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Showing posts with label sexual reproduction. Show all posts
Showing posts with label sexual reproduction. Show all posts

Monday, August 24, 2009

US doctor offers British couples chance to choose sex of child

Jeffrey Steinberg, a US doctor, is offering British couples the chance to choose the sex of their child at his New York clinic.

Dr Steinberg provoked anger earlier this year when he said his fertility clinic could allow parents to produce "designer babies" - choosing eye, hair, skin colour and gender.

Under American law, he is allowed to use pre-implentation genetic diagnosis (PGD) to reveal an embryo's sex. In Britain, it can only be used in screening for genetic diseases.

Half of the embryos undergoing tests in Dr Steinberg's laboratory reportedly belong to British couples while four more will be tested next month.

"Britain is far more conservative than it used to be. They were the innovators but now they've got handcuffs on," Dr Steinberg said.

"From a business standpoint, it's the best thing going. From a medical standpoint, it's a travesty."

America has allowed sex selection - known by its supporters as "family balancing" - since 2001, but US pro-life groups have criticised the destruction of embryos deemed undesirable. Earlier this year, the Pope attacked the "obsessive search for the perfect child" and said a "new mentality is creeping in that tends to justify a different consideration of life and personal dignity".

In Britain, officials have warned parents who go overseas for treatment - often after spotting advertisements on the internet - that they should understand the relevant laws and the impact of the selection on any child who is subsequently born.

Other American medical centres have reported receiving interest from British couples, including the Genetics and IVF Institute in Virginia.

The institute said that up to 15 per cent of the 400 PGD cases it handles a year come from abroad. It said it counsels parents before the procedure.

Gary Harton, its PGD scientific director, told The Times that he tells British patients: "You're no different to any other patient. You're here to get what you want. To get a baby."

Wednesday, August 12, 2009

Scientists Force Fungus to Have Sex to Create Biofuel

Fungus

Austrian scientists are putting the ‘fun’ in ‘fungus’ by forcing organisms which are usually asexual to have sex instead.

The hope is that the fungus would then be easier to breed, which would allow researchers to create organisms that are more efficient at degrading cellulose for the purpose of making biofuel.

Originally discovered in the Solomon Islands during World War II eating away at the canvas and garments of the U.S. Army, scientists have long known that the soil fungus Trichoderma reesei was particularly good at converting cellulose– a major component of plant biomass– into glucose. But until now it has been difficult for researchers to improve the fungus because it was believed to be asexual.

Due to the fact that sexual organisms exchange and mix their genetic material when they breed, their traits can be more easily manipulated artificially. Under the assumption that Trichoderma reesei was asexual, scientists looking to improve the fungus were instead limited to techniques like dosing the fungus with radiation or chemicals in order to alter its genetic profile. But that process only created random or unpredictable mutations.

But for the first time since its discovery 50 years ago, scientists can now make the fungus have sex.

Past studies have shown that Trichoderma reesei is genetically identical to another species of fungus, Hypocrea jecorina, which it so happens is capable of sexual reproduction. The primary difference between the two organisms was that Hypocrea jecorina seemed capable of assuming both the male and female roles, whereas Trichoderma reesei seemed only capable of assuming the male role.

So scientists got a novel idea: Why not breed the male-oriented Trichoderma with a female-oriented Hypocrea? The result was a successful mating– the Trichoderma lured into having sex could now be artificially selected for their advantageous genetic traits.

The findings could have largescale ramifications. Researchers want to employ the organisms to make use of the otherwise useless cellulose in sawdust, weeds and other plant scrap to make biofuel. Thus, the primary benefit of fungus sex could be to turn bush into biofuel. But the newly sexualized fungus can also help farmers. Since Trichoderma includes species that help plants by killing harmful fungi, they can be put to use protecting crops we use for food.

Source: LiveScience

Image Credit: V. Seidl, Vienna University of Technology