Dolly the sheep firm

PPL creates gene-spliced pigs

Reuters 11apr01

LONDON - Scottish biotechnology firm PPL Therapeutics Plc, creator of Dolly the sheep, said on Wednesday it had produced the world's first transgenic cloned piglets.

The five youngsters each have a foreign marker gene in their DNA structure, demonstrating the viability of a technology which may one day lead to the production of genetically-engineered pig organs for use in human transplant operations.

PPL, which on Tuesday was forced to drop a 45 million pounds ($64.40 million) fund-raising plan because of market conditions, first hit the headlines in 1996 when its collaboration with the Roslin Institute near Edinburgh created Dolly, the world's first cloned mammal.

Its most advanced research involves producing medicines in the milk of transgenic sheep but the company also hopes to produce so-called "knock-out" pigs whose kidneys, hearts and other organs would be suitable for use in humans.

A "knock-out" pig would have a specific gene that leads to the human immune system rejecting pig organs being inactivated.

PPL research director Alan Colman the production of transgenic cloned pigs at the company's U.S. unit in Blacksburg, Virginia, was a significant milestone in the development of pig donor organs.

Pigs are the preferred species for animal-to-human transplants because of their size and genetic make-up. Their use is also viewed as ethically more acceptable than apes.

Nonetheless the whole idea is fraught with controversy and a number of scientists are concerned about the theoretical risk of viruses being spread from animals to humans.

PPL said clinical trials could start in four to five years time.

Analysts have estimated the market might be worth $5 billion a year for solid organs alone, with as much again possible from cellular therapies such as transplantable cells to produce insulin.

11:23 04-11-01

***************************************************************

11) American Scientist magazine

Ecology of Transgenic Crops Genetically engineered plants might generate weed problems and affect nontarget organisms, but measuring the risk is difficult

Abstract: Concerns about risks posed by transgenic agricultural crops generally focus on direct risks to human health. There is, however, a set of potential ecological risks that bears equal scrutiny. Transgenic crops designed to resist or kill herbivores, for example, may spread their genes to non-crop species, producing virulent weed species. Likewise, these crops may negatively affect populations of beneficial insects, as was the case in the recent controversial finding that transgenic corn may increase mortality in monarch butterfly caterpillars. Assessing such risks is inherently difficult, but the impact of ignoring them could be devastating.

Click link below to read entire detailed article: http://www.sigmaxi.org/amsci/articles/01articles/marvierintro.html