Population genetic study of 10 short tandem repeat loci from 600 domestic dogs in Korea

Shared alleles and genetic structures in different Thai domestic cat breeds: the possible influence of common racial origins

Over hundreds of years, cats have been domesticated and selectively bred, resulting in numerous pedigreed breeds expedited by recent cat shows and breeding associations. Concerns have been raised about the limited breeding options and the genetic implications of inbreeding, indicating challenges in maintaining genetic diversity and accurate identification in purebred cats. In this study, genetic variability and structure were examined in 5 Thai domestic cat breeds using 15 microsatellite markers and mitochondrial DNA (mtDNA) D-loop sequencing. In total, 184 samples representing the Wichien Maat (WCM), Suphalak (SL), Khao-Manee (KM), Korat (KR), and Konja (KJ) breeds were analyzed. High genetic diversity (Ho and He > 0.5) was observed in all breeds, and mtDNA analysis revealed two primary haplogroups (A and B) that were shared among all domestic cat breeds in Thailand and globally. However, minor differences were observed between Thai domestic cat breeds based on clustering analyses, in which a distinct genetic structure was observed in the WCM breed. This suggests that allele fixation for distinctive morphological traits has occurred in Thai domestic cat breeds that emerged in isolated regions with shared racial origins. Analysis of relationships among individuals within the breed revealed high identification efficiency in Thai domestic cat breeds (P(ID)sibs < 10-4). Additionally, diverse and effective individual identification can be ensured by optimizing marker efficiency by using only nine loci. This comprehensive genetic characterization provides valuable insights into conservation strategies and breeding practices for Thai domestic cat breeds.

Development and validation of a novel 30-plex STR assay for canine individual identification and parentage testing

Domestic dogs are helpers in outdoor human work and companions for families; thus, individual canine identification and parentage testing are crucial in certain fields, including forensics and breeding programs. In this study, a six-dye fluorescent labeling multiplex amplification system containing 29 canine short tandem repeats (STRs) and the sex-determining marker DAmel was developed. The system was called the Tronfo Canine 30-plex STR Kit and was further validated according to the Scientific Working Group on DNA Analysis Methods and the Organization of Scientific Area Committees for Wildlife Forensics guidelines, including tests for PCR conditions, precision, species specificity, sensitivity, stability, repeatability and reproducibility, a population study, and a study of 16 paternity test cases. The results indicated that the novel canine STR assay was accurate, specific, reproducible, stable, and robust. Complete profiles were obtained with 31.25 pg of canine DNA. Additionally, 500 unrelated canine individuals were investigated using this novel system, and the combined power of discrimination and exclusion values were 0.999999999999999999 and 0.999996451039850, respectively. These results suggest that the Tronfo Canine 30-plex STR Kit is highly polymorphic, informative, and suitable for individual canine identification and parentage testing.

Optimizing Bangkaew dog breed identification using DNA technology

BACKGROUND

The Bangkaew dog is an indigenous dog breed in the Phitsanulok province of Thailand. This breed is recognized by the Fédération Cynologique Internationale (FCI), a global canine organization. The unique traits of the Bangkaew breed lead to purebred selection for breeding, while only their traits and pedigree from parental history are recorded. Determination of the risk of inbreeding depression and the origin of unknown DNA profiles is essential due to the challenges in predicting puppy characteristics, which are crucial for breed management and conservation.

OBJECTIVE

This study aimed to emphasize that current allelic frequency data for the Bangkaew dog breed must be considered for precise individual identification.

METHODS

Approximately 82 Bangkaew dogs from various Thai localities were studied using 15 microsatellite markers for genotypic monitoring and individual identification. Maternal genetic inheritance was assessed via mtDNA D-loop analysis.

RESULTS

The results revealed high genetic diversity in the Bangkaew breed, indicating low potential for inbreeding. We also found that using a 15 loci microsatellite panel was effective for the identification of Bangkaew dogs. The optimized 10 loci microsatellite genotyping panel developed in this study presents improved identification testing efficiency, promoting both time- and cost-effectiveness.

CONCLUSION

Analysis of microsatellite DNA markers in Bangkaew dogs using an optimized panel of 10 loci selected from 15 loci effectively facilitated individual identification. This approach not only enhances time and cost efficiency, but also provides accurate allelic frequency estimates, which are crucial for the realistic evaluation of DNA evidence.

Polymorphism analyses of 19 STRs in Labrador Retriever population from China and its heterozygosity comparisons with other retriever breeds

Pure breed dogs of Western origin are increasingly more popular in China as is a need to differentiate breeds and individual dogs for personal and forensic reasons. Research on genetic diversities of the canine population in China is rarely conducted. In this study, genetic distributions and forensic efficiencies of 19 canine STR loci in Labrador Retriever population from China were evaluated by using one available commercial canine kit in China. This panel was used to genetically define 214 Labrador Retrievers in China, as an example of one of the most important Western breeds and to compare them with Labrador Retrievers from America based on three overlapping STR loci. Moreover, genetic relationship analyses between Labrador Retriever population and two reference populations in America were performed. All 19 STR loci were polymorphic and conformed to Hardy-Weinberg equilibrium in the studied population. The STR panel was able to discern individual dogs with a high degree of accuracy. Breed-wide genetic heterozygosity comparisons based on present and published allele frequencies revealed that the studied population had the lower genetic heterozygosity than canine populations in America. Principal component analysis among Labrador Retriever population and other reference populations showed that the studied Labrador Retrievers were genetically close to the retriever breeds in America. Population genetic structure analyses among these canine breeds further revealed genetic differentiations between the studied Labrador Retriever population and other compared breeds. In conclusion, these STR loci had relatively high forensic values in Labrador Retriever population in China, which could be employed for individual identification and kinship testing.

The use of genetic markers to estimate relationships between dogs in the course of criminal investigations

OBJECTIVE

Attacks on humans by dogs in a pack, though uncommon, do happen, and result in severe, sometimes fatal, injuries. We describe the role that canine genetic markers played during the investigation of a fatal dog-pack attack involving a 50-year-old male truck driver in a parking lot in Tuscany (Italy). Using canine specific STR genetic markers, the local authorities, in the course of their investigations, reconstructed the genetic relationships between the dogs that caused the deadly aggression and other dogs belonging to the owner of the parking who, at the moment of the aggression, was located in another region of Italy.

RESULTS

From a Bayesian clustering algorithm, the most likely number of clusters was two. The average relatedness among the dogs responsible for the aggression was higher than the average relatedness among the other dogs or between the two groups. Taken together, all these results indicate that the two groups of dogs are clearly distinct. Genetic relationships showed that the two groups of dogs were not related. It was therefore unlikely that the murderous dogs belonged to the owner of the parking lot who, on grounds of this and additional evidence, was eventually acquitted.