PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Genetic alteration linked with human male infertility

2010-10-01
(Press-News.org) One in seven couples worldwide has difficulty conceiving a child, and male infertility is thought to account for nearly half of those cases. Although the cause of male infertility is often unknown, scientists have now discovered a genetic alteration that disrupts sperm production in otherwise healthy men. The research, published by Cell Press on September 30th in the American Journal of Human Genetics, provides new insight into one cause of male infertility.

"Many genes are known to be essential for the production of sperm, but there are surprisingly few single gene changes that have been conclusively demonstrated to cause a failure of sperm production in humans," explains senior study author, Dr. Ken McElreavey from the Pasteur Institute in France. Dr. McElreavey, along with co-authors Dr. Anu Bashamboo and Dr. John Achermann, a Wellcome Trust Senior Fellow from UCL Institute of Child Health London, examined whether the NR5A1 gene might be involved in some cases of male infertility.

The NR5A1 gene codes for a key protein called steroidogenic factor 1 that regulates fetal, prepubertal and adult sexual development. Previous work had shown that NR5A1 mutations are associated with severe defects in the development of the testes or ovaries as well as significant anomalies of the male external genitalia. Dr. McElreavey's group sequenced the NR5A1 gene in 315 healthy men seeking infertility treatment, who exhibited an unexplained failure to produce sperm.

"We identified seven men with severe failure to produce sperm who carried changes in the NR5A1 gene," says Dr. Bashamboo. The researchers went on to show that the mutations impaired the ability of the steroidogenic factor 1 protein to regulate the transcription of key reproductive genes. The mutations were associated with altered levels of sex hormones and, in the one case studied, mild abnormalities in the cellular structure of the testes. Similar genetic alterations were not observed in more than 2000 control samples.

These findings suggest that changes in NR5A1 are not just associated with severe and obvious defects in reproductive development. "We conclude the approximately 4% of men with otherwise unexplained failure to produce sperm carry mutations in the NR5A1 gene," says Dr. Bashamboo. "Our data also suggest that some forms of male infertility may be an indicator of a mild abnormality in testicular development, underlining a need for careful clinical investigation of men presenting with infertility and abnormal levels of sex hormones."

###

The researchers include: See PDF

END



ELSE PRESS RELEASES FROM THIS DATE:

Fossilized giant penguin reveals unusual colors, sheds light on bird evolution

2010-10-01
Paleontologists have unearthed the first extinct penguin with preserved evidence of scales and feathers. The 36-million-year-old fossil from Peru shows the new giant penguin's feathers were reddish brown and grey, distinct from the black tuxedoed look of living penguins. The new species, Inkayacu paracasensis, or Water King, was nearly five feet tall or about twice the size of an Emperor penguin, the largest living penguin today. "Before this fossil, we had no evidence about the feathers, colors and flipper shapes of ancient penguins. We had questions and this was ...

Researchers sequence genome of mosquito that spreads West Nile virus

Researchers sequence genome of mosquito that spreads West Nile virus
2010-10-01
RIVERSIDE, Calif. – Last year, 720 people in the United States became infected with West Nile virus, a potentially serious illness that is spread through the bite of a mosquito – the Culex mosquito – that has first fed on infected birds. Such mosquitoes have the virus eventually located in their salivary glands and transmit the disease to humans and animals when they bite to draw blood. To understand the genetic makeup of the Culex mosquito, and how the insect is able to transmit this and other viruses, an international team of scientists, led by geneticists at the ...

Researchers advance biosynthesis of potent anti-cancer drug Taxol

2010-10-01
MEDFORD/SOMERVILLE, Mass.--Researchers from Tufts University School of Engineering and MIT have reported a new way to biosynthesize important precursors to the potent anti-cancer compound Taxol in an engineered strain of E. coli bacteria. The findings are significant steps on the way to achieving cost-effective, large-scale production of Taxol and the effort to design new Taxol-like pharmaceuticals. The work is reported in the October 1, 2010, issue of the journal Science. Taxol (paclitaxel) and its structural analogs are among the most powerful and commercially ...

Researchers decode genome of mosquito that spreads West Nile virus, encephalitis and elephantiasis

2010-10-01
Chestnut Hill, Mass. (9/30/2010) – Scientists have sequenced the genome of the Southern house mosquito, providing new insights into the most diverse and widespread of three groups of disease-bearing mosquitoes and shedding new light on the transmission of mosquito-borne diseases such as malaria, encephalitis, West Nile virus and filariasis, international teams of researchers report in the upcoming edition of the journal Science. Breeding in drains, cesspools and other polluted water bodies, Culex quinquefasciatus feeds on blood from birds, livestock and humans and transmits ...

Ethnicity: A reason for heart problems post-transplant in South Asians

2010-10-01
Ethnicity is a contributing risk factor of cardiovascular problems in kidney recipients of South Asian origin post-transplant, according to a study appearing in an upcoming issue of the Clinical Journal of the American Society Nephrology (CJASN). South Asians comprise 25% of all Canadian visible minorities and have a higher risk for cardiovascular disease in the general population. However, the risk of cardiovascular events has never been studied in this minority population. To investigate, G.V. Ramesh Prasad, MBBS, MSc, FRCPC, FACP, FASN (University of Toronto) and ...

Fossilized giant penguin feathers reveal color, feather structure of ancient birds

2010-10-01
A North Carolina State University researcher is part of a team that has discovered fossilized feathers from a giant penguin that lived near the Equator more than 36 million years ago. These feathery fossils reveal color patterns in an ancient extinct penguin species, and offer clues to how modern penguin feathers evolved. The penguin in question – dubbed Inkayacu paracasensis, or Water King – dates from the late Eocene period and stood almost five feet tall. The fossil was discovered near the Paracas Reserve, located along the eastern coastline of Peru. A research team ...

Dinosaurs significantly taller than previously thought, MU researcher finds

Dinosaurs significantly taller than previously thought, MU researcher finds
2010-10-01
COLUMBIA, Mo.– It might seem obvious that a dinosaur's leg bone connects to the hip bone, but what came between the bones has been less obvious. Now, researchers at the University of Missouri and Ohio University have found that dinosaurs had thick layers of cartilage in their joints, which means they may have been considerably taller than previously thought. The study is being published this week in the journal PLoS ONE (Public Library of Science). "Our study of the limbs of modern-day relatives of dinosaurs shows that dinosaurs were significantly taller than original ...

Researchers engineer microbes for low-cost production of anti-cancer drug, Taxol

2010-10-01
CAMBRIDGE, Mass. -- MIT researchers and collaborators from Tufts University have now engineered E. coli bacteria to produce large quantities of a critical compound that is a precursor to the cancer drug Taxol, originally isolated from the bark of the Pacific yew tree. The tree's bacteria can produce 1,000 times more of the precursor, known as taxadiene, than any other engineered microbial strain. The technique, described in the Oct. 1 issue of Science, could bring down the manufacturing costs of Taxol and also help scientists discover potential new drugs for cancer and ...

Major disease-vector mosquito reveals the secrets of its immune system

2010-10-01
1st October 2010 - The Culex quinquefasciatus mosquito poses a significant threat to human health as a blood-sucking transmitter of elephantiasis-causing worms and encephalitis-inducing viruses. An international team of scientists, including researchers from the University of Geneva and the SIB Swiss Institute of Bioinformatics sequenced its genome and studied its responses to pathogen infections. Two articles published in today's issue of Science, describe results from comparing the Culex mosquito with the malaria mosquito, Anopheles gambiae, and the dengue mosquito, Aedes ...

Key nutrient found to prevent cataracts in salmon

Key nutrient found to prevent cataracts in salmon
2010-10-01
The role of a key nutrient which prevents cataracts in salmon has been revealed by eye specialists at the University of East Anglia. Research published today in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology shows how the nutrient histidine, when added to the diet of farmed salmon, stops cataracts (clouding of the lens in the eye) from forming. Following fears over BSE in the early 1990s, blood meal was removed from the diet of farmed salmon. This coincided with a large increase in the incidence of cataracts which cause economic ...

LAST 30 PRESS RELEASES:

Scientists agree chemicals can affect behavior, but industry workers more reluctant about safety testing

DNA nanospring measures cellular motor power

Elsevier Foundation and RIKEN launch “Envisioning Futures” report: paving the way for gender equity and women’s leadership in Japanese research

Researchers discover enlarged areas of the spinal cord in fish, previously found only in four-limbed vertebrates

Bipolar disorder heterogeneity decoded: transforming global psychiatric treatment approaches

Catching Alport syndrome through universal age-3 urine screening

Instructions help you remember something better than emotions or a good night’s sleep

Solar energy is now the world’s cheapest source of power, a Surrey study finds

Scientists reverse Alzheimer’s in mice using nanoparticles

‘Good’ gut bacteria boosts placenta for healthier pregnancy

USC team demonstrates first optical device based on “optical thermodynamics”

Microplastics found to change gut microbiome in first human-sample study

Artificially sweetened and sugary drinks are both associated with an increased risk of liver disease, study finds

Plastic in the soil, but not as we know it: Biodegradable microplastics rewire carbon storage in farm fields

Yeast proteins reveal the secrets of drought resistance

Psychiatry, primary care, and OB/GYN subspecialties hit hardest by physician attrition

New Canadian study reveals where HIV hides in different parts of the body

Lidocaine poisonings rise despite overall drop in local anesthetic toxicity

Politics follow you on the road

Scientists blaze new path to fighting viral diseases

The mouse eye as a window to spotting systemic disease

AI and the Future of Cancer Research and Cancer Care to headline October 24 gathering of global oncology leaders at the National Press Club: NFCR Global Summit to feature top scientists, entrepreneurs

FDA clears UCLA heart tissue regeneration drug AD-NP1 for clinical trials

Exploring the therapeutic potential of cannabidiol for Alzheimer's

We need a solar sail probe to detect space tornadoes earlier, more accurately, U-M researchers say

Acute myeloid leukemia (AML): Disease risk but not remission status determines transplant outcomes – new ASAP long-term results

Sperm microRNAs: Key regulators of the paternal transmission of exercise capacity

Seeing double: Clever images open doors for brain research

Inhaler-related greenhouse gas emissions in the US

UCLA Health study finds inhalers for asthma and COPD drive significant greenhouse gas emissions

[Press-News.org] Genetic alteration linked with human male infertility