Association Analysis and In Silico Functional Predictions of RMDN2 Variants in Chickens

Objective: Microtubule dynamics regulator protein 2 (RMDN2) plays a crucial role in cell division, cytoskeleton maintenance, and various other cellular processes, establishing it as a candidate gene influencing chicken follicle development in our previous studies.This research aims to explore single-nucleotide polymorphisms (SNPs), perform phylogenetic analysis, and assess sequence characteristics of RMDN2, offering valuable insights for molecular markerassisted breeding and enhancing the understanding of its regulatory mechanisms.Methods: SNPs within the RMDN2 coding sequence (CDS) region were identified in an F2 resource population.Bioinformatics tools were employed to investigate the effects of SNP mutations on the structure and function of RMDN2 protein, and a phylogenetic tree was constructed to elucidate the potential mechanisms underlying the role of RMDN2 in chicken laying traits.Results: Four novel exonic SNPs were discovered: SNP1 (c.250G>A, p.Val84Ile), SNP2 (c.270G>C, p.Lys90Asn), SNP3 (c.533G>T, p.Gly178Val), and SNP4 (c.606G>A).The heterozygous genotypes of SNP1, SNP3, and SNP4 were significantly associated with increased egg number at 66 weeks (EN66) (p < 0.05).In contrast, the heterozygous genotype of SNP2 is associated with higher body weight at first egg (BWFE) (p < 0.05).Notably, the H1H1 haplotype combination was associated with lower BWFE, body weight at 105 days (BW105), and first egg weight (FEW) (p <0.05).Missense mutations in SNP1, SNP2, and SNP3 were speculated to potentially influence the hydrophilic/hydrophobic properties, transmembrane regions, functional domains, and secondary structure of the RMDN2 protein, A c c e p t e d A r t i c l e potentially reducing its stability.Phylogenetic analysis demonstrated 100% sequence homology between chicken and quail, with substantial conservation within species of the same order, but a marked decrease across different taxonomic orders. Conclusion:These findings enrich the candidate gene pool for regulating chicken laying traits.However, further validation through in vivo and in vitro experiments remains necessary to strengthen the theoretical foundation for molecular breeding strategies.