RESUMO
Objective To apply DNA barcoding technology for exploring its taxonomic status and differences in the molecular biology of Cricetulus barabensis in Shaanxi Province.Methods Sixty-five samples of Cricetulus barabensis were collected from Dingbian,Jingbian Counties in northern of Shaanxi and Dali County in Guanzhong plain (Dingbian 58 samples,Jingbian 2 samples,and Dali 5 samples).According to the mitochondrial cytochrome C oxidase subunit I gene (CO I) sequence,the genetic distance was calculated and Neighbor-Joining tree was constructed.Results The genetic distance between two samples (13.16,13.21) and other 56 samples of Dingbian was 9.2％-10.0％.The genetic distance between the 56 samples of Dingbian and Jingbian was less than 1％ and Dali was 7.2％-8.3％;the average intraspecific genetic distance of Jingbian and Dali was less than 1％.The Neighbor-Joining tree showed that all the Cricetulus barabensis samples from the three counties were separated into two large branches.The samples of 13.16,13.21 from Dingbian together were classified into a class and the rest of the samples into another separate branch.At the same time,other samples from Dingbian except 13.16,13.21 and Jingbian were distributed in a small branch,and Dali samples were occupied another small branch.Conclusion Using the DNA barcoding technology,we have determined three subspecies of Cricetulus barabensis in Shaanxi Province,Dingbian has two kinds and Dali has a different subspecies.
RESUMO
Objective To apply the DNA barcoding technology for identification on host animal and to establish the host animal DNA bar code database on natural foci of plague in Shaanxi.Methods 139 host animals belonging to 3 orders,6 families and 12 genera and 62 residues belonging to 7 species from 8 different parts of the province,were detected.DNA barcoding technology was used to analyze the DNA CO Ⅰ gene sequence on the natural foci of plague in Dingbian county.Results The intra-specific genetic distance was less than 2％ while the inter-specific distance ranged from 8.9％ to 15.1％.Fourteen major clusters were apparently showed on a Neighbor-Joining tree.Residue samples could be detected regarding the objective gene.Alashan ground squirrel was previously noticed to carry 14 major clusters,which were previously mistakenly named as Citellus dauricus in Dingbian county.Conclusion DNA barcoding technology could overcome the shortcomings caused by the morphological identification so could be used to identify the host animal and residues in the natural focus of plague.
RESUMO
Objective To identify rodent residues using DNA barcoding technology in plague areas of Shaanxi and to analyze the feasibility of DNA barcoding method.Methods DNA extraction,PCR,electrophoresis and sequence determination and alignment were used to determine the cytochrome C oxidase Ⅰ (COI) gene sequence from 62 residues of 7 species identified by morphology in 8 different parts.COI gene sequence was analyzed using BLAST software of American National Center for Biotechnology Information (NCBI) for sequence homology comparison and the phylogenetic tree was constructed by using the neighbor joining(NJ)method of COI gene sequence.Results In addition to the hair,CO I genes of the feet,the tail,the fur,the muscle,the ribs,the ear,and the eye were amplified,respectively,and the size of amplified fragment was similar to the size of the product with an expected fragment(700 bp),and the fragment was a single band.COI genes of 59 residue specimen were obtained by DNA sequencing and there were high degree of homologies between CO I gene sequences of Meriones unguiculatus,Cricetulus barabensis,Meriones meridianus,Dipus sagitta,Phodopus roborovskii,Rattus norvegicus and Allactaga sibirica and their corresponding host genes in NCBI(99.0％,98.1％,99.8％,98.9％,99.5％,99.1％,98.3％).NJ method showed that 7 NJ phylogenetic trees were constructed with COI sequence of 59 species residues.The CO I sequences of same rodent with different residues were clustered into one group.Condusion DNA barcoding technology can identify host animal residues in plague areas,and the identification results are reliable.