Magister Scientiae - MSc (Biotechnology)

Permanent URI for this collection

https://hdl.handle.net/10566/13204

Browse

Browsing by Subject "2D SDS-PAGE"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Development of a plum chromosome doubling method and proteomics and biochemical characterization
    (University of the Western Cape, 2015) Mabiya, Thembeka; Ndimba, Bongani; Mansvelt, Lucienne; Klein, Ashwil
    Chromosome doubling has become an important tool in breeding programmes as it offers the ability of introducing novel traits into existing plants. Doubled haploid plants are highly valued by both consumers and breeders as these plants usually show larger flower, leaves and fruit, thus making them more marketable. Marianna open pollinated plum rootstocks’ adaptability to different soil types and moisture conditions has been favoured in polyploidy studies as parental material in breeding programmes. The potential of the microtubule depolymerizing herbicide (oryzalin) for in vitro chromosome doubling were investigated by optimizing the concentration and incubation time of plant shoots to the antimitotic agent. Meristem tissues were treated for two time intervals (24 and 48 h) with five different concentrations of oryzalin (50, 75, 100, 150 or 200 μM) in liquid Murashige and Skoog (MS) medium. After treatment, plants were allowed to grow under a 16/8 h light/dark photoperiod at 24±2˚C for 4 weeks. One and two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry (MS) was used to separate, visualise and identify differently expressed proteins. Furthermore, changes in ROS accumulation, photosynthetic pigmentation, lipid peroxidation and antioxidant enzyme activity (SOD, APX and GR) were investigated. Flow cytometry results revealed that treatment of plants with oryzalin concentrations ranging from 75 to 150 μM induced ploidy after 24 h exposure whereas, 200 μM produced mixoploids containing both tetraploid and octoploids plants after 24 h exposure. Longer incubations of 48 h were detrimental to plant tissues as complete mortality was observed in the higher concentration (100 to 200 μM) treatments. Mass spectrometry analysis identified 14 differentially expressed protein spots that were characterized into different functional categories. ROS accumulation, the extent of lipid peroxidation and antioxidant capacity were differentially regulated in response to oryzalin treatment whereas photosynthetic pigments were significantly enhanced. The results suggests that oryzalin-induced proteins may act as potential biomarkers to improve fruit characteristics in future breeding programs whereas antioxidant enzymes play an important role in scavenging ROS in plants to enhance their adaptability to different environmental conditions.
  • Thumbnail Image
    Item
    Identification of a transducin (beta)-like 3 protein as a potential biomarker of prediabetes from rat urine using proteomics
    (University of the Western Cape, 2010) Mofokeng, Henrietta Refiloe; Ndimba, Bongani; Skepu, Amanda; Dept. of Biotechnology; Faculty of Science
    Obesity is a globally increasing disease particularly in developing countries and among children. It is mainly caused by intake of diets high in fat and the lack of physical activity. Obesity is a risk factor for diseases such as type II diabetes, high blood pressure, high cholesterol and certain cancers. Prediabetes is a condition where blood glucose levels are above normal but have not reached those of diabetes. It is difficult to diagnose, as there are no signs or symptoms. Some type II diabetes patients bear no symptoms at all and the disease is discovered late. Proteomics is a field that can provide opportunities for early diagnosis of diseases through biomarker discovery. The early diagnosis of diabetes can assist in the prevention and treatment of diabetes. Therefore there is a need for the early diagnosis of diabetes. Twenty Wistar rats were used. The rats were initially fed a CHOW diet, which is the standard balanced diet for rats, for 4 weeks. The rats were then divided into 2 groups of 10 where 1 group was fed CHOW and another was fed a high fat (HF) diet in order to induce obesity. The two groups were fed their respective diets for 18 weeks. Rats were weighed. Rats were placed in metabolic chambers and 24 hour urine samples were collected. Ketone levels were measured by Ketostix. Urine proteins were precipitated by acetone, quantified and separated on both the 1D SDS-PAGE and the 2D SDS-PAGE. Protein expression changes between CHOW and HF fed rats were determined and identified using MALDI-TOF mass spectrometry. Protein spots intensities increased and decreased between the CHOW and HF fed rats. Transducin (beta)-like 3 was identified as the only differentially expressed protein, which might serve as a potential biomarker for prediabetes.