By Chang Jia-fong

The cloning technology in T aiwan has made significant progr ess through the team efforts of the Council of Agriculture’s Livestock Research Institute and other related bodies, in fact, achieving tw o breakthroughs. The first one is the natural breeding of an offspring by cloned sheep “Bao Siang.” This is an unprecedented case in Taiwan .

The Council of Agriculture's Livestock Research Institute successfully carries out the natural breeding of the cloned goat's offspring.

Another breakthrough sees the cloned sheep “ Bao Yu,” which is carrying exoge nous human factor VIII genes, successfully give birth to an offsprin g named “Bao Bei.” After examination, “Bao Bei” was found as also carrying the same exogenous human factor VIII genes. This serves as a major step in the development of gene cloning technology in Taiwan.

According to Li Shan-Nan, the deputy director of the Livestock Research Institute, Council of Agriculture, Taiwan has been aggressively engaged in cloning technology. For example, after many years of research, embryonic transplant technology in Taiwan is advancing steadily, and the system of in vitro embryos is established. On October 9, 1998, the first creation from the in vitro embryo production system named “Guo Ching cattle” was produced. In addition, the case of “Dolly” in 1997 offered a new way of thinking globally in revealing the secret code of cloning technology. Based on these opportunities, the Livestock Research Institute began its aggressive research into cloning technology. In 2000, they used bovine cumulus cells as the nuclear source for the development of nuclear transfer technology. In 2001, they produced a series of cloned livestock, and “somatic cell cloning” was successfully carried out. After one year of study, a cloned goat was produced successfully from goat ear cells, which propelled the cloning technology in Taiwan to a new era.

According to Chen Li-Ren, a group leader in the Physiology Group of the Livestock Research Institute, the core of cloning has three major directions: 1. To improve the quality of livestock by increasing high-quality livestock populations; 2. In coordination with gene transfer technology, cloning can be used to produce pharmaceutical proteins by means of bioreactors from the livestock’s mammary system; 3. To combine with stem cells in order to develop an animal model for medical therapeutic cloning.

Chen Li-Ren stated that the current platform for laboratory cloning technology is very solid, and excellent results have been obtained in the stem cell research. In the future, it is hoped that the two laboratories can be combined to develop an animal model for medical therapeutic cloning.

Chen further explained that basic “medical cloning” involves the extraction of human somatic cells, and cloned embryos can be made using cloning technology. Then, stem cells are isolated from the embryos producing the stem cells necessary for cell transplants. For example, if there is a heart problem, then the produced stem cells can be used to induce myocardial cells in order to repair heart damages. Because the source of these medically cloned cells comes from the patient, thus the potential for rejection will not occur. However, Chen indicated that this is still a theory, and the concept cannot be tested with humans. Therefore, it is hoped that an animal model should be established for experimental studies. If it is successful with animals, then this technology can be applied to human medicine. This is one of the important goals of the Physiology Group of the Livestock Research Institute.

‘Bao Bei’ inherits exogenous human factor VIII genes

Li Shan-Nan stated that the successful performance of “transgenic cloning” by the Livestock Research Institute involves a complete transfection of exogenous genes into somatic cells. After screening to ensure the successful transfection, transfer of the nucleus is then performed. For instance, “Bao Bei,” inherited the exogenous human factor VIII genes from the mother “Bao Yu.” On the other hand, the somatically cloned “Bao Siang,” did not carry any exogenous genes. According to Li Shan-Nan, the most undesirable result in the process of cloning involves an overweight fetus, incomplete organ developments, premature death of the embryo, and respiratory system problems. These problems occurred during the process of cloned embryonic growth, the implanted gene of the nucleus providing cells is unable to be reprocessed. This is closely related to DNA methylation. Li Shan-Nan said that in order to better handle the process of gene cloning technology, the Livestock Research Institute has been working very hard for a long time. Because of the possibility that the cloned newborns might exhibit physical abnormalities, thus genetic regulating methylation is an important factor.

Li Shan-Nan has also pointed out that the invention of cloning technology will be a major contributor to human medicine in the future. First, technological platforms that can successfully clone animals can serve as models for genetic modifications in animals. Second, the cloning technology can be utilized to increase the population of high-quality animals. In addition, the Livestock Research Institute is working hard in combining cloning and stem cell technologies, hoping that a new way can be found in medical cloning. According to Li, gene transfer is a newly emphasized goal in the Institute. They hope that using transgenic technology, livestock animals can serve as bioreactors in order to produce proteins that can be used pharmaceutically and hence can be applied to human medicine.

Laboratory cloning technology shows significant progress in Taiwan, and excellent results have been obtained in the stem cell research.

Medical market eyes benefit from gene production Currently, the exogenous human factor VIII genes produced by the Livestock Research Institute can be used to treat type A Hemophilia. In terms of production value, each gram of Factor VIII can cost US$2.9 million dollars. However, Li emphasized that products made with biotech medicine via cloning technology require various tests and many-step safety procedures before they may be marketed. He also frankly stated that the current technology is still far from producing biotech pharmaceuticals, and such production is a future goal that still requires research. Once the technological platform is established, the need of therapeutic proteins in the future can be produced through a similar method of gene transfer. The invention of such platforms can become an important basis for profit in the medical market.

Li said that research in cloning technology is a difficult task to perform. Many countries are heading in this direction, and Taiwan is no exception, because cloning technology can enhance the competitiveness of biotechnology in Taiwan.

※ What is “DNA Methylation?”

According to a former senior member, in the cloning research of Livestock Research Institute, Dr. Shen Peng-Zhi, (currently working in the National Pingtung University of Science and Technology), that DNA methylation is a method used by the cell to turn off its genes. Through the level of methylation in the cell, it can regulate the specificity of the genes: the higher the level of methylation, the lower the gene expression. In other words, methylation is a mechanism of regulating gene expression without alerting the genetic code in an organism.

※ What is “gene transfer?”

Guo Ting-Yong, a research assistant of Livestock Research Institute states, that gene transfer means inserting a section of exogenous gene not belonging to an animal into the chromosome of this animal with ease through some physical or chemical methods, so the piece of gene stays in the chromosome. The animal with a successful gene transfer is a transgenic animal. The operation needs to be very carefully carried out. If the timing and location are not precise, then it is a waste of time.