The PTM profiling of CTCF reveals the regulation of 3D chromatin structure by O-GlcNAcylation.

CCCTC-binding factor (CTCF), a ubiquitously expressed and highly conserved protein, is known to play a critical role in chromatin structure. Post-translational modifications (PTMs) diversify the functions of protein to regulate numerous cellular processes. However, the effects of PTMs on the genome-wide binding of CTCF and the organization of three-dimensional (3D) chromatin structure have not been fully understood. In this study, we uncovered the PTM profiling of CTCF and demonstrated that CTCF can be O-GlcNAcylated and arginine methylated. Functionally, we demonstrated that O-GlcNAcylation inhibits CTCF binding to chromatin. Meanwhile, deficiency of CTCF O-GlcNAcylation results in the disruption of loop domains and the alteration of chromatin loops associated with cellular development. Furthermore, the deficiency of CTCF O-GlcNAcylation increases the expression of developmental genes and negatively regulates maintenance and establishment of stem cell pluripotency. In conclusion, these results provide key insights into the role of PTMs for the 3D chromatin structure.

Effects of Lactobacillus Lactis Supplementation on Growth Performance, Hematological Parameters, Meat Quality and Intestinal Flora in Growing-Finishing Pigs.

OBJECTIVE: The study was conducted to assess the effect of supplementation with Lactobacillus lactis (LL) on growth performance, hematological parameters, meat quality and intestinal flora in pigs from growing until slaughter. METHODS: A total of 72 growing pigs (30.46 ± 3.08 kg) were randomly assigned to 3 groups (including 3 pens for each group, with 8 pigs in each pen). The three treatments comprised a basal diet (O-0) and two experimental diets supplemented for 14 weeks with 0.01% (O-100) and 0.03% (O-300) LL, respectively. RESULTS: The final body weights of the pigs in the O-100 and O-300 groups were significantly higher (p < 0.05) than those of the O-0 group. In the grower phase, the average daily weight gain (ADG) and average daily feed intake (ADFI) of pigs fed the O-300 diet were higher (p < 0.05) than those of pigs fed the O-0 diet during the grower phase. BUN and MDA were significantly higher (p < 0.05 for all) in the O-0 group than in the O-100 and O-300 groups during the grower phase. No difference (p > 0.05) was observed in the hematological parameters among the three groups during the finisher phase. Counts of LL in the stomach were significantly higher (p < 0.05) in the O-300 group than in the O-0 group. Counts of Escherichia coli in the jejunum were significantly higher (p < 0.05) in the O-0 group than in the O-300 group. Furthermore, the hardness, cohesiveness, gumminess and resilience of longissimus dorsi muscle collected from pigs fed the O-300 diet were higher (p < 0.01; p = 0.024; p = 0.003; p = 0.014, respectively) than those of tissue collected from pigs fed the O-0 diet. CONCLUSION: Dietary LL supplementation increased final body weight, increased ADG in the grower phase and enhanced meat quality.