Molecular Genetic Mechanism Analysis Of Dewclaw Overgrowth Of Sow

Pigs dewclaw in the evolution of the process of serious degradation,the main role is to assist the main hoof to bear the weight of pigs and maintain their physical balance.When the sow dewclaw overgrowth,prone to mechanical damage,which can not stand and diet,secondary to pregnant sows abortion,lactating sow malnutrition,etc.,so that sows and future generations of piglets have an impact on all aspects of performance,also led to sow earlier eliminated,which brought great economic losses to farming enterprises.However,the molecular genetic mechanism of sow dewclaw overgrowth is not clear.In order to analyze the genetic mechanism of dewclaw overgrowth of Yorkshire sow pigs,in this study the Illumina porcineSNP80 BeadChip was typed by 242 dewclaw normal individuals and 233 dewclaw overgrowth individuals in Yorkshire sow pigs,case-control analysis based on univariate mixed linear model was performed using GEMMA software and Bonferroni correction was used to determine the significance threshold.The results showed that seven SNPs were detected at significant levels of chromosomes（P<1.99E-05）,the QTL is located on the SSC13 in the 2.43 Mb region between 140.69 Mb and 143.12 Mb.Among them,the most significant association of the SNP site WU₁0.2₁3₁43119423 is located within the first intron of the gene NRROS（P=1.09E-06）.In order to further narrow the QTL interval,haplotype b lock analysis and linkage disequilibrium analysis were used to fine position.Finally,the Q TL was mapped to the region of 141.29 Mb to 143.28 Mb of SSC13 in the range of 1.99 Mb,which is the smallest QTL interval currently obtained in this study.By searching the QTL region in the Ensembl database,the region contains a total of 17 genes and can be used as a candidate gene for dewclaw overgrowth.Among them,APOD gene in the human skin of the stratum corneum expression,and with the skin part of the genetic disease horny related,the gene has a high correlation with the pathogenesis of dewclaw overgrowth.APOD gene can be used as a potentially important candidate gene in the identification of late pathogenic genes.A total of nine SNPs were detected in the exon region and 1 kb upstream of the candidate gene APOD.Wherein the predicted transcription initiation s ite is located at the insertion deletion deletion SNP c.ins/del51（13:142075529-142075580）and SNP c.A>G（13:142076039）located within the predicted transcription factor active regionFor the first time,we found QTL and candidate genes that affected the dewclaw overgrowth of Yorkshire sow pigs.This provides a basis for the identification of late pathogenic genes and key mutations,which provides a reference and bedding for the analysis of the molecular genetic mechanism of sow dewclaw overgrowth.