Application of Specific Fragment Length Polymorphism of Algae rDNA in Identification of Drowning Cases / 法医学杂志

OBJECTIVES@#To identify the drop-off location of victims in drowning cases, and confirm whether it is a fatal drowning or the victim is thrown into the water after death by detecting part of 5.8S sequence and second internal transcribed spacer （ITS2） （5.8S+ITS2） of diatom rDNA in water and organs.@*METHODS@#Two cases identified by diatom examination, which received by Nanjing Municipal Public Security Bureau Forensic Center, were taken as the research objects. The difference of the population structure of algae in water and human tissue was analysed by length polymorphism of 5.8S+ITS2 marker.@*RESULTS@#In case 1, similar species of diatom were detected from victim's lung and liver tissues and the water sample. Two kinds of DNA fragments with length of 330 bp and 376 bp were detected from victim's lung tissue and the water sample using 5.8S+ITS2 marker, which could confirm the victim was drowning before death. In case 2, there was no diatom found in victim's lung and liver tissues. Only one kind of DNA fragment with length of 331 bp and low relative fluorescence unit （RFU） was obtained from victim's lung tissue using 5.8S+ITS2 marker, thus the victim was thrown into the water after death.@*CONCLUSIONS@#The experimental results of the two cases in present study are consistent with the actual facts and the result of the diatom microscopic examination. The difference of population structure of specific microorganism in water and human tissue can be detected by 5.8S+ITS2 marker, which can help to identify the drop-off location of victims in drowning cases, and confirm whether it is a fatal drowning or the victim is thrown into the water after death.

Genetic compatibility between Anopheles lesteri from Korea and Anopheles paraliae from Thailand

To assess differentiation and relationships between Anopheles lesteri and Anopheles paraliae we established three and five iso-female lines of An. lesteri from Korea and An. paraliae from Thailand, respectively. These isolines were used to investigate the genetic relationships between the two taxa by crossing experiments and by comparing DNA sequences of ribosomal DNA second internal transcribed spacer (ITS2) and mitochondrial DNA cytochrome c oxidase subunit I (COI) and subunit II (COII). Results of reciprocal and F1-hybrid crosses between An. lesteri and An. paraliae indicated that they were compatible genetically producing viable progenies and complete synaptic salivary gland polytene chromosomes without inversion loops in all chromosome arms. The pairwise genetic distances of ITS2, COI and COII between these morphological species were 0.040, 0.007-0.017 and 0.008-0.011, respectively. The specific species status of An. paraliae in Thailand and/or other parts of the continent are discussed.

INVESTIGATION OF THE SPECIESSTATUSOF ANOPHELES DIRUS( DIPTERA:CULICIDAE) FROM HAINAN PROVINCE USING r DNA / 中国寄生虫学与寄生虫病杂志

AIM:To ascertain the species status of the Anopheles dirus from Hainan Province,Chi- na.METHODS:The nucleotide sequence of the second internal transcribed spacer(ITS2 ) of PCR- amplified r DNA was determined for the An.dirusspecimens which included 2 individu- als of the species A colony (AFRIMS) from Thailand and 5 individuals from Hainan Province.RESUL TS:A841 bp fragment was amplified from single mosquito.The fragment included the ITS2 and small portions of flanking 5 .8S (96 bp) and 2 8S (2 9bp) genes.The ITS2 was71 6 bp in length,the sequence was identical for all7individuals from both Hainan Province and Thailand.No evidence of intraspecies or intrapopulation variation was detected in the ITS2 and flanking regions.CONCL USION:The result suggests the existence of An. dirus A in Hainan Province,which was in agreement with previous studies from cytogenetic analysis and egg characteristics determined by scanning electron microscopy.