Forensic validation of a panel of 12 SNPs for identification of Mongolian wolf and dog.

Wolf (Canis lupus) is a species included in appendices of CITES and is often encountered in cases of alleged poaching and trafficking of their products. When such crimes are suspected, those involved may attempt to evade legal action by claiming that the animals involved are domestic dogs (C. l. familiaris). To respond effectively to such claims, law enforcement agencies require reliable and robust methods to distinguish wolves from dogs. Reported molecular genetic methods are either unreliable (mitogenome sequence based), or operationally cumbersome and require much DNA (un-multiplexed microsatellites), or financially expensive (genome wide SNP genotyping). We report on the validation of a panel of 12 ancestral informative single nucleotide polymorphism (SNP) markers for discriminating wolves from dogs. A SNaPshot multiplex genotyping system was developed for the panel, and 97 Mongolian wolves (C. l. chanco) and 108 domestic dogs were used for validation. Results showed this panel had high genotyping success (0.991), reproducibility (1.00) and origin assignment accuracy (0.97 ± 0.05 for dogs and 1.00 ± 0.03 for wolves). Species-specificity testing suggested strong tolerance to DNA contamination across species, except for Canidae. The minimum DNA required for reliable genotyping was 6.25 pg/µl. The method and established gene frequency database are available to support identification of wolves and dogs by law enforcement agencies.

[Comparative analysis on the transcriptomes of the prostates of muskrats at breeding stage and non-breeding stage].

The muskrat (Ondatra zibethicus L.) is a seasonal breeding animal. Adult male muskrat has a pair of scent glands between the muscle and skin above the urogenital tract, which secrete muskrat musk during the breeding stage. Compared with other rodents, the muskrat prostates and seminal vesicles are very well developed throughout the breeding stage. Studies have shown that intraperitoneal injection of muskrat musk can readily promote the development of the prostates and seminal vesicles in the male mice, suggesting a tight correlation between musk secretion and the development of the prostates and seminal vesicles in the muskrat. In this study, RNA-seq technology was used to analyze the gene expression patterns were further investigated by gene ontology (GO) analysis and KEGG pathway analysis. The results showed that 1629 genes were significantly and differentially expressed and were involved in a variety of signal transductions and energy metabolism pathways. The differential expression patterns of the OBP2 gene, and members of the Bcl-2 family and tumor necrosis factor receptor superfamily suggest that the prostate development in muskrat is controlled by a variety of molecular mechanisms; and the musk secreted by the muskrat scent glands might participate in the regulation of such developmental processes.

Individualization of tiger by using microsatellites.

In investigating criminal cases of poaching and smuggling involving tigers (Panthera tigris), the number of tiger individuals involved is critical for determining the penalty. Morphological methodologies do not often work because tiger parts do not possess the distinctive characteristics of the individual. Microsatellite DNAs have been proved a reliable marker for the individualization of animals. Seven microsatellite loci derived from domestic cat (Felis catus) were selected to individualize tigers, namely F41, F42, F146, Fca304, Fca391, Fca441 and Fca453. A reference population containing 37 unrelated tigers were used to investigate alleles, allelic frequencies, genotypes and genotype frequencies of each locus. Consequently, the data was used to assess the validity of the combination of seven loci for tiger individualization. All loci were polymorphic and easy to amplify. Three out of the seven loci were significantly departure from the Hardy-Weinberg Equilibrium (P < 0.05). Cumulative discrimination power (DP) calculated with observed genotype frequencies was 0.99999789. Match probability of an individual in the reference population with a random individual in seven loci ranged from 7.34 x 10(-9) to 2.77 x 10(-5). This suggests that combining the seven microsatellite loci provides desirable power to individualize tigers. The combination of seven loci was applied to a case of tiger bone smuggling. Genotypes of all samples were identical in all seven loci, and the P(M) of the evidence samples in the seven loci hit 5.63 x 10(-7), provided evidence that the bones belong to a single tiger.