M.B.A. / The debate over plant biotechnology and genetic engineering (GE) is surrounded with controversy. On the one side of the debate, phrases such as `Frankenfood' and `terminator seed' have been used to describe food and seed resulting from plant biotechnology. On the other hand, Agricultural Scientists see biotechnology and genetic engineering as a solution to keep feeding and clothing the increasing world population with static or reducing world resources. Many farmers in developing countries eke out a living based on the production techniques that are becoming increasingly unaffordable because of increasing inputs cost and are no longer producing enough output to provide adequate access to food. Plant biotechnology holds the potential for increasing the productivity of agriculture in developing countries. New crop varieties are developed which are resistant to insects and are tolerant to certain non-selective herbicides. All these plant biotechnology developments are said to help reduce the cost of inputs, protects yields and reduce environmental contamination with toxic insect sprays. For many commercial farmers, cotton production is the only possibility they have to produce a cash crop but spraying to control insect pests is required several times during the season resulting in high input costs. An alternative to spraying is to introduce a built-in defense into the plant itself to combat insect damage. The introduction of the insecticidal gene from the bacterium Bacillus thuringiensis (Bt) into the cotton plant trough biotechnology, has secured a built-in defense against the most common insect family in cotton namely the lepidopteran caterpillar. Cotton engineered with such genes was introduced into commercial production for the first time in 1996 with over 1.8 million acres planted with transgenic cotton in the US. Following early trials, Bt-cotton has since the 1998/99 growing season been commercialized in South Africa. Since the introduction of genetically engineered (GE) crops, US farmers have rapidly adopted most of them. Analyses by USDA's Economic Research Services (ERS) and others indicate economic benefits to many farmers adopting first-generation GE crops. This research study was carried out to determine to what extend the South African cotton growers embraced this kind of technology through usage thereof and if they benefited as much as other cotton farmers world-wide. The specific research objectives for this study were as follows: An evaluation of the adoption rates and benefits derived from plant biotechnology on a worldwide base through literature. An evaluation of the acceptance and penetration of Bt-cotton amongst the South African commercial cotton growers. To determine the benefits of Bt-cotton to the South African commercial cotton growers. To determine to what extend the South African cotton growers benefited economically through the use of the Bt-cotton trait. To identify segmental differences in the adoption of the Bt-cotton trait amongst commercial cotton growers in South Africa. The main findings of this research indicate that almost three quarters of the cotton hectares surveyed were planted with the Bt-cotton trait and that almost ninety percent of cotton growers surveyed, adopted the Bt-cotton trait in the 2001/2002 season. Comparing the benefits derived from Bt-cotton in South Africa to those in other countries, it can be concluded that the South African commercial cotton growers had equal results. Most of the cotton growers in South Africa experienced yield increases with a substantial reduction in the use of insecticides. This resulted in higher gross margins from Bt-cotton compared to the non-Bt cotton or commercial cotton varieties. The South African commercial cotton grower has benefited agronomically, economically and environmentally through the adoption of the Bt-cotton trait. Future introductions of plant biotechnology traits such as herbicide tolerance will further enhance the production potential of cotton.

Masters of Science / Metagenomics has been successfully used to discover novel enzymes from uncultured microorganisms in the environment. In this study, metagenomic DNA from a Malawian hot spring soil sample was used to construct a fosmid library. This metagenomic library comprised of more than 10000 clones with an average insert size of 30 kb, representing more than 3.0 x 108 bp of metagenomic DNA (equivalent to approximately 100 bacterial genomes). The library was screened for cellulase activity using a Congo red plate assay to detect zones of carboxymethylcellulose hydrolysis. This yielded 15 positive fosmid clones, of which five were further characterised for activity and thermostability using the 3, 5-dinitrosalicylic assay. Two of the five fosmids (XP008C2 and XP026G5) were selected for DNA pyrosequencing. The full sequence of the XP008C2 (29800bp) fosmid insert is presented in this study and genes thereon were chosen for further study. / South Africa

In modern society, children are acknowledged as bearers of both children‟s rights and all other rights in the Bill of Rights which generally apply to children. One important right, outside of section 28, is that of bodily integrity or the right to control and decide what happens to their body. Therefore, children theoretically have the right to consent to medical treatment and surgery. However, children are generally deemed to lack the necessary maturity to make decisions of this nature and require parental consent before any medical procedure may be performed. Following the enactment of the Children‟s Act 38 of 2005, the age of consent for medical intervention was lowered to the uniform age of twelve. Children above the age of twelve are recognised as having the capacity to make their own decisions in respect of bodily integrity, whereas those under twelve still require parental consent. While this may be a positive evelopment, it is potentially problematic for two groups of children, known as „benefactor children‟ and „saviour siblings‟. In the last 50 years, there has been a noticeable advancement in the field of genetic research. One such development is the possibility of creating one child to save the life of another through tissue or organ donation. This has provided options to parents of children with life threatening conditions where before, there was little hope of a cure. Now, at the request of these parents, children can be specifically “genetically engineered” as an embryo, to become a tissue or organ match to a sick sibling. These children are known as „saviour siblings‟. Another group of children has emerged. While not the result of “genetic engineering”, they serve a similar purpose in being potential life-saving donors to an ill sibling and are known as „benefactor children‟. Both categories of children enjoy the protection of fundamental rights. For those who are under twelve years of age however, the right to bodily integrity can be infringed upon by the proposed surgical removal of organs or tissue for the benefit of a sick sibling, based purely on a parent‟s consent. At stake too, is the right to reproductive autonomy. Parents bear children for a number of different reasons, which can include raising a child to save the life of another. As they have the right to reproductive autonomy, adults are able to decide when they want children and for what reason they want children, which can include the various techniques used to bring about „saviour siblings‟. However, as rights are mutually interrelated and nterdependent, they cannot be viewed in isolation. Therefore, it must be asked: does a person‟s right to reproductive autonomy, as guaranteed by the Constitution, justify interference with an embryo? As an embryo is not recognised in South African law as a legal subject, it will be difficult to justify interference with this right on this basis. The right to consent to medical intervention only from age twelve was described as potentially problematic for „benefactor children‟ and „saviour siblings‟, as parents with seriously ill children may become so emotionally burdened, that they place the welfare of the sick child over that of the healthy child. Thus, it is possible that parents will consent to any and all procedures on the „benefactor child‟ or „saviour sibling‟, regardless of the implications to the health and suffering of the healthy child. Section 28(2) of the Constitution states that the child‟s best interests are of paramount importance but, it must be asked, whose best interests are more important when more than one child is involved? As this is a decision parents are incapable of making at that time, the decision should be made by a neutral, impartial and unemotional third party such as the Court, which can be assisted by the Family Advocate and an ombudsman, who are experts in assisting children and promoting their best interests. Presently, South African law does not expressly address „saviour siblings‟. However, with few changes to the National Health Act and other Regulations, this is an area which could be regulated in time. These changes could include finalising the draft regulations as well as providing a list of the medical and dental purposes for which blood and tissue can be removed and should make specific reference to the removal of tissue, blood or blood products to treat a sick sibling. It is also imperative that South Africa regulates these matters now, as „saviour siblings‟ are no longer simply a matter for the future. Furthermore, legislation needs to be amended and enacted to prevent the law from becoming out-dated and redundant, leaving „benefactor children‟ and „saviour siblings‟ vulnerable while law is being drafted. In that international law is silent on the matter, South Africa would be well advised to consider foreign law such as the United Kingdom, in developing its law. As the United Kingdom has developed a National Board, so too should South Africa, as this would assist in regulating „saviour siblings‟ by allowing members to review each proposed case of „saviour siblings‟. This is merely one recommendation of several which could facilitate a smooth, controlled regulation of a highly emotional topic. Children remain one of the most vulnerable groups in society and their rights are often susceptible to infringement or abuse. It is incumbent on the law to ensure that, wherever possible, these rights are protected, especially as science continues to advance and it becomes more difficult to determine what is morally correct.

Advancements in genetically based technologies have begun to allow us to better understand the relationships between underlying neural activity and the patterns of measurable behavior that can be reproducibly studied in the laboratory. As this field develops, there are key limitations to the currently available technologies hindering their full potential to deliver meaningful datasets. The limitations which are most critical to advancement of these technologies in behavioral neuroscience are: the temporal resolution at which physiological events can be windowed, the divergent molecular pathways in signal transduction that introduce ambiguity into the output of activity sensors, and the impractical size of the tool’s genetic material—requiring 3-4 separate AAV vectors to deliver a fully functional system into a cell. To address these limitations and help bring the potential of these types of technologies into better realization, we have engineered a nucleus localized light-sensitive Ca2+-dependent gene expression system based on AsLOV2 and the downstream responsive element antagonist modulator (DREAM). The design and engineering of each component was performed in such a way to: 1) preserve behaviorally relevant temporal dynamics, 2) preserve signal fidelity appropriate for studying experience-driven neural activity patterns and their relationship to specific animal responses, and 3) have full delivery of the system’s genetic material via a single AAV vector. The system was tested in vitro and subsequently in vivo with neural activity induced by Channelrhodopsin, and could be used in the future with behaviorally-driven neural activity. To our knowledge this is the first optogenetic tool for the practical use of linking activity-dependent gene activation in response to direct nuclear calcium transduction.

Please read the abstract in Chapter 6 of this document / Dissertation (MSc (Genetics))--University of Pretoria, 2000. / Genetics / unrestricted

An Agrobacterium-mediated transformation system of purple raspberry ‘Amethyst’ was established after a series of experiments that determined the effect of genotype, inoculum density, and co-cultivation time on transformation. In this study, a plant regeneration protocol was established for ‘Joan J’ and ‘Polana’ (the regeneration protocol of ‘Amethyst’ was previously developed). Agrobacterium-mediated transformation was conducted for all three cultivars. The minimum killing level of hygromycin B and kanamycin was determined. Inoculum density and co-cultivation time were optimized. Polymerase chain reaction (PCR) verified a successful transformation of ‘Amethyst’ with the frequency of 3.3 ~ 4.4 % when leaves were infected with Agrobacterium EHA105 at the cell density of OD600 0.3 and co-cultivated for 3 days in the medium with 25.0 mg∙l-1 kanamycin. Transgenic lines with the PtFIT gene were hydroponically grown under iron sufficiency or deficiency. The real-time quantitative PCR verified the gene expression in response to iron sufficiency and deficiency conditions.

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The following work presents the ongoing philosophical debate regarding the use of biotechnology to improve human capabilities and attempts to apply the insights drawn from these debates to the regulation of non-medical uses of reproductive technology. After presenting the criticisms towards a hardline approach that would ban all attempts to enhance humans, we evaluate various alternative frameworks and adopt a framework called Genetic Justice, which can be understood as an application of Rawlsian distributive justice to biological assets. After improving on this moral framework by incorporating various institutional considerations into it, we apply it to the evaluation of non-medical uses of a screening technique called preimplantation genetic diagnosis and propose recommendations for its regulation.

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