The Identification And Function Research Of Different Transcriptions Of PDLIM7 Gene In Qinchuan Cattle

The PDZ and LIM domain 7(PDLIM7) belongs to the Enigma subfamily, which can bind to several signaling molecules via their LIM domains and bind to cytoskeleton through their PDZ domains, functionally. In human,PDLIM7 has been shown to enhance bone morphogenetic responsiveness and regulate p53 protein levels through an SRF/ Pdlim7/MDM2 pathway during tumorigenes. A previous study demonstrated that PDLIM7 protein was important for adult heart function but not for heart valve development, which was in stark contrast to the influence in valve formation of zebrafish. PDLIM7 was in the alkaline pH range of the bovine skeletal muscle protein map and act one member of the Z-line proteins, which are important for muscle physiology. It is worth mentioning that,as with the other Enigma sub-family members, PDLIM7 protein has multiple splicing variants(SVs) and various number of splice isoforms in different species. To date, the exact number of isoforms of PDLIM7 and their functions in the musculature of cattle remain enigmatic.Considering this problem, the aim of this study was to detect the number of the PDLIM7 isoforms in the muscle tissue of QC cattle and study their potential functions including the expression patterns, the sub-cellular localizations and their effects in the differentiation of C2C12 cells,and to provide some new basic basis for the further research of PDLIM7. The results were as follows:1. Herein, we confirmed four different transcripts of PDLIM7 gene in Qinchuan(QC) cattle for the first time. They were expressed variously in different tissues from fetal to adult stages.2. Surprisingly, we detected three novel SNPs(g. 1452 A > G, g. 5034 A > G and g.7127 T > C) that were significantly associated with several growth traits. Interestingly, the relative expression percentages of the four transcripts could also be affected by the SNPs, which illustrated that the SNPs might affect the growth traits through regulating the PDLIM7 isoforms’ expression.3. The major differences of the four isoforms were the presence of the LIM zinc-binding domains and the variable exon4. Sub-cellular localization analysis showed that the EGFP-PDLIM7-SV2 signal was the strongest and dispersed throughout the whole cell, while the other three isoforms were located in the cytoplasm.4.Functional assay revealed that only overexpression of the new-found PDLIM7-SV4 isoform can promote C2C12 cell differentiation while the other three had an inhibitory effect.In summary, we detected and confirmed four transcripts of PDLIM7 gene in QC cattle, whose expression might be affected by the SNPs and function differently in the muscle development. Our study provided essential information for the further PDLIM7 study.