Cathepsins, growth hormone-releasing hormone (GHRH) and leptin receptor (LEPR) genes have been receiving increasing attention as potential markers for meat quality and pig performance traits. This study investigated the allele variants in four cathepsin genes (CTSB, CTSK, CTSL, CTSS), GHRH and LEPR in pure-bred Ukrainian Large White pigs and evaluated effects of the allele variants on meat quality characteristics. The study was conducted on 72 pigs. Genotyping was performed using PCR–RFLP technique. Meat quality characteristics analysed were intramuscular fat content, tenderness, total water content, ultimate pH, crude protein and ashes. A medium level of heterozygosity values was established for GHRH and LEPR genes which corresponded to very high levels of informativeness indexes. Cathepsins CTSL, CTSB and CTSK had a low level of heterozygosity, and CTSS did not segregate in this breed. Association studies established that intramuscular fat content and tenderness were affected by the allele variance in GHRH and LEPR but not by CTSB and CTSL genes. The GHRH results could be particularly relevant for the production of lean prime cuts as the A allele is associated with both, a lower meat fat content and better tenderness values, which are two attributes highly regarded by consumers. Results of this study suggest that selective breeding towards GHRH/AA genotype would be particularly useful for improving meat quality characteristics in the production systems involving lean Large White lines, which typically have less than 2 % intramuscular fat content.

Aim. To determine genetic characteristics of the Mirgorod pig breed by analysis of 25 SNPs of 22 genes and to conduct the associative analysis of genes MC4R (SNP c.1426 G > A), LEP (SNP g.2845 А ˃ Т), GH (BsuRI- polymorphism), CTSF (SNP g. 22 G > C) with productive traits of animals. Methods. Blood samples of pedigree Mirgorod pigs, bred at SI «Experimental farm named after Decemberists», Poltava region, were used for the studies. DNA genotyping was performed by PCR-RFLP and TaqMan. Results. Specifi c features of the breed were determined in terms of gene allele frequencies, high level of genetic variability (He – 0.326) and allelic diversity (mean number of alleles per locus – 1.96). The KPL2/m allele that causes genetic anomaly of ISTS is absent among investigated Mirgorod pigs, and the recessive RYR1 g.1843T allele, responsible for stress sensitivity of pigs, occurs at a low frequency (0.04). Unlike other breeds, a relatively high frequency of the minor allele g.15A (0.16) of CTSK and polymorphism of the LEP gene (SNP g.3996 T > C) (He – 0.455) was observed. Statistically signifi cant associations of polymorphisms have been established: MC4R (SNP c.1426 G > A) with age of gaining 100 kg, the thickness of backfat and the Eye Muscle Area, GH/BsuRI with the age of gaining 100 kg, and CTSF (SNP g. 22G > C) with Eye Muscle Area. There was a trend of statistically signifi cant differences between groups of pigs with different genotypes of LEP (SNP g.2845 А ˃ Т) and the thickness of the backfat (p = 0.09). Conclusions. It is reasonable to carry out the restoration of the gene pool of the Mirgorod pig breed, taking into account the SNPs of the studied genes and their associations with the productive traits. It is expedient to give preference to pigs with SNP genotypes с.1426 MC4R GA, MC4R AA, g. 22 CTSF CC, g.2845 LEP TT for breed reproduction.

No abstract

Aim. To study the distribution of genotypes by polymorphisms of the leptin (LEP SNP g.3469 T > C, LEP SNP g.2845 A > T) and cathepsin F (CTSF SNP g.22 C > G) genes according to the quality levels PSE, NOR and DFD meat in Large White pig breed of Ukrainian selection and to fi nd associations of genetic markers with the total indicator of meat quality. Methods. We studied meat samples (m. longissimus dorsi) from 102 pigs of Ukrainian Large White breed, raised to the weight at slaughter of 120 ± 5 kg in the experimental farm “Stepne” of the Poltava region, Ukraine. The ranking of muscle tissue was carried out according to the total indicator of meat quality (TM). PCR-RFLP analysis was used for DNA typing. The associations between genetic markers and TM were determined using ANOVA. Results. Genetic population analysis of Large White breed pigs of Ukrainian selection by genetic markers LEP SNP g.3469 T > C, LEP SNP g.2845 A > T and СTSF SNP g.22 C > G was carried out. The informative value of LEP SNP g.2845 A > T and СTSF SNP g.22 C > G, according to the calculated polymorphism information content, was optimal for associative studies (PIC = 0.311 and 0.373, respectively). The distribution of meat samples by quality levels PSE, NOR and DFD was performed. Most of them had traits of moderately expressed (n = 22) and weakly expressed (n = 59) PSE defect (light, soft, exudative meat). The calculated coeffi cients of Chuprov’s mutual conjugation between the genotypes for the studied SNPs and meat quality levels showed a moderate relationship between the genotypes for LEP SNP g.2845 A > T and CTSF SNP g.22 C > G and meat quality levels, К = 0.26 and 0.24, respectively. According to the results of ANOVA, the differences were found between homozygous and heterozygous CTSF SNP g.22 C > G genotypes in terms of the total indicator of meat quality. Conclusions. The meat of heterozygous pigs for CTSF SNP g.22 C > G (g.22GC) is characterized by a higher total indicator of meat quality (4.6) compared to the meat of homozygous animals g.22GG (4.2, p ≤ 0.05) and g.22CC (3.9, p ≤ 0.01).

The aim of our work was to develop PCR test systems for the identification and differentiation of the Piscichlamydia salmonis and Clavochlamydia salmonicola, species, that are known epitheliocystis infection agents of gill and fish skin diseases, characterized by the presence of specific ‘inclusions’ in the epithelial cells of the gills. To date, the diseases of fish associated with chlamydial infections have been detected in more than 90 species of freshwater and marine fish worldwide. For now, there is no available information on the prevalence of Piscichlamydia salmonis and Clavochlamydia salmonicola, which can cause epitheliocystis of commercially important aquaculture species in Ukraine. Identification of these pathogens is possible only using molecular genetic methods. As a result of our research, we got PCR tests for the identification and species differentiation of Piscichlamydia salmonis and Clavochlamydia salmonicola. The use of diagnostics for the identification of Piscichlamydia salmonis and Clavochlamydia salmonicola makes chlamydial infections monitoring among various fish species possible and it will increase the economic efficiency of fish farms.