Tag: Genetic Engineering

Chinese Researchers Claim Human/Rabbit Hybrid

Chinese researchers claimed in August to have created the first human/rabbit hybrid embryo.

The researcher was carried out at Shanghai Second Medical University and details about the research was published in Cell Research, a bimonthly peer reviewed journal of the Shanghai Institute of Cell Biology.

The researchers claim they fused skin cells from a number of human source with rabbit cells that had most of their rabbit DNA removed. According to the researchers, 400 of the hybrids grew into early embryos and more than 100 survived to become blastocysts.

There are many good reasons, however, to be skeptical that the researchers actually managed to create hybrid embryos.

According to a United Press International story, the report on this research had been submitted and rejected by several more reputable journals over the past two years. The study has been rejected for publication because both the draft and the version published in Cell Research omit data that would make it possible to confirm that the researchers actually resulted in embryonic cells.

And, as UPI tactfully puts it, “researchers in China have gained a reputation for making bold claims about cloning and stem cells that, all too often, prove false.”

Sources:

Scientists Doubt Chinese Claim of Rabbit-Human Clone. United Press International, August 15, 2003.

Cloning yields human-rabbit hybrid embryo. Rick Weiss, Washington Post, August 14, 2003.

PPL Therapeutics Plans to Cull Sheep

PPL Therapeutics, which in 1996 made world news with the cloning of Dolly the sheep, announced in July that a downturn in its fortunes would lead it to cull most of its flock of 3,000 genetically modified sheep.

PPL Therapeutics produced the first transgenic sheep in 1991. The sheep are genetically modified to express recombinant Alpha-1 Antitrypsin (AAT) in their milk. AAT was to be used to treat lung disorders, but in June drug company Bayer announced that it was ending its three year partnership with PPL Therapeutics on trials of AAT.

PPL Therapeutics does plan to keep some of the sheep for possible future breeding programs.

Source:

Thousands of sheep face cull after drugs trial shelved. Ananova, July 15, 2003.

Dolly firm to cull its sheep. The BBC, July 15, 2003.

Glow In the Dark Fish First of Many Future GM Pets

The first genetically modified pet has already gone on sale in Taiwan and will likely be on sale in the United States soon. The Night Pearl is a genetically modified zebrafish that glows in the dark.

The fish grew from research conducted by HJ Tsai of the National Taiwan University. Tsai simply wanted to make the organs of fish easier to observe, and solved that problem by inserting a jellyfish gene to make the organ glow. Instead, he ended up making the entire animal glow.

Fish produce company Taikong Corporation reached an agreement to fund Tsai’s research in exchange for the right to use his techniques. Now Taikong is marketing fish that glow red and green. As might be expected, this advancement is being greeted with wildly different views.

Some, such as Keith Davenport of the UK’s Ornamental Aquatic Trade Association is outraged. Davenport told The Observer,

This is the thin end of the wedge. You could put all sorts of different genes in animals and do all sorts of damage.

Among fish dealers in the United States, however, there is the obvious excitement that these fish will be big sellers. Nevin Bailey of AquariumFish.Net told The Chicago Tribune,

If they can actually do this, it will be the greatest thing since popped corn. There’s a lot of pent-up demand [for the glow in the dark fish] . . .My gosh, if they ever made one that was red, white and blue, every Marine in the country would buy one.

Well, at least until they look at the price tag. At a $17.40 suggested retail price for each fish.

Source:

‘Fluorescent fish’ give the green light to GM pets. Robin McKie, The Observer, June 15, 2003.

Bioengineered pet fish are a reality in Taiwan. Jason Dean, Dow Jones News Service, May 12, 2003.

Australia Looks to Genetically Engineered Virus to Stop Mouse Population Explosions

Australia has a regular problem with explosions in its mouse population that occur in roughly four year cycles. The number of mice quickly increases to billions and costs Australian agriculture upwards of US $90 million in crop damage.

The problem is so severe that Australian researchers are currently investigating an exotic solution to prevent such population explosions — a genetically modified virus that renders female mice sterile.

The virus is a modified form of he herpes virus that is spread by mouse-to-mouse contact. Once it infects a female mouse, it will prevent sperm from fertilizing eggs. Researchers at Australia’s Co-operative Control of Pest Animals has shown the modified virus works in the laboratory setting, and now wants to test the virus in the field.

That, however, will have to wait for extensive testing to ensure that the virus will not jump the species barrier and infect other animals besides mice. But Australia has experience with using such solutions. It used myomatosis disease 50 years ago to control the rabbit population, and in the 1990s used the calci virus to lower rabbit populations. The calci virus killed an estimated 90 percent of the country’s rabbit population, allowing some ecosystems that were overrun by the animals to begin to recover.

Sources:

Australia invents new mousetrap with herpes virus. Reuters, April 8, 2003.

NT Queens’s Birthday Honours. ABC Rural, October 6, 2002.

Nexia Biotechnologies to Work on Nerve Gas Antidote from Goat's Milk

Nexia Biotechnologies made headlines in 2002 when it announced it had created genetically modified goats that expressed a protein unique to spiders its milk. This month Nexia announced that it would work with the Canadian military to develop a genetically modified goat that would express a powerful nerve gas antitoxin in its milk.

Its research there will focus on production of a recombinant version of butyrycholinesterace (BChE). BChE is found in small quantities in the blood of many animals, and acts as a defense against nerve agents. It binds with the components of nerve agents and renders them harmless within the blood stream. Of course in a full-fledged nerve gas attack, this small amount of naturally occurring BChE is quickly overwhelmed.

Nexia will try to create a GM goat that produces BChE in large quantities that could then be prepared as an injection which military forces could use on the battlefield to better protect themselves against nerve agents such as sarin gas.

According to Nexia, studies in animals have shown that injections of relatively large amounts of BChE have protected lab animals from such agents, but the inability to produce large quantities of it has precluded BChE from applications in human beings.

Source:

Fighting Nerve Gas: Would Use Milk of Transgenic Animals. National Post, April 2, 2003.

Protexia? – A Bioscavenger. Nexia Biotechnologies, 2003.

SCID Gene Cure May Have Leukemia Side Effect

The first disease ever cured by gene therapy was severe combined immune disorder (SCID) — the so-called “bubble boy” disease in which the immune system is so severely compromised that children have to live in near-sterile environments to avoid life threatening disease. But now, there is new evidence that the cure for SCID may increase the risk of leukemia among children receiving it.

In 2002, one of the toddlers who received SCID gene therapy as a baby came down with leukemia, and officials in France and the United States temporarily stopped the procedure. Now, a three year old who received the treatment as an infant has also come down with leukemia. As a result, the United States has suspended all 27 existing gene therapy studies have been suspended pending new risk assessments.

The potential for this sort of leukemia problem accompanies all gene therapies that use retroviruses, but this is the first time where this hypothetical risk has become actual. According to an NPR report, both of the children involved are responding well to treatment for their leukemia.

Source:

Gene therapy causes “leukemia-like side effect”. Nando Times.