Eels: Multi-gene DNA barcode species identification method.

China is a large export country of eel culture and processing. In order to safeguard the interests of enterprises and consumers and the normal market order, the
should, at the request of enterprises and law enforcement agencies, establish the precise identification method of eel species, which has important practical significance for China's eel farming industry and processing export trade. In order to safeguard the interests of enterprises and consumers and the normal market order, the
should, at the request of enterprises and law enforcement agencies, establish the precise identification method of eel species, which has important practical significance for China's eel farming industry and processing export trade.
polymerase chain reaction (PCR) amplification technology has been studied and applied in the identification of fish species composition in food, and the application in eel is mainly based on PCR random amplification DNA genetic diversity analysis and species identification research, but in inspection and quarantine, the practice of application, lack of stability and accuracy.
rare lying at home and abroad using multi-gene DNA barcodes for eel species identification.
Chen Wenxuan, Yu Biying and Mu Yu, from the Inspection and Quarantine Technology Center of Fujian Entry-Exit Inspection and Quarantine Bureau, extended the 16S rRNA gene on the basis of DNA barcodes (243 bp) based on DNA fragments of the 16S rRNA gene part. Some of the DNA fragments were 262 bp and the standard DNA barcodes for multi-gene dna, in addition to cyt b and COI genes, established a multi-gene DNA barcode species identification method for six species of American eel, European eel, Japanese eel, Mozambican eel, flower eel, pacific two-color eel.
in order to safeguard the interests of enterprises and consumers as well as the normal market order, avoid trade barriers, provide technical protection, China's eel breeding industry and processing export of foreign trade has important practical significance.
16S rRNA, Cyt b, COI. Gene fragment PCR primer screening and product sequence analysis used 3 universal primers for 3 genes (16S rRNA, Cyt b, COI.) dna for PCR amplification, PCR products two-way sequencing, 6 eels each obtained 3 16S rDNA, Cyt b, COI.COI. The dna sequence of the gene part, the length of the fragment snippets are 638-643, 464-466, 705-707 bp, and the BLAST ratio was compared to the corresponding gene sequences of American eels, European eels, Japanese eels, Mozambican eels, flower eels and Pacific eels in the database.
based on the homologous comparison of 6 sequences of each gene, excluding the absence of bases in the sequence and the non-difference interval, selected the same-origin fragments of each species sequence for the design of new primers.
the screening of the standard sequence of DNA barcodes and the self-designed 3 pairs of primers 16S rDNA 504, Cyt b 400, COI.609 to 6 eel species for PCR amplification and sequencing, screening and intercepting 6 eel-base sequences from each sequence with low cogenicity , species-specific, no base missing or inserted fragments, as 6 eel 16S rRNA, Cyt b, COI.3 gene standard DNA bar code, fragment length is 262, 280, 300 bp, the same sequence of the first and last subline section of the 8 bases for the intercept purpose of the lead.
in addition to The Pacific two-color eel, the DNA sequence matching (homogenous) rate of Japanese eel, American eel, European eel, Mozambican eel and flower eel was 99% to 100% except in a few cases.
in 16S rDNA barcode base sequence comparison, the DNA barcode of the European eel sample is compared in the GenBank database with a homologous rate of 100% for an A. rostrata (KJ564271.1) fragment, possibly a misname when submitted by the sequence provider.
sample of Mozambican eel Cyt b (280 bp) DNA bar code comparison, appears with an Indian Ocean bicolor eel (AB021780.1) fragment with a homologous rate of 100%, and may also be the sequence provider submitted the wrong seed name.
, in comparison with the GenBank database, three gene DNA barcodes of Pacific bi-color eels in the test sample scored very close to the indian Ocean two-color eel species, and the 16S rDNA barcode base sequence matched at a homologous rate of 100% Of the first 100 clips, the first six are Pacific two-color eels, followed by 82 Indian Ocean bi-colored eels, and 12 of the 12 with a homologous rate of 99% are also Indian Ocean bi-colored eels; in Cyt b (280 bp)) DNA bar code comparison, the same-origin rate of 100% of the 16 fragments are Pacific two-color eels, the same source rate of 99% of 57, the Pacific two-color eel accounted for 23, the Indian Ocean two-color eel accounted for 34, the remaining homologous Twenty-seven of the 98 per cent were also Indian Ocean bicolored eels, and in the sample Pacific bi-colored eel's COI. (300 bp) DNA barcode sequence was found in comparison with the GenBank database, the homologous rate of 100% was only 1 fragment (A. Bicolorpacifica, AP007237.3), the other 99 are same-origin 98% Indian Ocean bi-color eels. the establishment and application of the DNA bar code identification method of
DNA bar code are 100% homogenous with the corresponding DNA standard bar code of 3 genes in each sample.
, 8 samples were identified as American eels, 5 samples were European eels, 3 samples were Japanese eels, 4 samples were Mozambican eels, 5 samples were flower eels and 5 samples were Pacific two-color eels.
samples are based on the comparison of 3 genetic DNA barcodes, conforming to the homologous rate index, and the species identification results match each other, thus accurately distinguishing the species to which the sample belongs.
the method is stable, accurate and easy to operate, and can be applied to the identification of 6 eel species, which is worth promoting.
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