Navigation Links
The story of X -- evolution of a sex chromosome
Date:4/16/2009

that probably took place about 150 million years ago, while in the fruit fly Drosophila melanogaster, a laboratory favorite, the sex chromosomes arose independently about 100 million years ago. In both humans and fruit flies, the Y chromosome has dwindled from a few thousand genes to a few dozen.

Hence the intense interest in why and how the Y chromosome lost genes once it stopped interacting with the X. Scientists have found that, as the only chromosome pair that doesn't break and recombine every time a cell divides, the XY pair in males is unable to take advantage of the main way deleterious genetic mutations are eliminated. The XX pair in females does recombine, but for the Y, the only way to get rid of a bad mutation in a gene is to inactivate or delete the entire gene. Over millions of years, inactive genes are lost, and the Y shrinks.

"If you have no recombination, natural selection is less effective at removing detrimental genes," said Bachtrog. "Y is an asexual chromosome, and it pays a price for that: It keeps losing genes."

Bachtrog, whose career has revolved mostly around the study of the degeneration of the Y chromosome, decided to focus on the X chromosome several years ago and went about searching for sex chromosome pairs that have arisen more recently and thus might be in the process of adapting to their new role. Her paper centers around study of the three sex chromosomes in a rare western fruit fly, Drosophila miranda, a darker-colored cousin of D. melanogaster. (Many creatures have more than one pair of sex chromosomes; the platypus, for example, has five pairs, all inherited together.)

While one of D. miranda's sex chromosomes is descended from the original sex chromosome that appeared in Drosophila nearly 100 million years ago, a second originated perhaps 10 million years ago, and the third about a million years ago. The older two look much alike, Bachtrog said: The Y chromosome in each pair has lost genes to
'/>"/>

Contact: Robert Sanders
rsanders@berkeley.edu
510-643-6998
University of California - Berkeley
Source:Eurekalert

Page: 1 2 3 4

Related biology news :

1. Story ideas from the Journal of Lipid Research
2. Story tips from the US Department of Energys Oak Ridge National Laboratory, September 2007
3. Satellites witness lowest Arctic ice coverage in history
4. Census of protein architectures offers new view of history of life
5. New study sheds light on Galápagos hawk evolutionary history
6. Microfossils disclose geologic history of eastern California
7. Story ideas from Molecular & Cellular Proteomics
8. Story tips from the Department of Energys Oak Ridge National Laboratory, October 2007
9. Story ideas from the Journal of Biological Chemistry
10. Rebuilding the evolutionary history of HIV-1 unravels a complex loop
11. Nanotechnology and the media: The inside story
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/8/2015)... -- Synaptics Inc. (NASDAQ: SYNA ), the leading developer ... executive management team will present at the following investor events: ... Conference Date: May 18, 2015 Time: 10:40am ET ... Cowen and Company Technology, Media & Telecom ... New York Palace Hotel, New York, NY ...
(Date:5/5/2015)... NXT-ID, Inc. (NASDAQ: NXTD ) ("NXT-ID" or ... mobile commerce market, reminds investors and media that  Mr. ...  at CARTES SECURE CONNEXIONS AMERICA 2015, held in ... The three-day conference is organized into a series of nine ... Global Fraud: Where is the Trust in Cyberspace? ...
(Date:4/27/2015)... LAUDERDALE, Fla. , Apr. 27, 2015 ... of access control and security systems is pleased to ... the company as a consultant and member of its ... is widely known as a thought leader in ... Distance Learning Technology Group, and has published studies and ...
Breaking Biology News(10 mins):Synaptics to Present at Upcoming Investor Conferences 2NXT-ID, Inc.'s CTO, David Tunnell, Presents at CARTES SECURE CONNEXIONS AMERICA 2015 Today in Washington DC. 2NXT-ID, Inc.'s CTO, David Tunnell, Presents at CARTES SECURE CONNEXIONS AMERICA 2015 Today in Washington DC. 3Profile Solutions Names Medicinal Cannabis, Agriculture and Technology Expert Dr. Gerry Bedore to its Scientific Advisory Board 2Profile Solutions Names Medicinal Cannabis, Agriculture and Technology Expert Dr. Gerry Bedore to its Scientific Advisory Board 3Profile Solutions Names Medicinal Cannabis, Agriculture and Technology Expert Dr. Gerry Bedore to its Scientific Advisory Board 4
... SALT LAKE CITYResearchers have discovered two enzymes that, when ... cancer. Manipulating these enzymes genetically might lead to targeted ... tumors. "We could conceivably reactivate a completely normal ... could prevent the growth of a tumor if reactivated," ...
... crimefighter who protected the innocent from pirates, hijackers and ... its costumed namesake, this electromagnetic phantoma carbon and polymer ... the National Institute of Standards and Technology (NIST) for ... The NIST phantom serves as a mannequin in a ...
... Researchers at The University of Texas School of Public Health ... of community-acquired antibiotic-resistant Staph ylococcus aureus ... (PVL). The Panton Valentine leukocidin is made ... is typically produced by community-acquired methicillin-resistant S. aureus ...
Cached Biology News:Newly found enzymes may play early role in cancer 2Electromagnetic phantom exorcises specters of metal detector tests 2UT Public Health researchers find link to severe Staph infections 2
(Date:6/1/2015)... BAY HEAD, N.J. , June 1, 2015 /PRNewswire/ ... to launch a national innovative science curriculum for high ... announcement at the 16 th annual LIFE Event ... held at Mountain Ridge Country Club in ... some of the LPGA,s biggest stars raised more than ...
(Date:6/1/2015)... N.C. , June 1, 2015  Fennec ... presentation of positive interim results from a poster ... multi-centre open label randomised phase III trial of ... ototoxicity in patients receiving cisplatin (Cis) monotherapy for ... at the American Society of Clinical Oncology (ASCO) ...
(Date:6/1/2015)... and SOUTH SAN FRANCISCO, Calif. ... the venture arm of Baxter International Inc. (NYSE: ... LLC ("VPD") today announced the formation of Vitesse Biologics, ... by Baxter Ventures to focus on the development of ... hematology, and oncology. Following the spin-off of Baxter BioScience ...
(Date:6/1/2015)... June 1, 2015 Esperance Pharmaceuticals Inc. today ... lead candidate EP-100 in ovarian cancer patients resistant to ... seek and destroy cancer cells that overexpress luteinizing hormone-releasing ... over-expressed in a wide range of cancers. ... trial of EP-100 were presented at the 2015 ...
Breaking Biology Technology:Val Skinner Foundation Announces Partnership With Discovery Education 2Fennec Announces Presentation Of Positive Interim Sodium Thiosulfate Phase III Safety Data At The 2015 ASCO Annual Meeting 2Fennec Announces Presentation Of Positive Interim Sodium Thiosulfate Phase III Safety Data At The 2015 ASCO Annual Meeting 3Fennec Announces Presentation Of Positive Interim Sodium Thiosulfate Phase III Safety Data At The 2015 ASCO Annual Meeting 4Baxter Ventures, Mayo Clinic And Velocity Pharmaceutical Development Announce The Formation Of Vitesse Biologics, LLC, A Company Structured To Accelerate Therapeutic Innovation 2Baxter Ventures, Mayo Clinic And Velocity Pharmaceutical Development Announce The Formation Of Vitesse Biologics, LLC, A Company Structured To Accelerate Therapeutic Innovation 3Baxter Ventures, Mayo Clinic And Velocity Pharmaceutical Development Announce The Formation Of Vitesse Biologics, LLC, A Company Structured To Accelerate Therapeutic Innovation 4Baxter Ventures, Mayo Clinic And Velocity Pharmaceutical Development Announce The Formation Of Vitesse Biologics, LLC, A Company Structured To Accelerate Therapeutic Innovation 5Esperance Reports Positive EP-100 Phase ll Results in Ovarian Cancer at 2015 ASCO Annual Meeting 2Esperance Reports Positive EP-100 Phase ll Results in Ovarian Cancer at 2015 ASCO Annual Meeting 3
... Platypus Technologies of suburban Madison has received ... for $200,000 from the National Cancer Institute. The grant ... rapid quantification of protein activity, useful for cancer research. ... II SBIR grant for $2.14 million from the National ...
... been calls to run government institutions as a business, ... their shareholders: taxpayers. Now schools are facing similar scrutiny. ... Behind Act have expanded the federal regulations with which ... are also demanding more budget accountability at a time ...
... Inc ., a provider information management systems and services ... a definitive agreement to acquire BillMatrix Corp ., ... , ,BillMatrix, founded in 1994, provides billers with an ... immediate credit for bills paid online or over the ...
Cached Biology Technology:Looking to software to manage the business of education 2Looking to software to manage the business of education 3Looking to software to manage the business of education 4
... 2500ml narrow mouth PYREX low form culture flask is ... to volume ratio. This flask has a heavy beaded ... marking spot. The neck O.D. is 38mm and takes ... use this flask on a heat source smaller than ...
... The loxP-amp-loxP cassette is ... cells. The prokaryotic promoter gb2 driving ... slightly modified version of the Em7 promoter. ... generally used Tn5 promoter. A synthetic polyadenylation ...
... is designed to allow ampicillin selection in ... driving the gene for ampicillin resistance is ... promoter. It mediates higher transcription efficiency than ... polyadenylation signal terminates the ampicillin expression. The ...
... for the fast and simple integration of ... position (for the generation of transgenic mouse ... to allow neomycin / kanamycin selection in ... prokaryotic promoter (gb2) for expression of kanamycin ...
Biology Products: