Polymorphism of the RNF165 Gene in American Mink (Neogale vison) as a Potential Factor Responsible for Resistance to Infection with the Aleutian Mink Disease Virus

<b>Background:</b> Advances in American mink (<i>Neogale vison</i>) genomics have identified candidate genes linked to disease resistance, including <i>RNF165</i>, which is involved in immune response and virus-host interactions. Objectives: This study aimed to characterize genetic variation within the <i>RNF165</i> (Ring Finger Protein 165) gene in farmed and wild mink to identify polymorphisms potentially associated with resistance to Aleutian mink disease virus (AMDV). <b>Methods:</b> Two groups of mink were analyzed: farmed animals from Latvia (<i>n</i> = 50) and wild animals (<i>n</i> = 20) from Poland. The presence of viral DNA was verified by PCR amplification targeting the <i>VP2</i> and <i>NS1</i> viral protein genes. To assess polymorphism within <i>RNF165</i>, primers spanning eight exons were designed, optimized, and applied in PCR amplification. PCR products were sequenced and subjected to bioinformatic analysis. <b>Results:</b> Two single nucleotide polymorphisms were identified: a synonymous substitution at c.G141A and a missense mutation c.G596A (p.R199K). Both variants were present in farmed and wild populations; however, the G allele at position c.141 was nearly twice as frequent in farmed mink compared to wild mink (<i>p</i> < 0.05). In silico functional prediction (SNAP2) indicated that the p.R199K mutation may moderately affect RNF165 protein function. <b>Conclusions:</b> Owing to its high conservation and role in immune regulation, <i>RNF165</i> may serve as a promising candidate gene for molecular selection in breeding programs aimed at enhancing resistance to Aleutian mink disease (AMD).