Abstract. The UBX domain containing protein 1-like gene (UBXN1) promotes the degradation of
myofibrillar proteins during meat maturation, which affects meat water-holding capacity (WHC). This study aims to identify functional mutations in
UBXN1 promoter region, which affects the transcription activity and therefore the
WHC. Firstly, we confirmed that the UBXN1 expression level was positively
associated with WHC. Individuals with high and low WHC (n=16 per
group) were selected from 168 Duroc × Large White × Yorkshire (D × L × Y) crossbred pigs. The UBXN1 promoter region
was comparatively sequenced using DNA pools from these two groups, and a
mutation ca. −379T > G was revealed that had reverse allele distribution.
The single nucleotide polymorphism (SNP) was then genotyped in the abovementioned population. TT genotype individuals exhibited higher UBXN1 mRNA level
and higher WHC compared with GG genotype ones. Further luciferase assay
confirmed that TT genotype promoter had higher activity. Moreover, the
degradation of cytoskeletal framework proteins of muscle cells like
desmin, synemin, dystrophin, and vinculin was higher in TT genotype individuals than GG ones. In
conclusion, we identified a SNP in the UBXN1 gene promoter that contributes to
WHC improvement and pork quality. And UBXN1 is a strong candidate gene in
regulation of pork WHC.