Optimization of polymerase chain reaction for the identification of Roe deer, Saiga, and Siberian stag living in Kazakhstan

Background and Aim:

One of the reasons for the decline in the number of wild species of artiodactyls is poaching and the illegal trading of animal products. Molecular genetic identification of animals from a biological sample effectively proves poaching cases and illegal trade of animal products. This study aimed to develop a polymerase chain reaction (PCR) test that allows for species identification of artiodactyl animals that are most often subject to poaching.

Materials and Methods:

Genomic DNA was extracted from meat and blood samples of animals killed by poachers using commercial kits. Three pairs of primers were designed and used to amplify the cytochrome b gene fragment of Roe deer, Saiga antelope, and Siberian stag.

Results:

The proposed protocol allows amplification of specific PCR products of 542 bp with Roe deer DNA, 587 bp with Saiga DNA, and 525 bp with Siberian stag DNA. Specificity analysis showed no cross activity with DNA from other animal species. The detection limit of PCR ranged from 15.6 pg to 1.9 pg of DNA in 25 mL of the reaction mixture.

Conclusion:

Sequencing the amplified products and subsequent comparison with the corresponding reference sequence showed a similarity ranging from 99.99% to 100%. The PCR based on the developed primers demonstrated high sensitivity and specificity when using DNA from homogeneous and heterogeneous animals.

Polychlorinated biphenyl toxicity in the thyroid gland of wild ungulates: an in vitro model

Polychlorinated biphenyls (PCBs) are carcinogens causing endocrine disruption. While production of PCBs is now banned, wildlife exposure still occurs due to environmental contamination. We investigated thyroid toxicity in wild ungulates using three-dimensional primary thyrocyte cultures exposed to PCB 138 for 24, 48, and 72 h at concentrations ranging within 0–3000 ng/ml. Thyrocyte viability ranged within 78.71–118.34%, 98.14–104.45%, and 84.16–106.70% in fallow deer-, mouflon-, and roe deer-derived cells, respectively. Viability decreased significantly in fallow deer (P = 0.012) and roe deer (P = 0.002) thyrocytes exposed for 48 h at 30 ng/ml. While cytotoxicity ranged within 2.36–16.37%, 3.19–9.85%, and 2.76–11.21% in fallow deer, mouflon, and roe deer, respectively, only roe deer displayed significantly higher cytotoxicity at a 3 ng/ml exposure (P < 0.05) and lower cytotoxicity at 30 ng/ml (P < 0.01). Exposure to 30 ng/ml for 24 and 48 h induced reactive oxygen species in fallow deer. Iodide uptake at 30 ng/ml exposure increased after 24 h in fallow and roe deer, but showed a significant drop after 48 and 72 h in fallow deer, mouflon, and roe deer. Thyroxine T4 release at 30 ng/ml exposure decreased significantly after 48 and 72 h; 24, 48 and 72 h; and 48 h in fallow deer, mouflon, and roe deer, respectively. Our findings indicate time- and species-dependent effects of PCB on performance and thyrocyte function. Use of cell culture models reduces the number of experimental specimens, increases test species welfare and replaces whole organisms with specific target cells.

Development and validation of a rapid kit for authenticity of murine meat in meat products with a species-specific PCR assay

Adulteration of meat products with murine meat poses a huge threat to consumer health and leads to serious disruption in food markets. Species authentication of murine meat is still technically challenging. We, therefore, developed a species-specific PCR kit consisting of murine meat DNA extraction, PCR reaction and identifying systems. We designed novel universal primers targeting highly conserved region on mitochondrial cytochrome b gene (cyt b) from four murines (lab rats, lab mice, wild rat and wild mice), as well as specific primers for meat from four widely consumed animal species, cattle, sheep, duck and donkey. Simultaneously, pasmid inserted specific cyt b fragment was cloned and used as the internal positve control in the kit. The kit parameters of specificity, sensitivity, stability and validity were determined using mimic counterfeiting meatball. The specificity of the DNA detection kit was 100% in authentication of the four fraudulent meats of cattle, sheep, duck and donkey mixed murine meat. The minimum detection limit of the sample DNA was 0.1 μg. The kit, which had freeze-thawed up to 20 times and stored for 1 year, also was powerful in detecting an amount of 0.1 mg in artificial counterfeited cattle, sheep, duck and donkey meat products. The murine-species DNA detection kit proposed in this study has proved to be a simple, accurate and effective assay, and can be applied to the identification of murine meat traces in common edible meat, to ensure the realisable implementation of meat product market supervision.