Genomic structure, polymorphism and expression of ACCN1 and ACCN3 genes in the horse.

The research article discusses the genomic structure, polymorphisms, and expression patterns of two cation channel genes (ACCN1 and ACCN3) in horses, which are linked to pain transmission and may be related to strenuous exercise-induced pain reactions in equines.

Amiloride-sensitive Cation Channel, Neuronal (ACCN) Gene Family

• ACCN genes are present in sensory neurons and serve as receptors of the protons that can be found in muscular tissues.
• They play significant roles in pain transmission through pH sensitive neurons.
• In horses, ACCN may contribute to the pain responses following strenuous exercises, as muscle exertion produces lactic acid which could interact with these ACCN channels.

Determining ACCN Gene Structure in Horses

• The researchers determined the full sequences of ACCN1 and ACCN3 genes in the horse and found them to be 2.6 kb and 2.1 kb long, respectively.
• They identified that ACCN1 has an open reading frame of 1539 bp and contains 10 exons while ACCN3 has an open reading frame of 1602 bp and contains 11 exons.

Expression and Polymorphism of ACCN Genes

• While ACCN1 and ACCN3 exhibit a universal expression across various tissues, ACCN1 shows a higher expression level in the spinal cord.
• An alternative splicing variant for ACCN3 was observed that could result in two distinct protein isoforms.
• Ten single nucleotide polymorphisms (SNPs) were identified for ACCN1; five in the coding and five in the non-coding region, without any resultant amino acid changes.
• Three SNPs were identified for ACCN3 and were found to result in amino acid changes.

Promoter Sequences of ACCN Genes

• The in silico analysis suggested that the promoter sequences of the equine ACCN1 and ACCN3 genes bear resemblance to those found in other mammalian species.
• The ACCN1 gene, in particular, exhibited a very similar promoter sequence structure to that seen in other mammals.