Thursday, March 17, 2005
VIVE LA DIFFERENCE!
Science finally proves how women are genetically far superior to men:
X chromosome shows why women are different
LONDON (Reuters) - Scientists have cracked the genetic code of the female X chromosome which is linked to more than 300 human diseases and may help to explain why women are so different from men.
It contains 1,100 genes, or about five percent of the human genome, along with information that may help to improve the diagnosis of illnesses ranging from haemophilia, blindness and autism to obesity and leukaemia.
The discovery, by an international consortium of scientists, shows that females are far more variable than previously thought and, when it comes to genes, more complex than men.
"The X chromosome is definitely the most extraordinary in the human genome in terms of its inheritance pattern, its unique biology ... and in terms of its association with human disease," said Dr Mark Ross, of the Wellcome Trust Sanger Institute in Britain which led the consortium.
WHY THE DIFFERENCE?
Chromosomes, which are found in the nucleus of every cell, contain genes that determine the characteristics of an individual. Women have two X chromosomes while men have an X and a Y, which gives them their male features.
The research, which is reported in the science journal Nature, shows the Y is an eroded version of the X chromosome with only a few genes. The X chromosome is also bigger than the Y and because females have two copies, one X chromosome is largely switched off or inactivated.
But not all of the genes on the silenced chromosome are inactivated, which could explain some of the differences between men and women, according to Laura Carrel, of Penn State College of Medicine in Pennsylvania who also reported her findings in the journal.
The X inactivation also varies widely among women.
"The effects of these genes from the inactive X chromosome could explain some of the differences between men and women that aren't attributable to sex hormones," she said in a statement.
Genetic mutations and diseases such as colour blindness, autism and haemophilia that are linked to the X chromosome tend to affect males because they do not have another X to compensate for the faults.
The X chromosome is also home to many genes linked to mental retardation and to the largest gene, called DMD, in the human genome. Mutations in DMD cause Duchenne Muscular Dystrophy, a disabling and fatal disease in men.
"There are a disproportionate number of known diseases mapped to the X chromosome," said Dr David Bentley, of the Wellcome Trust Sanger Institute.
"In seeing what goes wrong, we can begin to understand the biological processes of the normal body much better," he added.
Monday, March 14, 2005
Group Warns of Shrinking Glaciers' Effect
By JONATHAN FOWLER, Associated Press Writer
GENEVA - The shrinking of Himalayan glaciers could fuel an upswing in flooding in China, India and Nepal, before creating water shortages for hundreds of millions of people across the region, a leading environmental group warned Monday.
In a report, the Switzerland-based World Wide Fund for Nature said the rate of retreat of the Asian mountain range's glaciers is accelerating because of global warming, and has now reached 33-49 feet a year.
"The rapid melting of Himalayan glaciers will first increase the volume of water in rivers causing widespread flooding," said Jennifer Morgan, head of WWF's global climate change program. "But in a few decades this situation will change and the water level in rivers will decline, meaning massive economic and environmental problems for people in Western China, Nepal and Northern India."
Himalayan glaciers feed into seven of Asia's biggest rivers: the Ganges; Indus; Brahmaputra; Mekong; Thanlwin, formerly known as the Salween; Yangtze and Yellow.
WWF noted that this ensures a year-round water supply to hundreds of millions of people in the Indian subcontinent and China.
As glacier water flows dwindle, the energy potential of hydroelectric power will decrease, causing problems for industry, while reduced irrigation means lower crop production, it said.
Nepal has an annual average temperature rise of .11 degrees Fahrenheit. The report said that flows have decreased in three of Nepal's snow-fed rivers.
In China, the report said, the Qinhai Plateau's wetlands have seen declining lake water levels, lake shrinkage, and the degradation of swampland. In India, the Gangotri glacier, which supports one of India's largest river basins, is receding at an average rate of 76 feet per year.
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On the Net:
WWF: http://www.panda.org/