Use this URL to cite or link to this record in EThOS:
Title: Applications of the random amplified polymorphic DNA (RAPD) technique in tilapia (Pisces cichlidae) : species, subspecies and sex identification
Author: Bardakci, F.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1995
Availability of Full Text:
Access from EThOS:
The RAPD reaction was optimised and factors affecting RAPD results were examined to obtain reproducible and reliable DNA markers for the tilapia genome. Homogeneity between RAPD samples during the preparation, amplification and electrophoresis is essential for obtaining reproducible RAPD fingerprint patterns. RAPD markers were used to discriminate between several commercially important species and subspecies of tilapia. The technique was efficient in revealing genetic variability both within and between populations. Phylogenetic relationships between these species and subspecies showed broad agreement with results from other studies. The technique was used to try to develop sex-linked RAPD markers in O. niloticus for individual sex identification. In an attempt to increase the efficiency of the technique, Bulk Segregant Analysis was initially used for three genotypic sexes (YY, XY and XX) of O. niloticus. As this approach did not produce reproducible sex-linked RAPD markers, individual DNA samples were also used. Discriminant function analysis based on the results for several primers allowed discrimination of the three genotypic sexes of O. niloticus. Three non-random short primers of repeat sequences were also tested in an attempt to search for sex-specific markers. One of these produced a RAPD-like fingerprint pattern but there were not polymorphisms between sexes. Although none of the individual primers tested produced reproducible and reliable RAPD markers, some primers gave polymorphism in some amplifications between genotypic sexes of O. niloticus. DNA from some of these marker bands was cloned and sequenced to make highly specific PCR primers. This experiment was carried out to detect genetic variation between sexes using direct sequencing, restriction fragment analysis and Single Strand Conformational Polymorphism analysis of these specific RAPD bands. None of these methods showed any difference between sexes for the RAPD bands examined. Amplification of these markers from different species of tilapia showed the potential and benefits, for diagnostic purposes, of amplification of single RAPD markers using these specific primers.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available