Navigation Links
Variation in women's X chromosomes may explain differences among individuals, between sexes

.

Originally, scientists had assumed that the inactivation process resulted in complete silencing of the genes on the second X chromosome, Willard said, in order to leave both sexes with the same activity level, or dosage, of the genes encoded by the X chromosome. Scientists had also implicitly assumed that the X chromosomes in all women would be identical.

Earlier work of Willard and others shattered the first assumption, when, in the late 1980s, the first evidence came to light that some portion of the genes on the second X chromosome in women remained active.

The new work extends that earlier finding to the full set of X-linked genes and also further reveals that individual women exhibit extensive differences among them with respect to X inactivation, Willard said.

In their study, the researchers isolated cell lines from each of 40 women. They then measured the activity level of each of 471 genes to determine whether the second copy was turned on or off.

Overall, about 15 percent of genes on the second X chromosome escape inactivation to some degree, they found. The proportion of genes that remain active differs dramatically among regions of the X chromosome, they reported.

Furthermore, in some women but not others, an additional 10 percent of X-linked genes demonstrate variable patterns of inactivation and different levels of activity in the "silenced" X chromosomes, the team reported.

"The findings suggest a remarkable and previously unsuspected degree of expression heterogeneity among females in the population," Willard said. Further work is required to explore potential consequences of that variation, he added.

However, the large number of genes that escape inactivation and their concentration in certain portions of the X chromosome has immediate implications for counseling the one in every 650 individuals born with X chromosome abnormalities, Willard said. The expected severity of symptoms assoc
'"/>

Source:Duke University Medical Center


Page: 1 2 3

Related biology news :

1. Genetic Variation Visualization - From EMBL
2. Variation in HIVs ability to disable host defenses contributes to rapid evolution
3. Variation in bitter-taste receptor gene increases risk for alcoholism
4. Variations in detoxifying genes linked to Lou Gehrigs disease
5. Of mice and mens (and womens) contraceptives
6. Heavy smoking cuts womens chance of pregnancy -- even with donated oocytes
7. Scientists analyze chromosomes 2 and 4
8. Mouse to man: The story of chromosomes
9. Researchers use multiphoton microscopy to watch chromosomes in action
10. Short chromosomes put cancer cells in forced rest
11. Researchers attach genes to minichromosomes in maize
Post Your Comments:
(Date:4/1/2015)... --  Medisafe ™, the leading global medication management platform ... and Android smartphones and tablets, announces today ... to allow patients to track and correlate their adherence ... will be able to visualize in real-time how taking ... as glucose levels and blood pressure. "Patients ...
(Date:3/31/2015)... YORK , March 31, 2015   Guidepoint ... the launch of the Post-Surgical Pain Management TRACKER, part ... products tracking usage trends in the medical device and ... access to data including treatment volumes, market share, and ... the pain associated with joint surgery. The ...
(Date:3/26/2015)... 26, 2015 The Granite Club, ... and athletic club, today announced it has implemented a ... of movement for members and staff, while restricting access ... process, we selected FST,s IMID Access system because it ... our members and staff, in addition to unparalleled security," ...
Breaking Biology News(10 mins):Medisafe Announces Launch of Biometric Integration, Enabling Patients to Stay Adherent to Their Meds and See Tangible Health Results 2Guidepoint Launches Post-Surgical Pain Management TRACKER 2Guidepoint Launches Post-Surgical Pain Management TRACKER 3Granite Club First Private Club in North America to Implement FST Biometrics Secure Access Solution, as Part of Multi-million Dollar Expansion 2
... The northern spotted owl, a threatened species in the ... from active management of the forest lands that form ... fire, researchers conclude in a recent study. Whatever ... other fuel reduction activities in areas with high fire ...
... scientific community has always wanted to know why people ... problems such as kidney stones and osteoporosis. , Medical ... this puzzle through their work with animal lab models ... recently discovered an important link between sodium and calcium. ...
... -- The San Francisco State University researchers who accidentally ... want people across the United States and Canada to ... Today SF State Professor of Biology John Hafernik and ... the Center for Computing for the Life Sciences launched ...
Cached Biology News:Active forest management to reduce fire could help protect northern spotted owl 2Diets high in salt could deplete calcium in the body: UAlberta research 2Citizen scientists needed for SF State's 'ZomBee Watch' 2
(Date:4/16/2015)... Morton Grove, IL (PRWEB) April 16, 2015 ... the American Association for Cancer Research (AACR) ... at the Pennsylvania Convention Center, starting Saturday, April 18, ... The AACR holds claim to title of the oldest ... several journals, provides fellowships and grants, and partners with ...
(Date:4/16/2015)... -- In recognition of World Hemophilia Day, Biogen  (NASDAQ: ... more than 15 prominent landmarks red throughout the ... Zakim Bridge and Prudential Tower, Chicago,s ... and Denver,s Coors Field . ... and coincide with hemophilia community events in a dozen locations ...
(Date:4/16/2015)... ChemRar High Tech ... R&D group, and Lancet, Russian Distribution Company, ... commercialization of new medicines in ... stimulate the innovative development of the Russian ... ,     (Logo: http://photos.prnewswire.com/prnh/20150416/739742-b) , Through ...
(Date:4/16/2015)... -- Avelas Biosciences, an in vivo cancer ... that it has initiated a Phase 1b study of ... primary, non-recurrent breast cancer undergoing surgery. In commencing the ... Steven Chen , M.D., as vice president of ... study will enroll up to 39 women with stage ...
Breaking Biology Technology:Regis Technologies Joins American Association for Cancer Research Annual Meeting 2Biogen Shines A Light On Hemophilia Community By Illuminating U.S. Landmarks Red On World Hemophlia Day 2Biogen Shines A Light On Hemophilia Community By Illuminating U.S. Landmarks Red On World Hemophlia Day 3Biogen Shines A Light On Hemophilia Community By Illuminating U.S. Landmarks Red On World Hemophlia Day 4Lancet and ChemRar High Tech Center Have Announced a Partnership in the Development and Production of Novel Drugs in Russia 2Avelas Biosciences Initiates Phase 1b Trial of AVB-620 in Breast Cancer Patients 2Avelas Biosciences Initiates Phase 1b Trial of AVB-620 in Breast Cancer Patients 3
... real environment, the city of Madison. Image courtesy of ... Firefighters need to be fully prepared, practicing hundreds of ... to respond to a chemical spill immediately, getting the ... to work together, planning the best strategy to avoid ...
... ago, a mega-merger of higher education institutions created the University ... insist those who pine for days gone by, but the ... Wisconsins public resources. , ,The time has come for ... time with 21st century realities in mind. Facing a state ...
... announcement that it plans to buy its former parent ... for new opportunities. , ,Drew Petersen, director of legislative affairs ... and AT&T is a sign that SBC plans to become ... TDS, which Petersen said tries to present itself as a ...
Cached Biology Technology:How games have evolved to provide real-world education 2How games have evolved to provide real-world education 3How games have evolved to provide real-world education 4Structural change is coming to the UW System 2Structural change is coming to the UW System 3SBC merger with AT&T could open opportunities in Wisconsin 2