Vol. 41 No. 4, 2002
Techniques to Identify Freshwater Eels: RFLP Analyses of PCR-amplified
DNA Fragments and Allele-specific PCR from Mitochondrial DNA
Yeong-Shin Lin1,2, Yu-Ping Poh2, Si-Min Lin2,3 and Chyng-Shyan Tzeng2,*
1Department of Biotechnology, National Chiao Tung University, Hsinchu, Taiwan 300
2Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan 300
Yeong-Shin Lin, Yu-Ping Poh, Si-Min Lin and Chyng-Shyan Tzeng (2002) Because of morphological ambiguity, traditional classification of freshwater eel elvers (of the genus Anguilla)
has always been difficult and unreliable. This study analyzes 2
mitochondrial genes viz., cytochrome b and 12S ribosomal RNA (rRNA)
genes from previous studies, to establish molecular standards for eel
identification. Prediction of restriction fragment length polymorphism
(RFLP) indicated that a combination of 3 enzyme results for cytochrome b
revealed good resolution power. We also selected 39 specific nucleotide
sites of the 2 genes at which the site is unique for individual
species: thus these can potentially be used for identification by
polymerase chain reaction (PCR). To verify the accuracy of our
predictions, we examined 58 specimens from 4 species by DpnII and HaeIII
digestions and by PCR amplification using species-specific primers.
Consistent with the putative mutation rates, more than 95% and 99% of
the specimens could be successfully identified by the RFLP and PCR
methods, respectively. The molecular techniques developed here can be
helpful in eel aquaculture and ecological studies.
Key words: PCR, RFLP, Identification, Anguilla, Elver.
*Correspondence: Tel: 886-3-5742765. Fax: 886-3-5715934. E-mail: email@example.com