subjects including policies, ... entities said Poloz. Speaking at a lecture to ... he pointed to the country,s inflation target, which is set ... "In certain areas there needs ... economic goals, why not sit down and address strategy together?" ...
Breaking Biology Technology: