II.3. BRASSICA CROPS (BRASSICA SPP.) – 247
TILLING technique
The technique of TILLING (targeted induced local lesions in genomes) can be used to
identify a series of mutations (alleles) in a target gene by heteroduplex analysis
(McCallum et al., 2000). This method combines a standard technique of mutagenesis with
a chemical mutagen such as ethyl methanesulfonate (EMS),^6 with a sensitive DNA
screening technique that identifies single-base mutations (also called point mutations) in a
target gene.
This technique is available from the Canadian TILLING Initiative (CAN-TILL) at the
University of British Columbia on a fee-for-service basis. The CAN-TILL facility is
currently developing a large-scale mutant population for Brassica napus as part of a
Genome Canada project and has completed projects on B. oleracea and Arabidopsis
thaliana. B. rapa TILLING services are available from RevGenUK in the United
Kingdom (John Innes Centre).
Gene transfer
The transfer of a gene(s) from an unrelated species is undertaken only when the
desired trait cannot be found or induced by traditional methods. Because of the huge costs
and time required to comply with multiple regulations in multiple countries, only those
traits that have a potentially large and valuable market are considered for commercial
exploitation.
Notes
- The authority for the scientific names used in this chapter is given in Tables 3.2
and 3.3. The nomenclatural authority for genus and species names not listed in the
tables will be included in the text where they first appear. - Autosyndesis is defined as the pairing of completely or partially homologous
chromosomes during prophase of the first meiotic division. - This section is drawn from Wang, Guan and Zhang (2007).
- This section is drawn from Downey, Klaasen and Stringham (1980); Dickson and
Wallace (1986).
5 This citation has been added for update in January 2016.
- Ethyl methanesulfonate (EMS): http://en.wikipedia.org/wiki/Ethyl_methanesulfonate.