A new recombined porcine reproductive and respiratory syndrome virus virulent strain in China

Porcine reproductive and respiratory syndrome (PRRS) is one of the most important swine diseases worldwide. In the present study, a new virulent strain of PRRS virus (PRRSV), GDsg, was isolated in Guangdong province, China, and caused high fever, high morbidity, and high mortality in sows and piglets. The genome of this new strain was 15,413 nucleotides (nt) long, and comparative analysis revealed that GDsg shared 82.4% to 94% identity with type 2 PRRSV strains, but only 61.5% identity with type 1 PRRSV Lelystad virus strain. Phylogenetic analysis indicated that type 2 PRRSV isolates include five subgenotypes (I, II, III, IV, and V), which are represented by NADC30, VR-2332, GM2, CH-1a, and HuN4, respectively. Moreover, GDsg belongs to a newly emerging type 2 PRRSV subgenotype III. More interestingly, the newly isolated GDsg strain has multiple discontinuous nt deletions, 131 (19 + 18 + 94) at position 1404–1540 and a 107 nt insertion in the NSP2 region. Most importantly, the GDsg strain was identified as a virus recombined between low pathogenic field strain QYYZ and vaccine strain JXA1-P80. In conclusion, a new independent subgenotype and recombinant PRRSV strain has emerged in China and could be a new threat to the swine industry of China.

Relationship between CO II gene of mtDNA of Lucilia sericata and latitude interval / 法医学杂志

OBJECTIVE@#To deduce the region that the geographical species of Lucilia sericata come from and determine the scene of crime (SOC) based on the gene analysis of mtDNA CO II.@*METHODS@#A 635 bp region for CO II of 4 Lucilia sericata (belong to 2 geographical species) were collected and sequenced, compared with the data of GenBank. A neighbour-joining tree with the Tamura and Nei model was constructed by MEGA2.1 package. The number of inherit intervals of inner-species were analyzes by Kimura's two-parameter model and used for construction the relationships between hereditary and latitude interval by SPSS10.5 soft.@*RESULTS@#It showed that they had the relationships between inherit and latitude interval for the 8 geographical species of Lucilia sericata for CO II.@*CONCLUSION@#This method can be the evidence deducing the region that the geographical species of Lucilia sericata come from and further to determine the scene of crime (SOC).

Forensic applications of the sequencing of mitochondrial DNA cytochrome oxidase subunit I gene for sarcosaphagous flies (Diptera) in Huhhot and Dunhuang district / 法医学杂志

OBJECTIVE@#To solve the problems of identification of Sarcosaphagous flies and their larvae, pupas and eggs.@*METHODS@#Sarcosaphagous Flies (Diptera) Samples were collected on the corpses of rabbits in the Huhhot district and a pig in the Dunhuang district. A 278bp region in the cytochrome oxidase subunit I (CO I) gene in mtDNA was analysed by DNA sequencing, A neighbour-joining tree using the Tamura and Nei model of nucleotide substitution was also constructed using the MEGA2.1 package.@*RESULTS@#A 278 base pairs region of the gene for CO I encoding region of mtDNA of above all samples was showed less than 1% sequence divergence within species and about 3% divergence between species.@*CONCLUSION@#It is an effective, easy and accurate method to be used for identification of these Sarcosaphagous Flies (Diptera) to species group by sequencing the 278 base pairs region of the CO I encoding gene of mtDNA.

The study of the major sarcosaphagous flies in Hohhot / 法医学杂志

OBJECTIVE@#In order to determine the major species of sarcosaphagous flies and their regular activity on carcass in Hohhot district.@*METHODS@#Six rabbits were killed and placed outdoors at different time from July to October in Hohhot district. Some species of sarcosaphagous flies that appeared the cadavers were observed and identified.@*RESULTS@#It showed that there are 10 main spieces belonging to 3 families and 8 genera were from Diptera, including Musa domestica domestica Linnaeus, Musa domestica vicina Maequart, Ophyra capensis (Wiedemann), Hydrotaea armipes (Fall.), Muscina stabulans (Fall.) from Museidae; Lucilia sericata (Meigen), Chrysomya megacephala (Fabricius), Lucilia cuprina (Wiedemann) from Calliphoridae; Boettcherisca peregrina (Robineau-Desvoiy), Parascarcophaga crassipalpis (Maequart) from Sacrophagidae. Besides, it showed obvious regulations that different species of sarcosaphagous flies appeared on carcass at different postmortem interval and the first part of carcass that sarcosaphagous flies appeared on.@*CONCLUSION@#It may be useful for estimating postmortem interval in Hohhot district.

A study of quadriplex PCR with chimeric primers for short tandem repeats loci / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a simplified method of multiplex PCR based on chimeric primers for STR loci.</p><p><b>METHODS</b>A set of chimeric primers and universal primers were designed to carry out a multiplex PCR for amplifying four short tandem repeats(STR) loci. Then the amplified STR loci were detected by polyacrylamide gel electrophoresis and the gels were sliverstained.</p><p><b>RESULTS</b>A quadriplex STR system was developed on the basis of both chimeric and universal primers.</p><p><b>CONCLUSION</b>The STR multiplex PCR based on both chimeric and universal primers hss been achieved readily and reproducibly by simple adjustment of the individual primer concentrations. The use of chimeric primers provides a method for primer design that eliminates the multiple optimization steps involved in developing the multiplex PCR.</p>