Sequencing of frog genome may offer new insights into human diseases

Washington, May 7 (ANI): An international team of researchers has cracked the genetic code of an amphibian, the African clawed frog Xenopus tropicali – the latest research aimed at understanding how genes work for potential applications in human health.

The genome of Xenopus tropicalis has been analysed by an international consortium of scientists from 24 institutions, and joins a list of sequenced model organisms including the mouse, zebrafish, nematode and fruit fly.

What’s most surprising, researchers say, is how closely the amphibian’s genome resembles that of the mouse, the chicken and the human, with large swathes of frog DNA on several chromosomes having genes arranged in the same order as in these mammals.

“A lot of furry animals have been sequenced, but far fewer other vertebrates,” said co-author Richard Harland, University of California, Berkeley, professor of molecular and cell biology.

“Having a complete catalog of the genes in Xenopus, along with those of humans, rats, mice and chickens, will help us reassemble the full complement of ancestral vertebrate genes.”

The researchers found that nearly 80 per cent of all human genes associated with genetic diseases have counterparts in the western-clawed frog, Xenopus tropicalis.

This discovery could lead to a better understanding of the genetic and chemical basis for many of the human diseases.

The research, published this week in the journal Science, was led by the Department of Energy’s Joint Genome Institute (JGI) and the University of California, Berkeley. (ANI)

Human and frogs share the ‘kissing cousin’ bond

Washington, April 30 (ANI): An international team of researchers has cracked the genetic code of an amphibian, the African clawed frog Xenopus tropicali – the latest research aimed at understanding how genes work for potential applications in human health.

The genome of Xenopus tropicalis has been analysed by an international consortium of scientists from 24 institutions, and joins a list of sequenced model organisms including the mouse, zebrafish, nematode and fruit fly.

What”s most surprising, researchers say, is how closely the amphibian”s genome resembles that of the mouse, the chicken and the human, with large swathes of frog DNA on several chromosomes having genes arranged in the same order as in these mammals.

“A lot of furry animals have been sequenced, but far fewer other vertebrates,” said co-author Richard Harland, University of California, Berkeley, professor of molecular and cell biology.

“Having a complete catalog of the genes in Xenopus, along with those of humans, rats, mice and chickens, will help us reassemble the full complement of ancestral vertebrate genes.”

The researchers found that nearly 80 per cent of all human genes associated with genetic diseases have counterparts in the western-clawed frog, Xenopus tropicalis.

This discovery could lead to a better understanding of the genetic and chemical basis for many of the human diseases.

The research, published this week in the journal Science, was led by the Department of Energy”s Joint Genome Institute (JGI) and the University of California, Berkeley. (ANI)

Frogs provide clues about alcohol’s effects during pregnancy

Washington, Apr 6 (ANI): Scientists have successfully used the African frog Xenopus as a tool to identify important clues about the effects of maternal consumption of alcohol in early pregnancy.

As the Xenopus embryos are large, easy to work with and very responsive to environmental cues, they make for ideal instruments to understand early vertebrate development.

Foetal alcohol spectrum disorder (FASD) and Foetal alcohol syndrome (FAS) cause malformations in babies, including facial defects, short stature, and mental and behavioural abnormalities.

Alcohol consumption prevents normal development by inhibiting the production of retinoic acid.

Normally, the levels of retinoic acid made in different areas of the embryo provide cells with necessary information about their proper location and fate.

In the new research, it has been shown that alcohol steals away the molecules that make retinoic acid and use them for its own process of detoxification, resulting in cellular disorientation during a critical period of development.

The study, provides evidence that the characteristics associated with FASD and FAS come from competition of alcohol for key molecules in a pathway that produce retinoic acid from vitamin A.

Retinoic acid is needed for correct positioning of cells in developing embryos and by preventing its normal production.

Alcohol keeps cells from migrating to their correct positions and maturing properly.

Researchers at the Hebrew University in Israel have found that shutting down a molecule needed to produce retinoic acid, known as retinaldehyde dehydrogenase (RALDH2), increases sensitivity of developing embryos to low doses of alcohol.

On the other hand, more of the molecule RALDH2 protected embryos from the negative effects of alcohol.

The research provides evidence that alcohol ‘hijacks’ RALDH2 molecules for its own breakdown process, and steals it away from its important role in synthesizing positional and maturation cues during development.

The study has been published in Disease Models and Mechanisms (DMM). (ANI)