Telomeres at the end of chromosomes shorten during aging

Genes reveal 'biological ageing'

Gene variants that might show how fast people's bodies are actually ageing have been pinpointed by scientists.

Researchers from the University of Leicester and Kings College London say the finding could help spot people at higher risk of age-related illnesses.

People carrying the variant had differences in the "biological clock" within all their cells.

The British Heart Foundation said the findings could offer a clue to ways of preventing heart disease.

While doctors know that as people age they are more at risk from diseases such as Alzheimer's, Parkinson's and heart disease, some people fall prey to these at an earlier age than expected.

Telomeres

One theory suggests that biological timers called "telomeres", part of the chromosomes in every cell that carry genetic code, may be a factor in this.

From birth, every time a cell divides, the telomeres get shorter and there is some evidence that people with shorter telomeres, either because they diminish more quickly or because they were born with shorter versions, may be at higher risk from age-related illness.

The researchers say in the journal, Nature Genetics, that they looked at more than 500,000 genetic variations across the entire human genome to see which variants cropped up more frequently in people known to have shorter telomeres.

They eventually located a number of variants located near a gene called TERC which, in people carrying them, seemed to be equivalent to an extra three or four years of "biological ageing".

Bad lifestyles

Professor Tim Spector, from King's College London, said: "What our study suggests is that some people are genetically programmed to age at a faster rate.

"Alternatively, genetically susceptible people may age even faster when exposed to proven 'bad' environments for telomeres such as smoking, obesity or lack of exercise - and end up several years biologically older or succumbing to more age-related diseases."

Professor Jeremy Pearson, associate medical director at the British Heart Foundation, which part-funded the study, said it was not yet clear whether telomeres did contribute to an increased risk of disease.

He said: "Understanding how our cells age is an important step in our quest for better ways to prevent and treat heart disease.

"Perhaps in the future one of the ways we try to reduce the risk of, or treat, heart disease would be to use an 'anti-ageing' approach for our arteries."

Smoking causes genetic damage in minutes, rather than months

A recent study found that certain substances in tobacco can cause genetic damage within a few minutes -- rather than months, according to media reports Wednesday.

The long term impact of smoking, from heart disease to a range of cancers, is well known.

This study suggests the damage begins just moments after the first cigarette is smoked.

The study shows that the DNA damage associated with lung and other types of cancer become apparent within 15-30 minutes of inhaling cigarette smoke. It is a time frame that surprise even the researchers.

Smoking is to blame for about 90 percent of lung cancers and is linked to at least 18 other types of cancer.

Lung cancer claims 3,000 lives worldwide each day, mostly as a result of cigarette smoking.

Anti-smoking charity Ash described the research as "chilling" and as a warning that it is never too early to quit.

Int'l study finds new genetic loci associated with menopause onset

WASHINGTON, Jan. 23 -- An international team of researchers from the Boston University and other institutions has uncovered 13 genetic loci, linked to immune function and DNA repair, that are factors in the age of onset of menopause.

Menopause -- the cessation of reproductive function of the ovaries -- is a major hormonal change that affects most women when they are in their early 50s. Most prior studies of the age of onset of menopause have focused on genes from the estrogen-production pathway or vascular components.

In the new study, published online Jan. 22 in Nature Genetics, the research team identified 13 novel loci associated with menopause onset, while confirming four previously established loci. Most of the 17 loci are associated with genes related to DNA damage repair or auto-immune disease; others are linked to hormonal regulation.

The authors said they expected further research to identify "a substantial number of additional common variants" that impact age of menopause, and that many of them will be located in genes identified in their study. The study examined more than 50,000 women of European descent who had experienced menopause between the ages of 40 and 60.

The research team noted that a large-scale study of menopause onset in African-American women is underway, which will help to determine whether the genetic variations that affect menopause onset in African-American women are similar or substantially different for women of primarily European descent.

Colourful coral could pave way for cancer cure

The vividly fluorescent cluster was found in waters off Lord Howe Island, 600km east of the Australian mainland, with some displaying rich reds that were difficult to find and in high demand for studies of cancer cells.

Egg cells from stem cells can be applied in infertility treatment

Stem cells extracted from human ovaries can be used to generate egg cells to be applied in infertility treatment, said researchers at Massachusetts General Hospital as quoted by media reports Monday.

Lead researcher Dr. Jonathan Tilly said: "The discovery of oocyte precursor cells in adult human ovaries, coupled with the fact that these cells share the same characteristic features of their mouse counterparts that produce fully functional eggs, opens the door for development of unprecedented technologies to overcome infertility in women and perhaps even delay the timing of ovarian failure."

According to the research team, a rooted belief is that women are born with a complement of egg cells that must last throughout life.

The research was funded largely by the National Institutes of Health in U.S.

Tilly co-founded a company, OvaScience Inc., trying to develop the findings into fertility treatments.

Y chromosome not to become extinct

The Y sex chromosome of men will not become extinct, according to a study published on Wednesday in the journal Nature.

Researchers compared the chromosomes of humans to a Rhesus monkey, a species that separated from human ancestors 25 million years ago, and to chimpanzees, which separated 6 million years ago.

The data show that the genetic decay in the Y chromosome was quick at first, but then became minimal in recent history - there is no further gene lost within the past 6 million yeard.

"The Y is not going anywhere and gene loss has probably come to a halt. The genes (in Y chromosome) that remain on it have critical biological functions, and that means they are going to survive," said Jennifer Hughes from the Whitehead Institute in Cambridge, Massachusetts, the United States.

"We can't rule out the possibility it could happen another time, but the genes which are left on the Y are here to stay," she added.

The finding challenged the previous researches which suggested the Y chromosome may become extinct in five million years' time, based on the rate at which genes are disappearing from the chromosome.

UK animal-human hybrid embryos trigger controversy in world

News of animal-human hybrid embryos in UK has caused a stir all around the world, according to a report of British newspaper Daily Mail.

155 "admixed" embryos, containing both human and animal genetic material, have been created since the introduction of the 2008 Human Fertilisation Embryology Act, Daily Mail said.

Although the scientific sensation has drawn controversy around the UK, this kind of experiments are licensed in this country.

The 2008 Human Fertilisation and Embryology Act legalized the creation of a variety of hybrids, including the creation of "cybrids" in which a human nucleus is implanted into an animal cell.

Following are several stills from the U.S. movie "Splice" of 2009:

A still from the U.S. movie "Splice" of 2009 (Photo Source:Chinadaily.com)