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:7/30/2014)... climate change on the world,s animal and plant ... to a new paper by a research team ... and other organizations. The authors claim that most ... when it comes to climate change. , ... on the "direct" threats of changing temperatures and ...
(Date:7/30/2014)... Society of America (ESA) has elected ten new Fellows ... Fellow acknowledges outstanding contributions to entomology in one or ... The following Fellows will be recognized during Entomology 2014 ... held November 16-19, 2014 in Portland, Oregon. , ... the Department of Plant, Soil and Entomological Sciences at ...
(Date:7/30/2014)... joint venture between The University of Texas at San ... Center at San Antonio, has selected the winners of ... from UTSA and Lei Huang from the Health Science ... engineered ferritins for tracking and protecting neural stem cells ... focused on finding a treatment for stroke through stem ...
Breaking Biology News(10 mins):Conservation scientists asking wrong questions on climate change impacts on wildlife 2Entomological Society of America recognizes 2014 fellows 2Entomological Society of America recognizes 2014 fellows 3Entomological Society of America recognizes 2014 fellows 4Entomological Society of America recognizes 2014 fellows 5Entomological Society of America recognizes 2014 fellows 6Entomological Society of America recognizes 2014 fellows 7Entomological Society of America recognizes 2014 fellows 8Entomological Society of America recognizes 2014 fellows 9Entomological Society of America recognizes 2014 fellows 10Entomological Society of America recognizes 2014 fellows 11Entomological Society of America recognizes 2014 fellows 12Entomological Society of America recognizes 2014 fellows 13Entomological Society of America recognizes 2014 fellows 14Entomological Society of America recognizes 2014 fellows 15Entomological Society of America recognizes 2014 fellows 16Entomological Society of America recognizes 2014 fellows 17
... people around the world, causing numerous problems ranging from ... Initial drug use can be motivated by curiosity or ... it can also be the result of a stressful ... study examines the impact of social isolation on the ...
... who studied a little genetics in high school has heard ... C that make up the DNA code. But those are ... past decade has drawn attention to a fifth nucleotide, 5-methylcytosine ... helix to regulate which genes are expressed. And now there,s ...
... time. Travelers in search of answers. It sounds ... it also describes a new approach to teaching earth ... associate professor of geology at Kansas State University, and ... of Missouri at Kansas City, designed TerraWorld, an island ...
Cached Biology News:Early isolation linked to enhanced response to cocaine 2New nucleotide could revolutionize epigenetics 2New nucleotide could revolutionize epigenetics 3New nucleotide could revolutionize epigenetics 4K-State using Second Life island to help high school students learn earth science 2
(Date:7/31/2014)... the sound-processing part of the mouse brain in a ... trees in view. Their imaging technique allows zooming in ... and it enabled the team to watch brain cells ... results, which represent a step toward better understanding how ... the journal Neuron . , In the past, ...
(Date:7/31/2014)... VALLEY, Calif. , July 31, 2014 ... San Francisco Bay Area , has acquired ... University of Oxford,s commercialisation company. The potent anti-inflammatory activity ... Greaves at the University of Oxford,s Sir ... The company, which has raised over $1.5 million in ...
(Date:7/31/2014)... -- Research and Markets has announced the ... report to their offering. ... the genetic material or genomes of an organism. It ... discovery and development of diagnostic and therapeutic solutions for ... is supported by three major product segments: Instruments, Consumables, ...
(Date:7/31/2014)... SAN DIEGO and SHENZHEN, China ... Genomics announced today the purchase of an ... genomics organization. BGI selected BioNano,s platform to enable comprehensive ... vastly improved assemblies for various organisms of interest, including ... BGI will partner together to develop new methods for ...
Breaking Biology Technology:New mapping approach lets scientists zoom in and out as the brain processes sound 2Oxford licenses anti-inflammatory peptides to San Francisco Bay Area start-up 2Oxford licenses anti-inflammatory peptides to San Francisco Bay Area start-up 3Global Genomics Market 2014-2018: Key Vendors are F. Hoffmann-La Roche, Life Technologies, Qiagen and Illumina 2BioNano Genomics Announces the Purchase of the Irys System by BGI 2BioNano Genomics Announces the Purchase of the Irys System by BGI 3BioNano Genomics Announces the Purchase of the Irys System by BGI 4
... Accelerate Customer Development Programs; Agreement Underscores SAFC,s Commitment to Japan ... April 28 SAFC Hitech (R), a ... (Nasdaq: SIAL ), today underlined its commitment to ... partnership with leading industrial and medical gas producer, ...
... Phase 1 healthy volunteer study of IMX942 will provide ... 28 /PRNewswire/ - Inimex Pharmaceuticals is pleased to announce ... administered to human subjects for the first time on ... a Phase 1 safety study of IMX942 being performed ...
... pain palliation as an acceptable primary endpoint, ... approval,BOTHELL, WA, April 28 /PRNewswire-FirstCall/ - OncoGenex Pharmaceuticals, Inc. ... company has reached an agreement with the U.S. Food ... second Phase 3 registration trial of OGX-011, its lead ...
Cached Biology Technology:SAFC Hitech & Air Water Inc. Extend High-End Materials Research Services Collaboration to Support Japan Chip Industry 2SAFC Hitech & Air Water Inc. Extend High-End Materials Research Services Collaboration to Support Japan Chip Industry 3SAFC Hitech & Air Water Inc. Extend High-End Materials Research Services Collaboration to Support Japan Chip Industry 4SAFC Hitech & Air Water Inc. Extend High-End Materials Research Services Collaboration to Support Japan Chip Industry 5Inimex Pharmaceuticals begins First Clinical Study of an Innate Defense Regulator 2OncoGenex Receives Confirmation from FDA on the Design of a Second Phase 3 Trial Evaluating OGX-011 for the Treatment of Advanced Prostate Cancer 2OncoGenex Receives Confirmation from FDA on the Design of a Second Phase 3 Trial Evaluating OGX-011 for the Treatment of Advanced Prostate Cancer 3OncoGenex Receives Confirmation from FDA on the Design of a Second Phase 3 Trial Evaluating OGX-011 for the Treatment of Advanced Prostate Cancer 4OncoGenex Receives Confirmation from FDA on the Design of a Second Phase 3 Trial Evaluating OGX-011 for the Treatment of Advanced Prostate Cancer 5OncoGenex Receives Confirmation from FDA on the Design of a Second Phase 3 Trial Evaluating OGX-011 for the Treatment of Advanced Prostate Cancer 6
... ProteinChip arrays have been developed for ... samples. A variety of ProteinChip chemical ... according to their unique biochemical properties. ... allowing side-by-side sample comparison, and the ...
The Freeze 'N Squeeze DNA gel extraction kit uses a quick freeze-and-thaw cycle and centrifugation to draw 50-23,000 bp DNA out of agarose gel slices. The kit includes materials for 100 preps....
The thermal printer, 120 V, is used to record fluorescence data acquired with the VersaFluor fluorometry systems. The printer includes a cable and power adaptor....
The Sony UPD895 printer is used to print data captured with the Gel Doc XR and ChemiDoc XRS gel documentation systems as well as the VersaDoc imaging systems....
Biology Products: