Sacramento Bee, August 18th, 1999

Dark Side of Cloning Perplexes Scientists

By Eddie Lau, Science Writer

TAHOE CITY - The cute and healthy-looking ones get names such as Dolly, Amy, Betty and Daisy. They get their pictures taken. But for every good-looking lamb and calf conceived in a laboratory dish, a confounding number of animals come out oversized or malformed or aren't born at all.

The problems are so persistent in artificially reproduced and genetically engineered animals that some scientists are devoting their full attention to what they call Large Offspring Syndrome.

"I think at the moment, (the syndrome) is the norm," one of those scientists, Lorraine Young, said with a sigh.

Young is talking about the topic a lot this week with colleagues from around the world, gathered for the Transgenic Animals in Research Conference organized by the University of California, Davis, by the shores of Lake Tahoe. A researcher at the Roslin Institute, Young is studying the syndrome in sheep and calves, which seem to develop abnormalities the most.

The Roslin Institute is the Scottish laboratory that became famous two years ago for producing a sheep named Dolly, the first clone made from an adult animal's cell. Back then, animal scientists were excited - and some euphoric - over the notion that a grown-up cell could be reprogrammed to make a new being.

Today, animal cloning, if not quite commonplace, no longer is spectacular. Dolly was followed by more sheep clones, cattle clones and mice clones. But the chances of producing healthy young from cloning and other reproductive techniques involving genetic manipulation are still quite low, 10 percent at best. Now scientists want to know: Why doesn't it work more often?

At UC Davis, six calves born in a study of Large Offspring Syndrome weighed from 7 percent to 68 percent more than their normal counterparts. Their average weight was 96 pounds; 75 pounds is normal, said Dr. Marcelo Bertolini, a Brazilian veterinarian working on a doctorate in animal science at UCD.

Besides being big, some of the abnormal calves - though not all - have other problems, Bertolini said: cleft palates, difficulty breathing, low oxygen levels in their blood, retarded ability to stand and suckle. One calf nicknamed Goofy was born with a disproportionately small head and hooves, long body and big joints.

Even if researchers don't fiddle with the genes of their experimental offspring, the animals may have strange development. The calves in the UC Davis study are merely products of "in vitro fertilization", a procedure in which sperm and eggs are combined in petri dishes to produce embryos that are then transferred into cows wombs.

The same technique has been used for 21 years to help infertile humans conceive, with no obvious ill effects in the babies. What is the difference?

"It's extremely curious," said Young, noting that mice also seem not to experience the syndrome. "We don't understand that yet."

Just because it hasn't happened in people doesn't mean it won't, worries Young. "I would feel happier knowing (the cause)," she said.

The prospect of hidden health problems troubles Dr. Torben Greve, a veterinary researcher in reproduction at the Royal Veterinary Agricultural University in Denmark. 'The main problem, to me, is the subtle differences that nobody wants to admit to," Greve said. "What if life expectancy is changed? Or incidence of heart disease might be increased."

One obvious difference between the way calves and human offspring are conceived in laboratories has to do with what's lining the petri dish. Until they are moved to a womb, embryos grow on a bed of nutrients, a mixture of amino acids, sugars, hormones, antibiotics and so forth. For each species, the culture medium is different.

Heiner Niemann, an agricultural government researcher in Germany, found he could manipulate several genes controlling fetal development in cattle by changing the culture medium. Cultures, he concluded, "do not mimic the (natural) situation sufficiently well."

In her search for answers Young is focusing on special genes, known as imprint genes, that evidently control fetal growth.

She said scientists theorize that imprint genes from the father promote growth because it's in the father's interest to produce the biggest and strongest babies. The mother's interest, however, is best served by minimizing damage to the womb so she can bear several babies, so her imprint genes limit growth. Somehow, the theory goes, manipulations of eggs and sperm outside the body topple the balancing act.

If this is true, Young said, the challenge is to identify the factors controlling the imprint gene. "I don't think (the problem of abnormal offspring) has to be the norm," she said. "We think we can improve it."

Sacramento Bee, August 19th, 1999

A Silk Bonanza Sought in Goats' Milk

By Eddie Lau, Science Writer

TAHOE CITY - You've heard the old saying about making a silk purse out of a sow's ear? Well, molecular engineers are on the verge of making spider silk out of goat's milk.

The transformation may have no literary value, but the researchers at Nexia Biotechnologies Inc. in Canada expect their invention to have great commercial worth.

The strong, elastic, glossy, lightweight material could be useful for protective clothing and helmets, vehicle tires, surgical sutures, cable sheathing, even cosmetics, said Costas Karatzas, vice president of research and development at Nexia.

"It has been estimated that a single bundle of spider silk the thickness of a pencil could stop a Boing 747 in flight!" Karatzas wrote in an abstract about the Nexia venture.

Karatzas described the spider silk project Wednesday to an enthusiastic audience of fellow scientists at the Transgenic Animal Research Conference organized by the University of California, Davis, at the Granlibakken Resort and Conference Center.

"It's a marvelous idea," said Bob Wall, a livestock researcher at the U.S. Department of Agriculture in Beltsville, MD., one of 150 meeting participants. Most of the scientists attending specialize in making animals with foreign genes - so-called transgenic animals.

The ability to swap genes among animal species is key to mass-producing spider silk, which Karatzas called the strongest material in the world. Although people have been fascinated for centuries with the spider's talent for spinning sturdy, flexible webs, they have been unable to harness that power as they have with silkworms to make silk fabric.

"Why are there no farms of spiders?" Karatzas asked rhetorically, and explained, "Spiders are predatory and solitary creatures." You can't rear them together, in other words.

Goats, you can. So using a couple of genetic engineering techniques - including nuclear transfer, the technique that gave rise to Dolly the sheep clone - Nexia scientists inserted the spider's silk-making gene into the DNA of goat ova. As the altered ova developed into embryos, they were placed into the wombs of surrogate goat mothers.

Karatzas said some goats are just now giving birth to what the company expects will be kids containing the spider gene. If the experiment works, the female goats eventually will produce milk containing the protein from which cobwebs are made. Then, the liquid protein will be extracted and purified, and coagulated under chemical solvents including acetone, which transforms the liquid into solid fibers.

Although Nexia hasn't yet milked a goat, Karatzas said the company tested the concept by putting the spider gene into mice. As hoped, the web protein was in the mouse milk.

One possible reason it worked is that mammary glands and spider silk glands are similar, Karatzas said. Inside the spider's body the silk protein is a liquid crystal. As it's extruded from the spider, the protein becomes dry and fibrous.

Karatzas said 30,000 species of spiders are known to produce silk. And they produce more than one type of a piece. The common garden spider, for example, makes six different kinds of silk, he said.

One silk Nexia is targeting is dragline, the stuff a spider uses to drop down from the ceiling corner. Karatzas said dragline can be stretched 30 percent of its length before snapping.

The type of silk that spiders use to make the interiors of their webs - the parts that snag unlucky insects for lunch - is highly elastic, able to stretch 200 percent before breaking, Karatzas said. Such fiber could be used in the same manner as Lycra.

Nexia, located west of Montreal, has its eye on uses for the liquid form of spider silk as well. Because of its glossy sheen and strength, cosmetics manufacturers are interested in it as an ingredient of mascara and nail polish, Karatzas said.

The researcher could not say when the company expects to sell spider silk commercially, but the goats they are using are bred to mature quickly. The females are ready to become pregnant - and therefore produce milk - at 3 months old, less than half the age of a typical goat. Soon, Karatzas quipped, "We're not going to be milking animals; were going to be silking animals."