What is Cytogenetics?

Cytogenetics is one of the oldest branches of genetics. The ability to analyse banded chromosomes, a specialist task that was introduced in the 1970s, increased the range of genetic disorders that could be identified.

Cytotaxonomy plays a major role in the identification of hybrid species. With more than 80% of all plant species having a hybrid origin, the importance of cytotaxonomy is emphasised. The implementation of techniques like fluorescent in situ hybridisation (FISH) – whereby a DNA sequence is used to indicate the position of a gene on a chromosome – and genome in situ hybridisation (GISH) – which is used to trace the origin of chromosomes in hybrid species – support the importance of molecular cytogenetics and gene mapping.

What is Molecular Systematics?

Molecular systematics is one of the fastest growing disciplines in the world and numerous international journals are dedicated to publishing studies that entail molecular systematics.

In a molecular systematic study, molecular data such as DNA sequences are used to reconstruct the evolutionary history, relationships, and genetic diversity of organisms. Additional data such as taxonomy, biogeographical, cytotaxonomical, medicinal, and nutritional data can be included to complete the evolutionary puzzle of an organism. A popular example of a molecular systematic study is the use of the mitochondrial DNA to determine the female common ancestor and evolutionary history of modern humans. Our research focuses mainly on the evolution of ornamental and medicinal plant species, although molecular systematics has a broad application on all types of organisms such as viruses, fungi, insects, and animals.

What is DNA-barcoding?

DNA-barcoding is basically a technique used to identify unknown species of plants, animals or even microorganisms. For instance, DNA-barcodes can be used in forensic studies to identify unknown samples that are traded illegally (e.g., smuggled plants, poached animals, etc), fossil samples isolated from caves and contamination in the food industry. To identify an unknown sample, DNA is extracted from the tissue, a specific region of the DNA is amplified and sequenced. The obtained sequence will then be compared to a reference sequence database and the organism is identified.

Our research focuses mainly on the development and expansion of the Barcode of Life Data Systems (BOLD) supported by the International Barcode of Life (iBOL) project. The current contribution of the Department of Genetics focuses on adding DNA-barcodes of ornamental and medicinal plant species. Another project is in the pipeline to add DNA barcodes of Penicillium species found at milling companies in South Africa. Future contributions will also include the addition of DNA-barcodes of various insect and animal species to the BOLD database.

Cytogenetics, Molecular Systematics and DNA-barcoding in the Department of Genetics

Research in these fields is conducted by Prof JJ Spies and Ms P Spies, together with the following postgraduate students:

PhD

  • Ms R (Riana) Kleynhans: 'Development of Lachenalia cultivars in South Africa'
  • Ms P (Paula) Spies: 'A comparison of the efficiency of DNA barcoding regions in a small and a large genus'

MSc

  • Mr B (Bulelani) Sizani: 'The phylogenetic relationship in the Lachenalia pusilla group'
  • Ms M (Marli) Watson: 'Phylogeographical study of Clivia in Pondoland and adjacent areas'
  • Ms A (Anrie) de Vos: 'The efficiency of DNA-barcoding in the species delimitation of Lachenalia'
  • Mr R (Ryno) Schoeman: 'Penicillium species associated with the maize milling industry in South Africa'
  • Ms L (Lari) le Roux: 'The genetic basis of leaf variegation in Clivia'

FACULTY CONTACT

Faculty Manager: Ms Lee-Ann Frazenburg
T: +27 51 401 3199
E: damonsle@ufs.ac.za

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T: +27 51 401 2531
E: lottere@ufs.ac.za

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