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The number of Sertoli cells in the testis is a major regulator on the sperm production capacity. MicroRNAs (miRNAs) participate in regulating the proliferation and apoptosis of porcine immature Sertoli cells. However, the functions and mechanisms of action of most identified miRNAs in porcine Sertoli cells remain largely unknown. In the present study, based on our previous results from an EdU-based high-content screening assay, we further studied the mechanism of action of miR-191 on the proliferation and apoptosis of porcine immature Sertoli cells through flow cytometry, Western blotting, and dual-luciferase activity analyses. The results demonstrated that overexpression of miR-191 promoted cell cycle progression from G 1 phase to the S and G 2 phases, enhanced cell proliferation, and inhibited apoptosis in the porcine immature Sertoli cells, whereasmiR-191 inhibition resulted in the opposite effects. The results from a luciferase reporter assay showed that miR-191 directly targeted the 3'-UTR of theBDNF gene. BDNF knockdown also promoted cell cycle progression to the S phase, cell proliferation and inhibited cell apoptosis, which were consistent with the effects of the miR-191overexpression. A co-transfection experiment showed that BDNF knockdown abolished the effects of miR-191 inhibition. Furthermore, both miR-191 overexpression and BDNFinhibition elevated the phosphorylation of PI3K and AKT, the key components of the PI3K/AKT signaling pathway, whereas BDNFinhibition offset the effects of the miR-191 knockdown. Overall, these data indicated that miR-191 promotes cell proliferation and inhibits apoptosis in porcine immature Sertoli cells by targeting theBDNF gene through activating the PI3K/AKT signaling pathway. This study provides a novel scientific basis for further investigation on the biological functions of miR-191 on porcine spermatogenesis.

Genomic selection is a form of marker-assisted selection in which genetic markers covering the entire genome are used so that all quantitative trait loci are in linkage disequilibrium with at least one marker. Genomic selection improves the efficiency and accuracy of breeding and it is widely used in purebred breeding across many animal species. However, some studies indicate that the accuracy of genome selection in cross breeding needs to be improved,especially in cross population. As one of the most extensive breeding methods employed in the swine industry, cross breeding has significant, potential research and economic value to further improve its performance by combining with genomic selection. In this review, we summarize the application of genomic selection in pigs, and elucidate the genomic selection deficiencies in breeding hybrid pigs. This review will also provide valuable insights for the future application and improvement of genomic selection in pig cross breeding.

In testicular tissue, immature Sertoli cell proliferation ability determines the size of mature Sertoli cell populations, which further regulates the spermatogenesis in the adult male animals. Studies have demonstrated that microRNAs (miRNAs) participate in the regulation of the immature Sertoli cell proliferation and apoptosis, but the functions of most identified miRNAs remain unclear. In this study, based on previous RNA-seq results, we analyzed the regulatory role (s) of miR-362 in proliferation and apoptosis of porcine immature Sertoli cells. The ZFN644 gene was predicted to be a target gene of miR-362 using bioinformatics methods. The expression levels of miR-362 and ZNF644 gene were measured using qRT-PCR assay in developing porcine testicular tissues and in immature Sertoli cells transfected with either miR-362 mimic or miR-362 inhibitor. The dual luciferase reporter assay was used to determine the regulatory relationship between miR-362 and ZNF644. The results showed that a putative target site of miR-362 was located in the 3'UTR of ZNF644. The expression of miR-362 was significantly and negatively correlated with ZNF644 expression in the developing porcine testicular tissues. Co-transfection of miR-362 and psiCHECK2-ZNF644-WT 3'UTR luciferase vector significantly suppressed luciferase activity. The ZNF644 gene expression level was significantly regulated by miR-362, demonstrating that miR-362 targets ZNF644 gene and inhibits its expression in porcine immature Sertoli cells. Flow cytometry, CCK8, and EdU assays were used to measure the effects of over-expression of miR-362 or knockdown of ZNF644 on porcine immature Sertoli cell proliferation; Annexin V-FITC/PI staining assays and qRT-PCR technology were used to test the apoptosis and the expression levels of cell survival-related genes, respectively. Over-expression of miR-362 and knockdown of ZNF644 arrested the porcine immature Sertoli cells in G 1 and G 2 phases of the cell cycle, respectively, and inhibited proliferation, enhanced apoptosis in the porcine immature Sertoli cells, and significantly regulated the expression levels of cell survival-related genes. Taken together, these data indicate that miR-362 inhibits proliferation and promotes apoptosis in porcine immature Sertoli cells by targeting the ZNF644 gene, thereby providing the scientific basis for further study on the function(s) of miR-362 in the porcine spermatogenesis.

Ubiquitin (Ub) is an important signaling protein. Recent studies have shown that Ub can be enzymatically phosphorylated at S65, and that the resulting pUb exhibits two conformational states-a relaxed state and a retracted state. However, crystallization efforts have yielded only the structure for the relaxed state, which was found similar to that of unmodified Ub. Here we present the solution structures of pUb in both states obtained through refinement against state-specific NMR restraints. We show that the retracted state differs from the relaxed state by the retraction of the last β-strand and by the extension of the second α-helix. Further, we show that at 7.2, the pK a value for the phosphoryl group in the relaxed state is higher by 1.4 units than that in the retracted state. Consequently, pUb exists in equilibrium between protonated and deprotonated forms and between retracted and relaxed states, with protonated/relaxed species enriched at slightly acidic pH and deprotonated/retracted species enriched at slightly basic pH. The heterogeneity of pUb explains the inability of phosphomimetic mutants to fully mimic pUb. The pH-sensitive conformational switch is likely preserved for polyubiquitin, as single-molecule FRET data indicate that pH change leads to quaternary rearrangement of a phosphorylated K63-linked diubiquitin. Because cellular pH varies among compartments and changes upon pathophysiological insults, our finding suggests that pH and Ub phosphorylation confer additional target specificities and enable an additional layer of modulation for Ub signals., Competing Interests: The authors declare no conflict of interest.

Jintang black goat (Capra hircus) is an indigenous breed of Sichuan province of China. It is the first time that the complete mitochondrial genome sequence of Jintang black goat is reported in this work, which is determined through the PCR-based method. The total length of the mitogenome is 16,813 bp, which contains two ribosomal RNA genes, 22 tRNA genes, 13 PCGs, and a control region (D-loop region). The total base composition of Jintang black goat mitochondrial genome is 33.52% A, 13.13% G, 27.35% T, and 26.00% C, and in the order A > T > C > G. The complete mitochondrial genome of Jintang black goat provides an important data in genetic mechanism and the evolution genomes.

Ubiquitin-proteasome pathway (UPP) is the main pathway of protein degradation in eukaryotic cells. The UPP plays very important roles in cell cycle progression, apoptosis, stress response and growth and development through regulating protein interaction, protein activity, protein localization and signal transduction. Previous studies have shown that the UPP is essential for regulating acrosome and tail biogenesis during spermatogenesis in human and animals. The dysregulation of UPP during spermatogenesis results in sperm deformity and reduced sperm motility and leads to reproductive system diseases such as oligospermatism, infertility and testicular tumors. In this review, we summarized the signal transduction and regulation mechanism of UPP in spermatogenesis, which may provide references for future studies.

Congjiang miniature pig is one of the most important local pig breeds in China. It is the first time that the complete mitochondrial genome sequence of Lantang pig is reported in this work, which is determined through the PCR-based method. The total length of the mitogenome is 16,772 bp, which contains 1 control region (D-loop region), 2 ribosomal RNA genes, 13 PCGs and 22 tRNA genes. The total base composition of Congjiang miniature pig mitochondrial genome is 34.78% for A, 26.21% for C, 25.78% for T and 13.22% for G and in the order A>C>T>G. The complete mitochondrial genome of Congjiang miniature pig provides an important data in genetic mechanism and the evolution genomes.

Guanling pig is one of the native breeds in Guizhou Province in China. The compete mitochondrial genome of Guanling pig was determined by polymerase chain reaction (PCR). The result shows that the compete mitochondrial genome of Guanling pig is 16,731 bp, and it contains a major non-coding control region (D-Loop region), 2 ribosomal RNA genes, 13 protein-coding genes (PCGs) and 22 transfer RNA genes. The mitochondrial DNA control region of the Guanling pig contains repeat motif TAC ACG TGC G, 5' nucleotide of the first repeat is at the position 814 bp, and the repeat number is 13. The mitochondrial genome of Guanling pig subsequently provides important information in genetic mechanism and the evolution genomes.

Luchuan pig is one of the famous native breeds in China. In this study, we report the complete mitochondrial genome sequence of Luchuan pig for the first time, which is determined through the PCR-based method. The total length of the mitogenome is 16,710 bp with the base composition of 34.67% A, 13.33% G, 25.82% T and 26.18% C, and an A + T (60.48%)-rich feature is detected, which contains 1 control region (D-loop region), 2 ribosomal RNA genes, 13 PCGs and 22 tRNA genes. The complete mitochondrial genome of Luchuan pig provides an important data in genetic mechanism and the evolution genomes.

Lantang pig is a native breed of Guangzhou Province in China. It is the first time that the complete mitochondrial genome sequence of Lantang pig is reported in this work, which is determined through the PCR-based method. The total length of the mitognome is 16,709 bp, which contains 2 ribosomal RNA genes, 22 tRNA genes, 13 PCGs and 1 conntrol region (D-loop region, Table 1). The total base composition of Lantang pig mitochondrial genome is 34.69% for A, 26.18% for C, 25.82% for T and 13.31% for G, in the order A>C>T>G. The complete mitochondrial genome of Lantang pig provides an important data in genetic mechanism and the evolution genomes.