Results from the study showed that SNPs found in the HNMT gene significantly increased carnosine levels in chickens. (Image source: Adobe Stock)
Poultry meat is one of the most sought-after foods worldwide, valued not only for the nutrition it provides, but also for its palatability
Besides being popular for its protein, vitamin and mineral content, poultry meat also contains bioactive compounds, particularly carnosine and anserine that determine its palatability. Both these compounds contribute to the umami taste, known to be a key component of meat flavour, with their quantities primarily being influenced by genetics. Moreover, their levels tend to vary among breeds and are often used to determine meat quality.
Besides breed, the carnosine levels in meat tend to depend on a variety of other factors including muscle fibre type and whether the meat is raw or cooked. Meat from the breast and thigh muscles are usually found packed with carnosine, with concentrations being greater in Korean native chickens and Thai indigenous and hybrid native chickens.
On the other hand, anserine is generally found in the skeletal muscles of chickens, cattle and certain species of fish. Its levels are often higher in breast meat compared to thigh meat, given its function in buffering proton production in breast muscle. Moreover, similar to carnosine, the levels of this compound in meat can be determined by the type of meat and chicken line.
A recent study conducted at Chungnam National University aimed to explore the genetic and environmental factors that affect carnosine and anserine content in meat in Korean native chicken red brown line (KNC-R). Single nucleotide polymorphisms (SNPs) were identified in the histamine-N-methyl transferase (HNMT) and histamine-N-methyl transferase-like (HNMT-like) genes and their association with the carnosine and anserine content was studied.
Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods were used to genotype one synonymous SNP (rs29009298C/T) of the HNMT gene. On the other hand, PCR allele competitive extension (PACE) genotyping technology was used to genotype four missense SNPs (rs734406537G/A; rs736514667A/G; rs15881680G/A and rs316765035T/C) of the HNMT gene, and one missense SNP rs737657949A/C of the HNMT-like gene.
Results from the study showed that SNPs found in the HNMT gene significantly increased carnosine levels in chickens. Moreover, breeding methods were also found to influence carnosine content to a great extent, with female chickens showing comparatively higher levels than males.
Two associations could be identified between the genotypes of the synonymous SNP: rs29009298C/T, missense SNP rs736514667A/G of the HNMT gene and the content of carnosine. Given its efficiency and precision, PACE technology was therefore regarded as a useful and reliable tool that could be used for the improvement of livestock systems.
