Comparison of prediction accuracy for genomic estimated breeding value using the reference pig population of single-breed and admixed-breed.

This study was performed to increase the accuracy of genomic estimated breeding value (GEBV) predictions for domestic pigs using single-breed and admixed reference populations (single-breed of Berkshire pigs [BS] with cross breed of Korean native pigs and Landrace pigs [CB]). The principal component analysis (PCA), linkage disequilibrium (LD), and genome-wide association study (GWAS) were performed to analyze the population structure prior to genomic prediction. Reference and test population data sets were randomly sampled 10 times each and precision accuracy was analyzed according to the size of the reference population (100, 200, 300, or 400 animals). For the BS population, prediction accuracy was higher for all economically important traits with larger reference population size. Prediction accuracy was ranged from -0.05 to 0.003, for all traits except carcass weight (CWT), when CB was used as the reference population and BS as the test. The accuracy of CB for backfat thickness (BF) and shear force (SF) using admixed population as reference increased with reference population size, while the results for CWT and muscle pH at 24 hours after slaughter (pH) were equivocal with respect to the relationship between accuracy and reference population size, although overall accuracy was similar to that using the BS as the reference.

Genome-wide association study to identify canine hip dysplasia loci in dogs.

Korean army dogs are raised for special purposes and have contributed much to society. However, several diseases occur in dogs. Canine hip dysplasia (CHD) is a musculoskeletal disorder that occurs frequently in Korean army dogs and interferes with their activities. If we could control CHD, this would have a positive effect on their performance. This study performed a genome-wide association study (GWAS) in 69 Korean army dogs to find significant loci for CHD using 170K single nucleotide polymorphisms (SNPs). CHD was classified according to the Norberg angle criterion. The control group comprised 62 dogs classified as relatively normal, and 7 dogs with severe CHD formed the case group. From the GWAS analysis, we concluded that SNPs present on chromosome 4 might have a significant impact on the overall expression of canine hip dysplasia.

Erratum to: Comparison of prediction accuracy for genomic estimated breeding value using the reference pig population of single-breed and admixed-breed.

[This corrects the article DOI: 10.5187/jast.2020.62.4.438.].

Genetic diversity and population structure of the Sapsaree, a native Korean dog breed.

BACKGROUND: The Sapsaree is a breed of dog (Canis familiaris) native to Korea, which became perilously close to extinction in the mid-1980s. However, with systematic genetic conservation and restoration efforts, this breed was rescued from extinction and population sizes have been gradually increasing over the past few decades. The aim of this study was to ascertain novel information about the genetic diversity, population structure, and demographic history of the Sapsaree breed using genome-wide single nucleotide polymorphism data. We characterized the genetic profile of the Sapsaree breed by comparison with seven foreign dog breeds with similar morphologies to estimate genetic differentiation within and among these breeds. RESULTS: The results suggest that Sapsarees have higher genetic variance compared with the other breeds analyzed. The majority of the Sapsarees in this study share a discrete genetic pattern, although some individuals were slightly different, possibly as a consequence of the recent restoration process. Concordant results from analyses of linkage disequilibrium, effective population size, genetic diversity, and population structural analyses illustrate a relationship among the Sapsaree and the Tibetan breeds Tibetan terrier and Lhasa Apso, and a small genetic introgression from European breeds. The effective population size of the Sapsaree has contracted dramatically over the past generations, and is currently insufficient to maintain long-term viability of the breed's genetic diversity. CONCLUSIONS: This study provides novel insights regarding the genetic diversity and population structure of the native Korean dog breed Sapsaree. Our results suggest the importance of a strategic and systematic approach to ensure the genetic diversity and the authenticity of the Sapsaree breed.

Mouse orthotopic lung cancer model induced by PC14PE6.

PURPOSE: This study was undertaken to investigate in detail the xenograft mouse orthotopic lung cancer model induced by PC14PE6 adenocarcinoma cells. MATERIALS AND METHODS: Three cell doses (0.5x10(6); 1x10(6); 2x10(6)) of PC14PE6 cells were injected into the lungs of male BALB/c nude mice by the intrathoracic injection method. The lung and other organs, including brain, liver, spleen, kidney, muscle, adrenal gland, and lymph node on knee, were removed and stained with H/E to detect the presence of tumor cells. RESULTS: The reliable tumorigenicity time in the PC14PE6 adenocarcinoma cell-inoculated BALB/c nude mouse was 10 days after intrathoracic injection. The average life span of the three groups after inoculation was 14 days in the 2x10(6) cells inoculum group; 25 days in the 1x10(6) cells inoculum group; and 32 days in the 0.5x10(6) cells inoculum group. The PC14PE6 adenocarcinoma cells induced orthotopic lung cancer limited within the thorax. CONCLUSIONS: This orthotopic lung cancer model is an efficient cancer model with easy inoculation methods, rapid and high tumorigenicity, and simple monitoring methods for metastasis.