Polydactyly is a genetic abnormality that affects both pig welfare and industry profits. Despite efforts to explore the genetic basis of pig polydactyly, progress remains limited. In this study, we analyzed a group of Large White pigs with postaxial polydactyly, including 29 cases and 79 controls from 24 families. High-depth sequencing was performed on 20 pigs, while low-depth sequencing was improved through imputation for the remaining pigs. A genome-wide association study (GWAS) and genetic differentiation were conducted using the resequencing dataset, resulting in the identification of 48 significantly associated SNPs and 27 candidate regions. The genetic differentiation regions on chromosomes 5 and 18, which harbored GWAS-identified SNPs, were delineated as confidence regions. The confidence region at Chr18: 1.850–1.925 Mb covers the fifth intron of LMBR1, a gene that contains an important regulatory element for SHH, known as ZRS. Mutations in this ZRS have been found to cause polydactyly in animals and humans. Therefore, we propose LMBR1 as a prospective candidate gene for postaxial polydactyly. These findings emphasize the importance of exploring the role of ZRS within LMBR1 in the pathogenesis of polydactyly in pigs.

中文翻译：

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全基因组重测序揭示了大白猪轴后多指的候选基因

多指症是一种遗传异常，影响猪的福利和行业利润。尽管人们努力探索猪多指的遗传基础，但进展仍然有限。在本研究中，我们分析了一组患有轴后多指畸形的大白猪，包括来自 24 个家系的 29 例病例和 79 例对照。对 20 头猪进行了高深度测序，同时通过对其余猪进行插补改进了低深度测序。使用重测序数据集进行全基因组关联研究 (GWAS) 和遗传分化，鉴定出 48 个显着相关的 SNP 和 27 个候选区域。5 号和 18 号染色体上的遗传分化区域包含 GWAS 鉴定的 SNP，被描绘为置信区域。Chr18: 1.850–1.925 Mb 的置信区域覆盖LMBR1的第五个内含子，该基因包含SHH的重要调控元件（称为 ZRS）。已发现该 ZRS 的突变会导致动物和人类出现多指症。因此，我们建议LMBR1作为轴后多指畸形的潜在候选基因。这些发现强调了探索LMBR1内 ZRS在猪多指发病机制中的作用的重要性。