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In and Out: steroid hormone and chromatin remodelling factors in female Drosophila GSC

November 4th, 2010 · Stem Cell

A latest article in Cell Stem Cell by Dr. Drummond-Barbosa Group in Vanderbilt University Medical Center, reports that the systemic factor ecdysone, a steroid hormone, and  ISWI / Nurf301 act together to regulate the female GSC self-renewal and proliferation independently of insulin signaling in Drosophila. It broadens our view of the mechanisms underlying GSC regulation from in and out with respect to systemic steroid hormone guidance and intrinsic epigenetic programming. – GeneDog

Cell Stem Cell. 2010 Nov 5;7(5):581-92.
The steroid hormone ecdysone functions with intrinsic chromatin remodeling factors to control female germline stem cells in Drosophila.

Ables ET, Drummond-Barbosa D.

Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA; Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; Division of Reproductive Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
Abstract

Steroid hormones are known systemic regulators of multiple normal and cancerous tissues; however, whether or how they impact the fate and function of adult stem cells is unclear. In the Drosophila ovary, insulin signals modulate the proliferation and self-renewal of germline stem cells (GSCs), yet despite evidence that additional systemic factors control GSC activity, these have remained largely unknown. Here, we report that ecdysone, a steroid hormone structurally related to mammalian sex steroids, directly regulates adult GSC proliferation and self-renewal independently of insulin signaling. Ecdysone controls GSCs through a functional interaction with the chromatin remodeling factors ISWI, an intrinsic epigenetic factor required for GSC fate and activity, and Nurf301, the largest subunit of the ISWI-containing NURF chromatin remodeling complex. Our findings support a link between systemic steroid hormones and the intrinsic chromatin remodeling machinery as a potential mechanism to promote broad transcriptional programs required for adult stem cell self-renewal.
Copyright © 2010 Elsevier Inc. All rights reserved.

PMID: 21040900

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Link between Germline Stem Cell Maintenance and Lifespan Extension by Dietary Restriction?

October 25th, 2010 · Stem Cell

It is well-known that lifespan is extended under dietary restriction (DR) to overcome the growth disadvantage. However, the underlying mechanisms remain largely unknown. A latest short article in Aging Cell reveals a potential link between lifespan and germline stem cell (GSC) in male Drosophila. – GeneDog

Aging Cell. 2010 Oct;9(5):916-8.
Dietary restriction enhances germline stem cell maintenance.

Mair W, McLeod CJ, Wang L, Jones DL.

The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
Abstract

Dietary restriction (DR) increases lifespan in species ranging from yeast to primates, maintaining tissues in a youthful state and delaying reproductive senescence. However, little is known about the mechanisms by which this occurs. Here we demonstrate that, concurrent with extending lifespan, DR attenuates the age-related decline in male germline stem cell (GSC) number in Drosophila. These data support a model whereby DR enhances maintenance of GSCs to extend the reproductive period of animals subjected to adverse nutritional conditions. This represents the first example of DR maintaining an adult stem cell pool and suggests a potential mechanism by which DR might delay aging in the tissues of higher organisms.
© 2010 The Authors Aging Cell © 2010 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

PMID: 20569233 [PubMed - in process]PMCID: PMC2944899 [Available on 2011/10/1]

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Scientific Journals in China: Quality or Quantity

October 12th, 2010 · Academic Publishing

A latest acticle from Nature News discussed the status of the China’s scientific journals published in Chinese language. The dilemma between journal quantity and quality may be resolved by the switch of the journals from Chinse language to English to compete on an international scale, and finally, to enhance the journal reputation and receive broader audience. – GeneDog

Weak publications will be ‘terminated’.

by David Cyranoski

Few Chinese scientists would be surprised to hear that many of the country’s scientific journals are filled with incremental work, read by virtually no one and riddled with plagiarism. But the Chinese government’s solution to this problem came as a surprise last week.

Li Dongdong, a vice-minister of state and deputy director of the General Administration of Press and Publications (GAPP) — the powerful government body that regulates all publications in China — acknowledged that the country’s scientific publishing had a “severe” problem, with “a big gap between quality and quantity”, and needed reform.

Opening a meeting of scientific publishers in Shanghai on 7 September, Li announced that by January 2011, new regulations will be used to “terminate” weak journals.

Precisely how this reform will work is the subject of hot debate. If an evaluation process finds a journal to be weak, it may be forced to close altogether, or relaunch with a different editorial board, a different title or even a different subject focus.

Those journals judged to be strong will receive support such as tax breaks. Scientific publishing will be concentrated in “five-to-ten large publishing groups” that will compete with each other, says Li. “We will turn China from a large science and technology publisher to a powerful science and technology publisher.” GAPP did not respond to Nature ’s requests for more information.

News of the regulation startled many of the publishers at last week’s meeting, the 6th China Science Journal Development Forum. Some believe that bureaucrats should not be interfering with journals, and others say that powerful scientists will resist the move. But all agreed that China’s scientific publishing is in bad shape.

Approximately one-third of the roughly 5,000 predominantly Chinese-language journals are ‘campus journals’, existing only so that graduate students and professors can accumulate the publications necessary for career advancement, according to one senior publisher. And in a Correspondence to Nature last week, Yuehong Zhang of the Journal of Zhejiang University–Science reported that a staggering 31% of the papers submitted to that campus journal contained plagiarized material ( Nature 467, 153; 2010).

Most Chinese journals make their money through funding from their host institutions, and by charging authors per-page publishing fees. “Most are never cited. Who knows if they’re even really published. They’re ghosts,” says one publisher, who declined to be named. Wu Haiyun, a cardiologist at the Chinese PLA General Hospital in Beijing, says that only 5–10% of these journals are worth saving, and the rest are “information pollution”.

Most of China’s top researchers already forgo Chinese publications for international ones, where they earn the recognition that can promote their career. And they are increasingly successful: in November 2009, scientists from China became the second-most prolific publishers of scientific articles in international scientific journals.

But some Chinese librarians are beginning to baulk at the prices charged by these foreign journals. On 1 September, an open letter signed by 35 librarians criticized foreign science, technology and medicine publishers for “using their monopolistic position” to raise subscription prices annually by more than 14% for the next 3 years. Meanwhile, some of the better Chinese journals are being published in collaboration with foreign companies such as Wiley–Blackwell and Springer, respectively headquartered in Hoboken, New Jersey, and Berlin. Cell Research, for example, based at the Shanghai Institutes for Biological Sciences and co-published by Nature Publishing Group, reached an impact factor of 8.2 in 2009 — the highest in the Asia-Pacific region, including Australia.

Impact factors could provide an important cornerstone of the government’s evaluation system. For example, the Chinese Journal Citation Report, published by the Institute of Scientific and Technical Information of China since 2004 and covering some 1,800 of China’s top journals, provides impact factors that measure their significance on the basis of the number of times that articles are cited by peers.

Many Chinese journals are switching to publishing in English to increase their impact factors, and more than 200 English-language science and technology journals are now based in China. ACTA Genetica Sinica became the Journal of Genetics and Genomics in 2007; Neuroscience Bulletin, founded in 1998, switched to English in 2006; and in January 2009, Acta Zoologica Sinica, published since 1935 and the second-oldest journal in China, became Current Zoology. In its first year, the proportion of papers that it published from non-Chinese scientists shot up from 16% to 42%. Having earned a spot on the list of journals counted by Thomson Reuters Web of Knowledge, the journal is awaiting its first impact factor. Martin Stevens, a zoologist at the University of Cambridge, UK, says that Current Zoology is now finding a niche. “Before, there weren’t any journals that had this relatively broad audience. Many looked at specific areas of biology,” says Stevens, who guest edited a special issue of the journal about how the sensory system relates to evolution.

A minority of Chinese scientists argue that there is no need for Chinese-language primary research journals at all. All original Chinese research should be published in English-language journals to get the widest audience possible, says Wu, who adds that Chinese-language journals should stick to publishing continuing education and review articles. “Is it necessary for China to have its own journals?” he asks.

The government’s answer is an emphatic ‘yes’. For Li, strong scientific publishing is a necessary “driving force in innovation and technological strength”. Once the new reforms are under way, she says, “journals will be a strong part of our soft power”.

via http://www.nature.com/news/2010/100915/full/467261a.html

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Rocket-jumping of Cell Research Impact Factor

June 18th, 2010 · Academic Publishing

Today, the latest Imfact Factor for scientific journals has been released out by Thomson Reuters’s JCR report. As China’s leading journal in the life sciences, Cell Research harvested its credit 8.151. A Rocket-jumping from  around 5.

Cell Research is run by Institute of Biochemistry and Cell Biology in China, Dr. Dangsheng Li as chief editor, previous Associate Editor of Cell.

As mentioned in one previous post, Dr. Li also started another peer-reviewed journal Journal of Molecular Cell Biology (JMCB) last year. Definitely, Cell Research and “the new launch of JMCB will greatly promote the communications and exchanges of big-bang-ideas between Chinese and international biological scientists.”

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PLoS ONE Impact Factor Estimating

June 2nd, 2010 · Academic Publishing

After the open access journal PLoS ONE being indexed by Web of Science at the begin of 2010, PLoS ONE will harvest a full report of citation metrics from 2009 Journal Citation Reports®, although PLoS Says NO to journal impact factor and “focus efforts on more sophisticated, flexible and meaningful measures”.

Nevertheless, its journal impact factor will be available in June 2010.

The rough estimate of PLoS ONE impact factor is 5-7. Wait and See!

UPDATED:

Finally, the latest impact factor for PLoS One is released out with 4.351, a bit far from the earlier estimate.

Cheers!

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JCR ISI Journal Impact Factor 2010 Coming

June 2nd, 2010 · Academic Publishing

The latest JCR ISI Journal Impact Factor 2010 (actually the Impact Factor 2009) is coming during June.

The journal Impact Factor 2010 is based on the previous two-year average citations per published research paper.

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PcG genes restrict Drosophila follicle stem cell (FSC) growth

May 9th, 2010 · Stem Cell

A latest research paper in Genes Dev. by the NIBS group of Dr. Xi RW from China:

Genes Dev. 2010 May;24(9):933-46.
Polycomb group genes Psc and Su(z)2 restrict follicle stem cell self-renewal and extrusion by controlling canonical and noncanonical Wnt signaling.

Li X, Han Y, Xi R.

National Institute of Biological Sciences, Beijing 102206, People’s Republic of China.
Abstract

Stem cells are critical for maintaining tissue homeostasis and are commonly governed by their niche microenvironment, although the intrinsic mechanisms controlling their multipotency are poorly understood. Polycomb group (PcG) genes are epigenetic silencers, and have emerged recently as important players in maintaining stem cell multipotency by preventing the initiation of differentiation programs. Here we describe an unexpected role of specific PcG genes in allowing adult stem cell differentiation and preventing stem cell-derived tumor development. We show that Posterior sex combs (Psc), which encodes a core Polycomb-repressive complex 1 (PRC1) component, functions redundantly with a similar gene, Suppressor of zeste two [Su(z)2], to restrict follicle stem cell (FSC) self-renewal in the Drosophila ovary. FSCs carrying deletion mutations of both genes extrude basally from the epithelium and continue to self-propagate at ectopic sites, leading to the development of FSC-like tumors. Furthermore, we show that the propagation of the mutant cells is driven by sustained activation of the canonical Wnt signaling pathway, which is essential for FSC self-renewal, whereas the epithelial extrusion is mediated through the planar cell polarity pathway. This study reveals a novel mechanism of epithelial extrusion, and indicates a novel role of polycomb function in allowing adult stem cell differentiation by antagonizing self-renewal programs. Given evolutionary conservation of PcG genes from Drosophila to mammals, they could have similar functions in mammalian stem cells and cancer.

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PubAlert: Stay Alerted to Latest Research Publications for Free

March 29th, 2010 · Academic Publishing

PubAlert is initially produced for my convenience, mainly covering journals in the developmental biology field. Still it’s publicly accessible, for you!

What’s PubAlert all about?

PubAlert ( http://pub.genedog.org/ )is a free and non-profit online aggregator service that functions to track the scientific journals and bring together the up-to-date research articles all into one channel. So you can stay alerted to new research publications by visiting PubAlert on a regular basis.

Check it out!

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How To Check The Impact Factor of your Favorite Scientific Journals

March 16th, 2010 · Academic Publishing

There are some readers asking, “How do I find the impact factor for a journal?”…hmmm…Before answering this issue, you should be noticed that, this blog DONOT distribute the impact factor list in any format (pdf, excel/xls, word/doc, etc).

However, you can check information on impact factor of your favorite scientific journals in the following ways:

  1. Check ISI Web of Knowledge with a new session if necessary at http://admin-apps.isiknowledge.com/JCR/JCR to get the up-to-date sci impact factor scores of 2008/2009 journal ranking performance.
  2. Google it! Generally, you can get the necessary impact factor information at the official website of the corresponding journals!

Check it out by yourself~ :)

2010.03.16

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Cochlear implant offers you the hope of regaining hearing

February 14th, 2010 · Product Review

As we all know, loss in the ability to hear or discriminate sounds clearly is a common disability, which will cause the patients to be depressed and suffer from the quality of life. If temporarily there is no cure for the hearing loss, hearing aids may help to improve your hearing. Cochlear implant, an electronic device created utilizing the advances in techonogy,  is such a solution of hearing aid for children and adults who have hearing problems.

[Read more →]

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