Navigation Links
Dad's Genes May Play Greater Role Than Thought
Date:6/15/2009

Data on 'packaging' in sperm cells may also help assess infertility,,

MONDAY, June 15 (HealthDay News) -- Biologists say they have discovered a clever packaging scheme that allows the genetic material in sperm to have far more influence over development of a fertilized egg than had been imagined.

The discovery has potential applications in helping infertile men, said Brad Cairns, a professor of oncological sciences at the University of Utah and a leader of the team reporting the finding in the June 14 online edition of Nature.

The vast majority of the DNA molecules that carry genetic information are tightly packaged in sperm cells, Cairns said. That tight packaging enables a win in what is literally a race for life because the first sperm to reach an egg fertilizes it, and the tightest packages are the most streamlined.

"But when it comes to development, the sperm is at a real disadvantage," Cairns said. "The vast majority of their genes are tightly packed in material that is not helpful in giving them full expression."

In every cell other than sperm, DNA molecules are wrapped around structures called histones, an arrangement that allows for easy transmission of their genetic instructions. But only 4 percent of sperm DNA is arranged around histones. The other 96 percent is in a dense, impenetrable material called protamine.

"The hypothesis has been that this 4 percent of DNA in histones is randomly distributed," Cairns said. "We challenged the hypothesis and found that the DNA that is in histones is not randomly distributed but is located at important genes for embryonic development."

The discovery was made by using DNA from sperm at the University of Utah's in vitro fertilization clinic. "We isolated the DNA attached to histones and sequenced it," Cairns said. "We found genes that are important in guiding the development of the embryo."

The discovery raises "obvious questions" about the importance of DNA packaging in sperm on human fertility, he said.

"Do infertile men have problems in packaging, and is that the basis of their problem?" Cairns asked. "We already have preliminary evidence that the majority of infertile men have problems in gene packaging. There is an incorrect ratio of histones to protamine."

Cairns said that the gene packaging issue is related to another biological aspect of DNA expression -- DNA methylation. Some subunits of the DNA molecules ordinarily have molecules called methyl groups attached to them. Lack of methylation can also contribute to infertility, he said.

The Utah group is working on a test that could define the root issues in men with fertility problems, Cairns said. "We are working toward a clinical diagnostic test for infertile men that would assess their packaging and DNA methylation status so that we could counsel them on whether they can have success in achieving fertility," he said.

The concept of possible intervention to improve fertility is much more distant, he said.

From the basic science point of view, one major lesson of the discovery is that DNA is not the only molecule that can carry genetic information from generation to generation, said William G. Kelly, an associate professor of biology at Emory University, whose review article will appear in the same issue of the journal.

What the study shows "is that the histones still sitting there have really important information that actually guides the genes that regulate early events in the development of the next generation," Kelly said.

That idea has been proposed, but "it was not clear that this information could survive the packaging in sperm," he said.

"This firmly shows that information that's there can be information that is passed across generations and that is not encoded in DNA," Kelly said.

More information

The Yale Fertility Center has more on the causes and treatment of infertility.



SOURCES: Bradley Cairns, Ph.D., professor, oncological sciences, University of Utah, Salt Lake City; William G. Kelly, Ph.D., associate professor, biology, Emory University, Atlanta; June 14, 2009, Nature, online


'/>"/>
Copyright©2009 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Parents of Murdered Dating Violence Victim, Legislators, and Teachers Unite to Launch MADE - Moms and Dads for Education to Stop Teen Dating Abuse
2. Bounty Launches New Survival Guide Website for Dads
3. Massage Chairs Promote Comfort and Happy Dads for Fathers Day
4. Fathers Day is Almost Here: Two Pediatric Nurses, Moms, Offer Practical Guidebook & DVD for New Dads
5. Dads Early-Onset Obesity Linked to Liver Disease in Kids
6. Dads Substance Use Hurts Expectant Moms Efforts to Quit
7. Some moms quit cigarettes, marijuana, alcohol during pregnancy, but dads dont
8. Dads break bones of children more often than moms
9. Having Lots of Kids Helps Dads Live to 100
10. A breakthrough in gastric carcinogenesis
11. Innovative New Wellness and Nutrition Program Leverages Latest Understanding of Relationship Between Diet and Genes
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Dad's Genes May Play Greater Role Than Thought
(Date:10/13/2017)... ... 2017 , ... The International Association of Eating Disorders Professionals ... the field of eating disorders, announces the opening of early registration for the ... at the Omni Resort at ChampionsGate. , The annual iaedp™ Symposium ...
(Date:10/13/2017)... , ... October 13, 2017 , ... Lori R. Somekh, ... member of ElderCounsel, a national organization of elder law and special needs planning attorneys. ... and rules. It also provides a forum to network with elder law attorneys nationwide,” ...
(Date:10/13/2017)... ... October 13, 2017 , ... The Visiting Nurse Association (VNA) of Somerset ... of specialty vendors and unique items from across the nation, this holiday-themed event will ... services offered by the VNA. The boutique will be open Saturday, November 4 ...
(Date:10/13/2017)... ... October 13, 2017 , ... Yisrayl Hawkins, Pastor and Overseer ... one of the most popular and least understood books in the Holy Scriptures, Revelation. ... descriptions that have baffled scholars for centuries. Many have tossed it off as mere ...
(Date:10/13/2017)... ... ... “The Journey: From the Mountains to the Mission Field”: the story of ... Philippines. “The Journey: From the Mountains to the Mission Field” is the creation of ... taught all ages and currently teaches a class of ladies at her church, which ...
Breaking Medicine News(10 mins):
(Date:10/12/2017)... SAN DIEGO , Oct. 12, 2017   Divoti ... Medical Alert Jewelry up to the standard of the latest FDA ... (Launched: June 2017). Anyone in need of Medical ID ... Divoti Medical Alert Jewelry are engraved in terms of the ... ...
(Date:10/11/2017)... 2017  Caris Life Sciences ® , a leading ... of precision medicine, today announced that St. Jude Medical ... Alliance™ (POA) as its 17 th member. Through ... Crosson Cancer Institute will help develop standards of care ... profiling, making cancer treatment more precise and effective. ...
(Date:10/10/2017)... , Oct. 10, 2017  NDS received FDA 510(k) clearance ... a medical-grade battery-powered display stand specifically designed for endoscopy environments. An ... technology into a clinical solution to support the improvement of patient ... Innovative Design ... Wireless Solution ...
Breaking Medicine Technology: