GENOTYPING OF NATIVE AND IMMUNOLOGICALLY CASTRATED GILTS BY QTL-MARKER OF RYR1 AND CTSD
Authors: Budakva Yelyzaveta 
Published: June 2022

In the study conducted, the allele effect of the SNP studied was determined (Single Nucleotide Polymorphism) ryanodine receptor gene 1 RYR1 (g.1843 C>T) and cathepsin gene D CTSD (g.70 G>A) for fattening performance of the control (native) and experimental (immunologically castrated) groups of gilts the final hybrid (Large White × Landrace) × Maxgro. It was held a population analysis of polymorphism using software «GenAlEX6» to find out if the allele effect of the investigated is different (SNP) on the productivity of hybrid gilts - of the native in the number of samples (n=38) and immunologically castrated (n=30) grown in conditions of LLC SPE "Globinsky Pig Farm". Laboratory tests are carried out in the laboratory of genetics the basis of the Institute of Pig Breeding and Agricultural Production NAAS of Ukraine. Due to the fact that information on polymorphism according to QTL markers of ryanodine receptor 1 and cathepsin D in the population of immunologically castrated pigs that are bred in Ukraine is absent requires an experiment to determine which alleles will be determined as desirable in marker breeding of pigs under conditions of immunological castration. Polymorphism of the studied gene RYR1 (g.1843 C>T) and CTSD (g.70 G>A) was determined by the method of PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) analysis. Researched by QTL (quantitative trait loci) ryanodine receptor gene 1 RYR1 (g.1843 C>T) - is a marker gene whose polymorphism is associated with the quality of meat, and is responsible for the developed muscles of the carcass and limbs as well as pigs' tendency to stress (PSS) – RYR1TT. In the SNP, the RYR1 allele T frequency was 0.941 and is higher than the allele frequency C of 0.059. The genotype RYR1СС was found in only one native pig with (ADG=0.677g/163day). The genotype RYR1TT with a frequency of 0.94 genotypes prevails RYR1СС =0.06. Gilts with genotype RYR1TT are stress-sensitive. Indicator (ADG) for immunologically castrated gilts is (ADG=0.875g/149day) with a significant difference with uncastrated pigs in indicator of – average growth rate 156days. The PIC level for locus RYR1 is low at 0.10, which limits its use for associated studies. No pigs with the RYR1CC genotype were found among the research team. However, it was found only in 1 head of female pigs – the control group as a result of a single case in this population. Animals with the genotype RYR1TT 7 days earlier reached a live weight of 100 kg from the control group. The gene of cathepsin D CTSD (g.70 G>A) – is associated with precocity and efficiency of feed use. The breed character of a frequency distribution of gene alleles was established CTSD (g.70 G>A) was 0.595 by G allele frequency significantly prevailing allele A 0.405 with the index of the information content of PIC loci at the optimal level of 0.37. A research group of pigs with monomorphic genotype CTSDGG prevailed the control group (ADG=0.770g/159day) by age reaching a live weight of 100 kg in 151 days with an average daily increase of 0.808g. A similar situation was formed as a result of the average daily increase in experimental pigs with genotype CTSDGА 0.879 g. with the same age, reaching a live weight of 100 kg in 147 days (ADG=0.858g; 0.879/147day) and the average growth rate other than uncastrated gilts. Hybrid pigs with genotype CTSDGА=0.85 genotypes prevail CTSDGG with a frequency of 0.19.