The assessment of the efficacy of STRs panels recommended by the ISAG for canine pedigrees analysis for forensic casework

Canine DNA is widely used in forensic investigations, particularly in dog attacks cases on humans. Nowadays, STR markers are employed worldwide in forensic laboratories to test human and animal genotypes. In the study we analysed the effectiveness of panel – 18 STR as previously recommended by ISAG and the same panel with three additional markers – 21 STR, which has been recommended by ISAG as the core panel for dog identification since 2016. We calculated the PD, PID for these sets of panels and estimated RMP based on the DNA profile obtained during an investigation of a woman bitten by a dog. The high combined CPD value for 18 and 21 STRs showed values close to 1.0. The CPID value for theses panels was 5.2 × 10−10 to 6.4 × 10−14. Statistical analysis estimated the random DNA match, in the case of the woman bitten by a dog, with a probability of 4.3×1019 and 2.8×1022, using 18 and 21 STR panels respectively, and that the canine DNA profile from the crime scene originated from the suspected dog and not from another random dog. Our results show that both STR panels can be used effectively for individual identification and forensic casework.

Development of a multiplex PCR short tandem repeat typing scheme for Candida krusei

Candida krusei is a human pathogenic yeast that can cause candidemia with the lowest 90-day survival rate in comparison to other Candida species. Infections occur frequently in immunocompromised patients and several C. krusei outbreaks in health care facilities have been described. Here, we developed a short tandem repeat (STR) typing scheme for C. krusei to allow for fast and cost-effective genotyping of an outbreak and compared identified relatedness of ten isolates to SNP calling from whole-genome sequencing (WGS). From a selection of 14 novel STR markers, six were used to develop two multiplex PCRs. Additionally, three previously reported markers were selected for a third multiplex PCR. In total, 119 C. krusei isolates were typed using these nine markers and 79 different genotypes were found. STR typing correlated well with WGS SNP typing, as isolates with the same STR genotype varied by 8 and 19 SNPs, while isolates that differed in all STR markers varied at least tens of thousands of SNPs. The STR typing assay was found to be specific for C. krusei , stable in 100 subcloned generations, and comparable to SNP calling by WGS. In summary, this newly developed C. krusei STR typing scheme is a fast, reliable, easy-to-interpret and cost-effective method compared to other typing methods. Moreover, the two newly developed multiplexes showed the same discriminatory power as all nine markers combined, indicating that multiplexes M3-1 and M9 are sufficient to type C. krusei .

Paleogenetic Analysis of the Residents from the Moscow Kremlin’s Podol (Lower Area) of the 14th Century (According to the Materials of Excavations in the Taynitsky Garden)

Introduction. The article presents the results of paleogenetic studies of medieval human remains of three people found in a closed archaeological complex (building 32) revealed during the excavations in 2007 in the Taynitsky Garden of the Moscow Kremlin (supervisor of excavations: N.A. Makarov). Previous studies on the dating of the complex links it to the devastation of Moscow by the troops of Tokhtamysh Khan in August 1382. The archaeological layer was formed at a time as a result of a fire and contained the remains of two adults and a 3-4 year old child who remained unburied. The aim of this work was the genetic study of the ancient DNA of the remains of people who died in the 14th century, clarification of their gender, determination of kinship and presumptive origin. Material and methods. For genetic examination, teeth were selected (permanent for adults, primary for a child). The laboratory research algorithm included a set of measures to protect archaeological DNA from contamination, sample preparation and extraction of DNA from dental remains, analysis of STR markers of the Y chromosome in males, analysis of ALU markers of autosomal chromosomes, targeted NGS sequencing of hyper-variable segments of mitochondrial DNA. Results and conclusion. Using the methods of molecular genetic research, it was possible to confirm that a man, a young woman and a child (boy) died in the fire. Based on the analysis of autosomal markers, with a high degree of probability (99.9%), a close biological relationship between a woman and a child (mother-son) was revealed. The man was not a relative of either the woman or the child. The mtDNA haplogroups and STR markers of the male specific Y chromosome identified in all three individuals are generally characteristic of the Slavic population of modern Europe. The mt haplogroup J1c, found in mother and child, is now most characteristic of the inhabitants of Europe. The man has a mitochondrial haplogroup K2, which is found mainly in Northwestern Europe.

PSVIII-2 Genetic diversity analysis of hybrid Karachaev goats (Capra hircus) population using microsatellite marker data

The Karachaev goat is an indigenous breed that possesses unique features including significantly less fat deposition in the body compared to sheep and cattle, ability to graze at an altitude of up to 1200 meters and to produce fertile hybrids with wild relatives. To understand the genetic diversity and population structure of hybrids between domestic Karachaev goats (Capra hircus) and The West Caucasian tur (Capra caucasica) 143 individuals were analyzed using 10 microsatellites panel. Sample were analyzed according to the manufacturer’s recommendations on an automatic sequencer, ABI 3130XL genetic analyzer (Applied Biosystems). Genetic diversity was calculated using GenAlEx 6.503 software. Genotyping of ten microsatellite loci in hybrid forms of Karachaev goats and turs detected 106 alleles in total. Na values ranged from five (INR063) to seventeen (SRCRSO008), averaging 10.6 alleles per locus across the 10 loci. All loci were polymorphic. The average number of alleles was 10.6 alleles per locus. This is higher than the similar indicator obtained by Kharzinova et al. (2019) in populations of Soviet wool, Tajik wool, Orenburg downy, Alpine and Zaanen dairy breeds of goats, studied using the panel of same 10 STR-markers (9.3 loci). Other key indexes of genetic diversity could be found in table 1. The values of the coefficient FIS suggest the absence of related mating in the herd. Information on genotypic variability of Karachaev goats hybrid forms obtained here will contribute into the breeding programs improvement and to preservation of existing native breeds.