ABSTRACT
Objective To illustrate more accurately the feasibility of DNA barcode technology in species identification in different geographical areas.Methods Four plague host animals were selected from three plague natural foci in Inner Mongolia for DNA barcode comparison,GC base content,codon preference and genetic distance calculation,and a phylogenetic tree was constructed.Results Compared between different foci of A llactaga sibirica,the difference of base content was statistically significant (F =5.34,P ＜ 0.05);the variation of Meriones unguiculatus focus Allactaga sibirica base content was larger,and compared with other foci Allactaga sibirica,the difference was statistically significant (all P ＜ 0.05).Different foci between one species rarely exist in codon sites.The genetic distance of intraspecific was less than 1％,and the genetic distance of interspecific was more than 18％.Conclusions DNA barcode of each species is specific,with no interspecific species sharing,and does not change with geographical position.Molecular identification of plague host animal is effective by DNA barcode.
ABSTRACT
Objective To determine a method for amplification of cytochrome C oxidase subunit Ⅰ (CO Ⅰ) gene of Brandt's vole.Methods 发he Brandt's Voles were captured in Abagaqi Xilingol League Inner Mongolia,and DNA was extracted from liver tissue.CO Ⅰ gene was amplified by nested PCR and sequenced afterwards.Results A band of 657 bp and 1 132 bp was amplified by internal and external PCR primers,respectively,which were consistent with expected sizes.A total of 12 segments of Brandt's Vole CO Ⅰ gene sequences were amplified by PCR and verified by sequencing.一he sequence number was KF182196-KF182207 in GenBank.After gene sequence alignment of the 12 CO Ⅰ gene sequences,it was found that the similarity was 100％,and no base mutation.Conclusion CO Ⅰ gene of Brandt's Vole could be amplified by nested PCR without pseudo gene.
ABSTRACT
Objective To study a rapid method for determination of trace formaldehyde in drinking water by oscilloscopic polarography.Methods In the base solution of0.01mol/L H 3 PO 4 ,the reaction product of formaldehyde and phenylhydrazine hydrochloride on the drop mercury electrode revealed a sensitive second order derivative polarographic wave at a pick electric potential-0.76V(VS?SCE).The optimum conditions and interference by other coexisting ions were analyzed.Results The de-tection limit,linear range,recovery rate,relative standard deviation(RSD)of the method were0.002mg /L,0.005-0.25mg /L,94.0%-103.0%,and0.05).Conclusion The method was simple,rapid,sensitive and highly specific.The analytical speed was about 50-60samples /h,which was suitable for the determination of trace formaldehyde in drinking water.